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Page 1: The Northwestern Mutual Life Insurance Company VariableLife

THE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY

May 1, 2017

VARIABLE LIFE

Whole Life

Extra Ordinary Life

Single Premium Life

PROSPECTUSESVariable Life Northwestern Mutual Series Fund, Inc.Fidelity® VIP Mid Cap Portfolio Service Class 2Fidelity® VIP Contrafund® Portfolio Service Class 2Neuberger Berman AMT Socially Responsive PortfolioRussell Investment FundsRussell Investment Funds – LifePoints® Variable Target Portfolio SeriesCredit Suisse Trust Commodity Return Strategy Portfolio

VARIABLE LIFE

90-1898 (0386)

GO PAPERLESS!See back cover for details.

Page 2: The Northwestern Mutual Life Insurance Company VariableLife
Page 3: The Northwestern Mutual Life Insurance Company VariableLife

Page 1 of 1

Northwestern Mutual Series Fund, Inc. International Growth Portfolio

Supplement Dated January 11, 2018

to the Summary Prospectus for the International Growth Portfolio Dated May 1, 2017

The following information supplements the Summary Prospectus for the International

Growth Portfolio of Northwestern Mutual Series Fund, Inc. dated May 1, 2017 (the “Summary Prospectus”), a copy of which you have already received. You should read this Supplement together with the Summary Prospectus. Portfolio Manager Update Effective December 5, 2017, Jed Weiss returned from his leave of absence and has resumed sole responsibility as portfolio manager of the International Growth Portfolio (the “Portfolio”). Accordingly, the “Portfolio Manager” information set forth in the Summary Section for the Portfolio in the Prospectus under “PORTFOLIO MANAGEMENT” is hereby deleted and replaced with the following:

“Portfolio Manager: Jed Weiss, Portfolio Manager, began managing the Portfolio in 2015.”

In addition, effective December 5, 2017, all information relating to Vincent

Montemaggiore is deleted from the Prospectus.

Please retain this Supplement for future reference.

Page 4: The Northwestern Mutual Life Insurance Company VariableLife

Russell Investment Funds

RUSSELL INVESTMENT FUNDSSupplement dated December 21, 2017 to

U.S. SMALL CAP EQUITY FUNDSUMMARY PROSPECTUS DATED May 1, 2017,

As supplemented December 21, 2017

I. SUMMARY PROSPECTUS LEGEND: The legend appearing at the top of the first page of the SummaryProspectus is hereby replaced with the following:

Before you invest, you may want to review the Fund’s Prospectus, which contains more information aboutthe Fund and its risks. You can find the Fund’s Prospectus, Statement of Additional Information (SAI),Annual Report and other information about the Fund online at http://hosted.rightprospectus.com/RIF/. Youcan also get this information at no cost by calling 1-800-787-7354 or by sending an e-mail to:[email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, assupplemented through December 21, 2017, and the Fund’s most recent shareholder report, dated June 30,2017, are all incorporated by reference into this Summary Prospectus.

II. MANAGEMENT: The following replaces the list of money managers in the sub-section entitled“Management” in the Summary Prospectus:

• Ancora Advisors, LLC • Penn Capital Management Company, Inc.

• Copeland Capital Management, LLC • Snow Capital Management L.P.

• DePrince, Race & Zollo, Inc. • Timpani Capital Management LLC

• Falcon Point Capital, LLC

Page 5: The Northwestern Mutual Life Insurance Company VariableLife

Russell Investment Funds

RUSSELL INVESTMENT FUNDSSupplement dated December 21, 2017 to

INTERNATIONAL DEVELOPED MARKETS FUNDSUMMARY PROSPECTUS DATED May 1, 2017,

As supplemented September 14, 2017 and December 21, 2017

I. SUMMARY PROSPECTUS LEGEND: The legend appearing at the top of the first page of the SummaryProspectus is hereby replaced with the following:

Before you invest, you may want to review the Fund’s Prospectus, which contains more information aboutthe Fund and its risks. You can find the Fund’s Prospectus, Statement of Additional Information (SAI),Annual Report and other information about the Fund online at http://hosted.rightprospectus.com/RIF/. Youcan also get this information at no cost by calling 1-800-787-7354 or by sending an e-mail to:[email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, assupplemented through December 21, 2017, and the Fund’s most recent shareholder report, dated June 30,2017, are all incorporated by reference into this Summary Prospectus.

II. PRINCIPAL INVESTMENT STRATEGIES OF THE FUND: The following replaces the secondparagraph sub-section entitled “Principal Investment Strategies of the Fund” in the Summary Prospectus:

Russell Investment Management, LLC (“RIM”) provides or oversees the provision of all investmentadvisory and portfolio management services for the Fund, including developing the investment program forthe Fund and managing the Fund's overall exposures. RIM employs a multi-style (growth, value, market-oriented and defensive) and multi-manager approach for the Fund whereby RIM selects the investmentstrategies for the Fund and utilizes multiple money managers to pursue those strategies. The Fund employsdiscretionary and non-discretionary money managers. The Fund’s discretionary money managers select theindividual portfolio instruments for the assets assigned to them. The Fund’s non-discretionary moneymanagers provide a model portfolio to RIM representing their investment recommendations, based uponwhich RIM purchases and sells securities for the Fund. RIM manages Fund assets not allocated todiscretionary money managers, which include assets managed by RIM to effect the Fund's investmentstrategies and/or to actively manage the Fund's overall exposures to seek to achieve the desired risk/returnprofile for the Fund. RIM may utilize quantitative or qualitative analysis or quantitative models designed toassess Fund characteristics and identify a portfolio which provides the desired exposures or may usestrategies based on indexes that represent the desired exposures, including index replication and optimizedindex sampling (strategies that seek to purchase the securities in an index or a sampling of securities usingoptimization and risk models, respectively). RIM also manages the portion of Fund assets for which theFund's non-discretionary money managers provide model portfolios and the Fund's cash balances. The Fundusually, but not always, pursues a strategy to be fully invested by exposing all or a portion of its cash to theperformance of appropriate markets by purchasing equity securities and/or derivatives, which typicallyinclude index futures contracts and forward currency contracts. The Fund may use derivatives, includingstock options, country index futures and swaps or currency forwards, to (1) manage country and currencyexposure as a substitute for holding securities directly or (2) facilitate the implementation of its investmentstrategy. The Fund may use derivatives to take both long and short positions.

III. PRINCIPAL RISKS OF INVESTING IN THE FUND: The following risk factor is added to the sub-section entitled “Principal Risks of Investing in the Fund” in the Summary Prospectus:

Non-Discretionary Implementation Risk. With respect to the portion of the Fund that is managed pursuant tomodel portfolios provided by non-discretionary money managers, it is expected that trades will be effectedon a periodic basis and therefore less frequently than would typically be the case if discretionary moneymanagers were employed. Given that values of investments change with market conditions, this could causethe Fund's return to be lower than if the Fund employed discretionary money managers with respect to thatportion of its portfolio.

Page 6: The Northwestern Mutual Life Insurance Company VariableLife

IV. MANAGEMENT: The following replaces the list of money managers in the sub-section entitled“Management” in the Summary Prospectus:

• GQG Partners LLC • Pzena Investment Management, LLC

• Janus Capital Management LLC and Perkins InvestmentManagement LLC

• Wellington Management Company LLP

• Numeric Investors LLC

Page 7: The Northwestern Mutual Life Insurance Company VariableLife

Russell Investment Funds

RUSSELL INVESTMENT FUNDSSupplement dated December 21, 2017 to

STRATEGIC BOND FUNDSUMMARY PROSPECTUS DATED May 1, 2017,

As supplemented December 21, 2017

I. SUMMARY PROSPECTUS LEGEND: The legend appearing at the top of the first page of the SummaryProspectus is hereby replaced with the following:

Before you invest, you may want to review the Fund’s Prospectus, which contains more information aboutthe Fund and its risks. You can find the Fund’s Prospectus, Statement of Additional Information (SAI),Annual Report and other information about the Fund online at http://hosted.rightprospectus.com/RIF/. Youcan also get this information at no cost by calling 1-800-787-7354 or by sending an e-mail to:[email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, assupplemented through December 21, 2017, and the Fund’s most recent shareholder report, dated June 30,2017, are all incorporated by reference into this Summary Prospectus.

II. INVESTMENT OBJECTIVE: The following replaces the Investment Objective in the sub-section entitled“Investment Objective in the Summary Prospectus:

Through February 28, 2018, the Fund seeks to provide current income, and as a secondary objective,capital appreciation.

Effective March 1, 2018, the Fund seeks to provide total return.

Page 8: The Northwestern Mutual Life Insurance Company VariableLife

Russell Investment Funds

RUSSELL INVESTMENT FUNDSSupplement dated December 21, 2017 to

MODERATE STRATEGY FUNDSUMMARY PROSPECTUS DATED May 1, 2017,

As supplemented December 21, 2017

I. SUMMARY PROSPECTUS LEGEND: The legend appearing at the top of the first page of the SummaryProspectus is hereby replaced with the following:

Before you invest, you may want to review the Fund’s Prospectus, which contains more information aboutthe Fund and its risks. You can find the Fund’s Prospectus, Statement of Additional Information (SAI),Annual Report and other information about the Fund online at http://hosted.rightprospectus.com/RIF/. Youcan also get this information at no cost by calling 1-800-787-7354 or by sending an e-mail to:[email protected]. The Fund’s Prospectus, dated May 1, 2017, as supplemented throughDecember 21, 2017, SAI dated May 1, 2017, as supplemented through September 14, 2017 and the Fund’smost recent shareholder report, dated June 30, 2017, are all incorporated by reference into this SummaryProspectus.

Page 9: The Northwestern Mutual Life Insurance Company VariableLife

Russell Investment Funds

RUSSELL INVESTMENT FUNDSSupplement dated December 21, 2017 to

BALANCED STRATEGY FUNDGROWTH STRATEGY FUND

EQUITY GROWTH STRATEGY FUNDSUMMARY PROSPECTUS DATED May 1, 2017,

As supplemented September 14, 2017 and December 21, 2017

I. SUMMARY PROSPECTUS LEGEND: The legend appearing at the top of the first page of the SummaryProspectus is hereby replaced with the following:

Before you invest, you may want to review the Fund’s Prospectus, which contains more information aboutthe Fund and its risks. You can find the Fund’s Prospectus, Statement of Additional Information (SAI),Annual Report and other information about the Fund online at http://hosted.rightprospectus.com/RIF/. Youcan also get this information at no cost by calling 1-800-787-7354 or by sending an e-mail to:[email protected]. The Fund’s Prospectus, dated May 1, 2017, as supplemented throughDecember 21, 2017, SAI dated May 1, 2017, as supplemented through September 14, 2017 and the Fund’smost recent shareholder report, dated June 30, 2017, are all incorporated by reference into this SummaryProspectus.

Page 10: The Northwestern Mutual Life Insurance Company VariableLife

Northwestern Mutual Series Fund, Inc. Select Bond Portfolio

Supplement Dated December 15, 2017

to the Summary Prospectus for the Select Bond Portfolio Dated May 1, 2016

The following information supplements the Summary Prospectus for the Select Bond Portfolio of Northwestern

Mutual Series Fund, Inc. dated May 1, 2017 (the “Summary Prospectus”), a copy of which you have already received. You should read this Supplement together with the Summary Prospectus. Portfolio Managers Update Effective October 16, 2017, Maulik Bhansali and Jarad Vasquez joined Troy Ludgood and Thomas O'Connor as co-portfolio managers of the Select Bond Portfolio (the “Portfolio”). Accordingly, the “Portfolio Managers” information set forth in the “PORTFOLIO MANAGEMENT” section is hereby deleted and replaced with the following:

“Portfolio Managers: Troy Ludgood, Senior Portfolio Manager at WellsCap, has been with WellsCap since 2004 and has co-managed the Portfolio since 2014. Thomas O’Connor, CFA, Senior Portfolio Manager at WellsCap, has been with WellsCap since 2000 and has co-managed the Portfolio since 2014. Maulik Bhansali, CFA, Senior Portfolio Manager at WellsCap, has been with WellsCap since 2001 and has co-managed the Portfolio since October 2017. Jarad Vasquez, Senior Portfolio Manager at WellsCap, has been with WellsCap since 2007 and has co-managed the Portfolio since October 2017.”

In addition, Mr. Ludgood plans to transition to a new role effective April 30, 2018 and will no longer serve as a co-portfolio manager of the Portfolio after such date. Accordingly, effective April 30, 2018, all information relating to Mr. Ludgood is deleted from the Prospectus.

Please retain this Supplement for future reference.

Northwestern Mutual Series Fund, Inc. Select Bond Portfolio

Supplement Dated December 18, 2017

to the Summary Prospectus for the Select Bond Portfolio Dated May 1, 2017

The following information supplements the Summary Prospectus for the Select Bond Portfolio of Northwestern Mutual Series Fund, Inc. dated May 1, 2017, as supplemented December 15, 2017 (the “Summary Prospectus”), a copy of which you have already received. You should read this Supplement together with the Summary Prospectus. Revised Reference to Summary Prospectus Date The Summary Prospectus Supplement dated December 15, 2017 ("Supplement") contained a typographical error which incorrectly identified the date of the Summary Prospectus being supplemented as May 1, 2016. This date is hereby corrected so that the title information for the Supplement provides as follows: "Supplement Dated December 15, 2017 to the Summary Prospectus for the Select Bond Portfolio Dated May 1, 2017."

Please retain this Supplement for future reference.

Page 11: The Northwestern Mutual Life Insurance Company VariableLife

Russell Investment Funds

RUSSELL INVESTMENT FUNDSSupplement dated September 14, 2017 to

INTERNATIONAL DEVELOPED MARKETS FUNDSUMMARY PROSPECTUS DATED May 1, 2017,

As supplemented September 14, 2017

I. SUMMARY PROSPECTUS LEGEND: The legend appearing at the top of the first page of the SummaryProspectus is hereby replaced with the following:

Before you invest, you may want to review the Fund’s Prospectus, which contains more information aboutthe Fund and its risks. You can find the Fund’s Prospectus, Statement of Additional Information (SAI),Annual Report and other information about the Fund online at http://hosted.rightprospectus.com/RIF/. Youcan also get this information at no cost by calling 1-800-787-7354 or by sending an e-mail to:[email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, assupplemented through September 14, 2017, and the Fund’s most recent shareholder report, dated June 30,2017, are all incorporated by reference into this Summary Prospectus.

II. PERFORMANCE: The following is added at the end of the second paragraph in the sub-section entitled“Performance” in the Summary Prospectus:

Effective January 1, 2018, RIM will change the Fund’s primary benchmark from the Russell Developed ex-US Large Cap Index (net of tax on dividends from foreign holdings) to the MSCI World ex USA Index (netof tax on dividends from foreign holdings). RIM believes that the MSCI World ex USA Index (net of taxon dividends from foreign holdings) more accurately provides a means to compare the Fund's averageannual total returns to a benchmark that currently best represents the investable global and internationalequity markets.

Page 12: The Northwestern Mutual Life Insurance Company VariableLife

Russell Investment Funds

RUSSELL INVESTMENT FUNDSSupplement dated September 14, 2017 to

BALANCED STRATEGY FUNDGROWTH STRATEGY FUND

EQUITY GROWTH STRATEGY FUNDSUMMARY PROSPECTUS DATED May 1, 2017,

As supplemented September 14, 2017

I. SUMMARY PROSPECTUS LEGEND: The legend appearing at the top of the first page of the SummaryProspectus is hereby replaced with the following:

Before you invest, you may want to review the Fund’s Prospectus, which contains more information aboutthe Fund and its risks. You can find the Fund’s Prospectus, Statement of Additional Information (SAI),Annual Report and other information about the Fund online at http://hosted.rightprospectus.com/RIF/. Youcan also get this information at no cost by calling 1-800-787-7354 or by sending an e-mail to:[email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, assupplemented through September 14, 2017, and the Fund’s most recent shareholder report, dated June 30,2017, are all incorporated by reference into this Summary Prospectus.

II. PERFORMANCE: The following is added at the end of the second paragraph in the sub-section entitled“Performance” in the Summary Prospectus:

Effective January 1, 2018, RIM will change the Fund’s secondary benchmark from the Russell Developedex-US Large Cap Index (net of tax on dividends from foreign holdings) to the MSCI World ex USA Index(net of tax on dividends from foreign holdings). RIM believes that the MSCI World ex USA Index (net oftax on dividends from foreign holdings) more accurately provides a means to compare the Fund’s averageannual total returns to a benchmark that currently best represents the investable global and internationalequity markets.

Page 13: The Northwestern Mutual Life Insurance Company VariableLife

Page 1 of 2

Northwestern Mutual Series Fund, Inc. Large Cap Core Stock Portfolio

Supplement Dated September 27, 2017

to the Summary Prospectus for the Large Cap Core Stock Portfolio Dated May 1, 2017

The following information supplements the Summary Prospectus for the Large Cap Core Stock Portfolio of Northwestern Mutual Series Fund, Inc. (“Fund”) dated May 1, 2017 (the “Summary Prospectus”), a copy of which you have already received. You should read this Supplement together with the Summary Prospectus. Sub-Adviser Change On or about October 27, 2017, Wellington Management Company LLP (“Wellington Management”) will replace Fayez Sarofim & Co. as the sub-adviser for the Fund’s Large Cap Core Stock Portfolio (the “Portfolio”). Wellington Management will provide investment sub-advisory services for the Portfolio pursuant to an Investment Sub-Advisory Agreement approved by the Fund’s Board of Directors on August 15, 2017. In approving the Investment Sub-Advisory Agreement, the Fund relied on an Exemptive Order issued by the Securities and Exchange Commission that permits the Fund and its investment adviser to hire or terminate a sub-adviser at any time without shareholder approval so long as, among other conditions, shareholders are provided notice of the change. As a result of this change, the Summary Prospectus shall be amended effective October 27, 2017 as noted below. The “PRINCIPAL INVESTMENT STRATEGIES” section is amended to read as follows:

“Normally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in equity securities of large capitalization companies. For this purpose, large capitalization equity investments are those whose market capitalizations are above $5 billion at the time of purchase. In managing the Portfolio, the adviser allocates the Portfolio’s assets across a variety of industries, selecting companies in each industry based on the research of a team of global industry analysts. The Portfolio typically seeks to maintain representation in each major industry represented by broad-based, large cap U.S. equity indices. In analyzing a prospective investment for the Portfolio, the adviser utilizes a “bottom-up” approach, which is the use of fundamental analysis to identify specific securities for purchase or sale. Fundamental analysis of a company involves the assessment of a variety of factors, including the company’s business environment, management quality, balance sheet, income statement, anticipated earnings, revenues and dividends, and other related measures or indicators of valuation and growth potential. The Portfolio’s sector exposures generally conform with the sector weights present in the Portfolio’s benchmark index and as a result, in combination with the Portfolio’s reliance on fundamental company analysis, and based upon market or economic conditions, the Portfolio may at times have a relatively high percentage of its assets invested in a particular sector of the market.

Page 14: The Northwestern Mutual Life Insurance Company VariableLife

Page 2 of 2

The Portfolio invests primarily in U.S. common stocks. Up to 20% of the Portfolio’s net assets may be invested in foreign based companies listed on foreign exchanges, either directly or through American Depositary Receipts (ADRs). The Portfolio may sell a security for a variety of reasons, including a significant adverse change in the company’s business fundamentals, if the company has become significantly overvalued in terms of earnings, assets or growth prospects, or more attractive alternatives exist.”

The “PERFORMANCE” section is amended by inserting the following as the third and fourth sentences of the first paragraph:

“Prior to October 27, 2017, the sub-adviser to the Portfolio was different. Performance shown may have been different if the current strategy, and the current sub-adviser, had been in place during the periods shown.”

The “PORTFOLIO MANAGEMENT” section is amended to read as follows:

“Investment Adviser: Mason Street Advisors, LLC (MSA) Sub-Adviser: Wellington Management Company LLP (Wellington Management) Portfolio Managers: Mark D. Mandel, CFA and Director of Global Industry Research, joined Wellington Management in 1995 and has co-managed the Portfolio since October 2017. Jonathan G. White, CFA and Director of Research Portfolios, joined Wellington Management in 1999 and has co-managed the Portfolio since October 2017.”

The Portfolio may experience increased portfolio turnover over the short term in connection with the transition to a new sub-adviser. Increased portfolio turnover can result in higher brokerage commissions and other transaction costs, which can adversely affect performance.

Please retain this Supplement for future reference.

Page 15: The Northwestern Mutual Life Insurance Company VariableLife

Page 1 of 2

Northwestern Mutual Series Fund, Inc. Mid Cap Growth Stock Portfolio

Supplement Dated September 27, 2017

to the Summary Prospectus for the Mid Cap Growth Stock Portfolio Dated May 1, 2017

The following information supplements the Summary Prospectus for the Mid Cap Growth Stock Portfolio of Northwestern Mutual Series Fund, Inc. (“Fund”) dated May 1, 2017 (the “Summary Prospectus”), a copy of which you have already received. You should read this Supplement together with the Summary Prospectus. Sub-Adviser Change On or about October 27, 2017, Wellington Management Company LLP (“Wellington Management”) will replace William Blair Investment Management, LLC as the sub-adviser for the Fund’s Mid Cap Growth Stock Portfolio (the “Portfolio”). Wellington Management will provide investment sub-advisory services for the Portfolio pursuant to an Investment Sub-Advisory Agreement approved by the Fund’s Board of Directors on August 15, 2017. In approving the Investment Sub-Advisory Agreement, the Fund relied on an Exemptive Order issued by the Securities and Exchange Commission that permits the Fund and its investment adviser to hire or terminate a sub-adviser at any time without shareholder approval so long as, among other conditions, shareholders are provided notice of the change. As a result of this change, the Summary Prospectus shall be amended effective October 27, 2017 as noted below. The “PRINCIPAL INVESTMENT STRATEGIES” section is amended to read as follows:

“Normally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in stocks of mid-sized companies. The Portfolio considers a company to be a mid-capitalization company if it has a market capitalization within the collective range of the Russell MidCap® Index and the S&P MidCap 400® Index. As of June 30, 2017, this range was approximately $1.2 billion to $47.2 billion. The market capitalization range of these indices changes over time. Securities of companies whose market capitalizations no longer fall within this collective range after purchase may continue to be held by the Portfolio. The Portfolio invests primarily in common stocks of mid cap companies selected on the basis of their potential for capital appreciation. The Portfolio focuses on companies that are determined to be of high quality. The key characteristics of high quality companies include a leadership position within an industry, a strong balance sheet, a high return on equity, and/or a strong management team. The Portfolio seeks to reduce overall risk by diversifying across sectors, industry groups and companies. The Portfolio’s sector exposure relative to its benchmark is driven by an investment process which relies on fundamental company analysis and individual stock selection. As a result, based upon market or economic conditions, the Portfolio may at times have a relatively high percentage of its assets invested in a particular sector of the market.

Page 16: The Northwestern Mutual Life Insurance Company VariableLife

Page 2 of 2

The Portfolio invests primarily in U.S. common stocks. The Portfolio may also invest up to 20% of net assets in American Depositary Receipts (ADRs) and other securities of foreign issuers, including non-U.S. dollar denominated securities. The Portfolio typically trims positions as valuation appears incrementally less attractive, and may sell a stock when the adviser’s investment thesis is no longer valid, typically due to an erosion of company fundamentals relative to expectations or when valuation is no longer attractive. The Portfolio may, but is not required to, exit a position if the company’s capitalization grows beyond the mid cap range.”

The “PRINCIPAL RISKS” section is amended by adding the following “Foreign Currency Risk” factor:

“▪ Foreign Currency Risk – The risk that foreign (non-U.S. dollar) currency denominated securities may be adversely affected by decreases in foreign currency values relative to the U.S. dollar. Investments in securities subject to foreign currency risk may have more rapid and extreme changes in value or more losses than investments in U.S. dollar denominated securities.”

The “PERFORMANCE” section is amended by inserting the following as the third and fourth sentences of the first paragraph:

“Prior to October 27, 2017, the sub-adviser to the Portfolio was different. Performance shown may have been different if the current strategy, and the current sub-adviser, had been in place during the periods shown.”

The “PORTFOLIO MANAGEMENT” section is amended to read as follows:

“Investment Adviser: Mason Street Advisors, LLC (MSA) Sub-Adviser: Wellington Management Company LLP (Wellington Management) Portfolio Managers: Philip W. Ruedi, CFA, Senior Managing Director and Equity Portfolio Manager, joined Wellington Management in 2004 and has co-managed the Portfolio since October 2017. Mark Whitaker, CFA, Senior Managing Director and Equity Portfolio Manager, joined Wellington Management in 2004 and has co-managed the Portfolio since October 2017.”

The Portfolio may experience increased portfolio turnover over the short term in connection with the transition to a new sub-adviser. Increased portfolio turnover can result in higher brokerage commissions and other transaction costs, which can adversely affect performance.

Please retain this Supplement for future reference.

Page 17: The Northwestern Mutual Life Insurance Company VariableLife

THE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY

SUPPLEMENT TO THE PROSPECTUSES (MAY 1, 2017) ________________________________________________________

NORTHWESTERN MUTUAL VARIABLE LIFE ACCOUNT

VARIABLE LIFE VARIABLE COMPLIFE® VARIABLE JOINT LIFE

VARIABLE EXECUTIVE LIFE ________________________________________________________

NORTHWESTERN MUTUAL VARIABLE LIFE ACCOUNT II

CUSTOM VARIABLE UNIVERSAL LIFE EXECUTIVE VARIABLE UNIVERSAL LIFE

SURVIVORSHIP VARIABLE UNIVERSAL LIFE ________________________________________________________

This Supplement amends certain information contained in the Prospectuses referenced above. 1. On or about October 27, 2017, in the section titled, “The Funds – Northwestern Mutual Series

Fund, Inc.”, the following table is amended to contain the following information for the Mid Cap Growth Stock Portfolio and the Large Cap Core Stock Portfolio:

Portfolio Investment Objective Sub-adviser (if applicable)

Mid Cap Growth Stock Portfolio Long-term growth of capital Wellington Management Company LLP

Large Cap Core Stock Portfolio Long-term growth of capital and income

Wellington Management Company LLP

Please read this Supplement carefully and keep it with your Prospectus for future reference.

This Supplement is dated August 21, 2017.

Page 18: The Northwestern Mutual Life Insurance Company VariableLife

Northwestern Mutual Series Fund, Inc. Prospectus Supplement Dated August 18, 2017

The following information supplements the Statutory Prospectus for the Northwestern Mutual Series Fund, Inc. (the “Fund”) dated May 1, 2017, as supplemented May 24, 2017 (the “Prospectus”). You should read this Supplement together with the Prospectus. Sub-Adviser Changes for Mid Cap Growth Stock and Large Cap Core Stock Portfolios On or about October 27, 2017, Wellington Management Company LLP (“Wellington Management”) will replace William Blair Investment Management, LLC as the sub-adviser for the Fund’s Mid Cap Growth Stock Portfolio and will also replace Fayez Sarofim & Co. as the sub-adviser for the Fund’s Large Cap Core Stock Portfolio. Wellington Management will provide investment sub-advisory services for the Portfolios pursuant to Investment Sub-Advisory Agreements approved by the Fund’s Board of Directors on August 15, 2017. In approving the new Investment Sub-Advisory Agreements, the Fund relied on an Exemptive Order issued by the Securities and Exchange Commission that permits the Fund and its investment adviser to hire or terminate a sub-adviser at any time without shareholder approval so long as, among other conditions, shareholders are provided notice of the change. Additional information about Wellington Management, its investment strategies for the Portfolios, associated risks, and other information will be made available in the coming months consistent with the requirements of the Exemptive Order.

Please retain this Supplement for future reference.

 

Page 19: The Northwestern Mutual Life Insurance Company VariableLife

Northwestern Mutual Series Fund, Inc. Prospectus Supplement Dated May 24, 2017

The following information supplements the Statutory Prospectus for the Northwestern Mutual Series Fund, Inc. (the “Fund”) dated May 1, 2017 (the “Prospectus”). You should read this Supplement together with the Prospectus. Amendments to Investment Sub-Advisory Agreements with Certain Sub-Advisers

Effective February 22, 2017, the Board of Directors of the Fund approved amended and restated investment sub-advisory agreements between Mason Street Advisors, LLC (“Mason Street Advisors”) and (i) The Boston Company Asset Management, LLC (“The Boston Company”) with respect to the Growth Stock Portfolio; (ii) William Blair Investment Management, LLC (“William Blair”) with respect to the Mid Cap Growth Stock Portfolio; and (iii) Wellington Management Company LLP (“Wellington”) with respect to the Small Cap Growth Portfolio. Effective May 10, 2017, the Board of Directors of the Fund approved amended and restated investment sub-advisory agreements between Mason Street Advisors and (i) Fayez Sarofim & Co. (“Sarofim & Co.”) with respect to the Large Cap Core Stock Portfolio; (ii) FIAM LLC (“FIAM”) with respect to the International Growth Portfolio; (iii) Fiduciary Management, Inc. (“FMI”) with respect to the Large Cap Blend Portfolio; (iv) Massachusetts Financial Services Company (“MFS”) with respect to the Research International Core Portfolio; and (v) Templeton Investment Counsel, LLC (“Templeton”) with respect to the International Equity Portfolio. In approving the foregoing amended and restated investment sub-advisory agreements (the “Amended Agreements”), the Fund relied on an Exemptive Order issued by the Securities and Exchange Commission that permits the Fund and Mason Street Advisors to amend investment sub-advisory agreements without shareholder approval so long as, among other conditions, shareholders are provided notice of the amendment. The Amended Agreements, which conform the existing agreements with The Boston Company, William Blair, Wellington, Sarofim & Co., FIAM, FMI, MFS and Templeton to Mason Street Advisors’ current form of Investment Sub-Advisory Agreement, include updated provisions reflecting developments in the investment management industry and memorializing certain business practices in place between Mason Street Advisors and its sub-advisers. The Amended Agreements include certain reporting and monitoring obligations applicable to investments in commodity interests, particularly involving derivatives transactions. The Amended Agreements also set forth the sub-advisers’ responsibilities regarding the establishment and implementation of a reasonably-designed cybersecurity program and associated policies. Except for a modification regarding the fee schedule applicable to the Large Cap Blend Portfolio managed by FMI, the Amended Agreements did not include any changes to fees.

Please retain this Supplement for future reference.

 

Page 20: The Northwestern Mutual Life Insurance Company VariableLife

Table of Contents

Variable Product Prospectus

Page LabelVariable Life 1

Summary Prospectuses

Northwestern Mutual Series Fund, Inc. Page LabelGrowth Stock Portfolio NMSF-1Focused Appreciation Portfolio NMSF-4Large Cap Core Stock Portfolio NMSF-7Large Cap Blend Portfolio NMSF-10Index 500 Stock Portfolio NMSF-13Large Company Value Portfolio NMSF-16Domestic Equity Portfolio NMSF-19Equity Income Portfolio NMSF-22Mid Cap Growth Stock Portfolio NMSF-25Index 400 Stock Portfolio NMSF-28Mid Cap Value Portfolio NMSF-31Small Cap Growth Stock Portfolio NMSF-34Index 600 Stock Portfolio NMSF-38Small Cap Value Portfolio NMSF-41International Growth Portfolio NMSF-45Research International Core Portfolio NMSF-48International Equity Portfolio NMSF-52Emerging Markets Equity Portfolio NMSF-55Government Money Market Portfolio NMSF-59Short-Term Bond Portfolio NMSF-62Select Bond Portfolio NMSF-66Long-Term U.S. Government Bond Portfolio NMSF-69Inflation Protection Portfolio NMSF-73High Yield Bond Portfolio NMSF-77Multi-Sector Bond Portfolio NMSF-80Balanced Portfolio NMSF-85Asset Allocation Portfolio NMSF-90

Fidelity® Variable Insurance Products Page LabelVIP Mid Cap Portfolio FI-1VIP Contrafund® Portfolio FI-7

Neuberger Berman Advisers Management Trust Page LabelSocially Responsive Portfolio NB-1

Russell Investment Funds Page LabelU.S. Strategic Equity Fund RIF-1U.S. Small Cap Equity Fund RIF-7Global Real Estate Securities Fund RIF-13International Developed Markets Fund RIF-19Strategic Bond Fund RIF-25

Russell Investment Funds LifePoints® Variable Target Portfolio Series Page LabelModerate Strategy Fund RLP-1Balanced Strategy Fund RLP-9Growth Strategy Fund RLP-17Equity Growth Strategy Fund RLP-25

Credit Suisse Trust Page LabelCommodity Return Strategy Portfolio CST-1

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P r o s p e c t u sMay 1, 2017

Variable LifeWhole Life

Extra Ordinary LifeSingle Premium Life

Issued by The Northwestern Mutual Life Insurance Companyand the Northwestern Mutual Variable Life Account

This prospectus describes three Variable Life Insurance Policies (each a “Policy”, together the “Policies”). You may chooseto invest your Net Premiums in up to six Divisions of the Northwestern Mutual Variable Life Account (the “SeparateAccount”), each of which invests in one of the corresponding Portfolios listed below:

Northwestern Mutual Series Fund, Inc.Growth Stock PortfolioFocused Appreciation PortfolioLarge Cap Core Stock PortfolioLarge Cap Blend PortfolioIndex 500 Stock PortfolioLarge Company Value PortfolioDomestic Equity PortfolioEquity Income PortfolioMid Cap Growth Stock PortfolioIndex 400 Stock PortfolioMid Cap Value PortfolioSmall Cap Growth Stock PortfolioIndex 600 Stock PortfolioSmall Cap Value PortfolioInternational Growth PortfolioResearch International Core PortfolioInternational Equity PortfolioEmerging Markets Equity PortfolioGovernment Money Market PortfolioShort-Term Bond PortfolioSelect Bond PortfolioLong-Term U.S. Government Bond PortfolioInflation Protection PortfolioHigh Yield Bond PortfolioMulti-Sector Bond PortfolioBalanced PortfolioAsset Allocation Portfolio

Fidelity® Variable Insurance ProductsVIP Mid Cap PortfolioVIP Contrafund® Portfolio

Neuberger Berman Advisers Management TrustSocially Responsive Portfolio

Russell Investment FundsU.S. Strategic Equity FundU.S. Small Cap Equity FundGlobal Real Estate Securities FundInternational Developed Markets FundStrategic Bond Fund

Russell Investment Funds LifePoints®Variable Target Portfolio SeriesModerate Strategy FundBalanced Strategy FundGrowth Strategy FundEquity Growth Strategy Fund

Credit Suisse TrustCommodity Return Strategy Portfolio

Please note that the Policies and the Portfolios are not guaranteed to achieve their goals and are not federally insured.The Policies and the Portfolios have not been endorsed by any bank or government agency and are subject to risks,

including loss of the principal amount invested.Each Policy is subject to the law of the state in which it is issued. Some of the terms of a Policy may differ from the terms ofa Policy delivered in another state because of state specific legal requirements. Areas where state specific Policy provisionsmay apply include, but are not limited to:

• certain investment options and certain policy features; and• portfolio transfer rights.

Please read carefully this prospectus and the accompanying prospectuses for the corresponding Portfolios and keep themfor future reference. These prospectuses provide information that you should know before investing in the Policies. No

person is authorized to make any representation in connection with the offering of the Policies other than thosecontained in these prospectuses.

The Securities and Exchange Commission (“SEC”) has not approved or disapproved the Policies or determined that thisprospectus is accurate or complete. It is a criminal offense to state otherwise.

We no longer issue the three Policies described in this prospectus. The variable life policies we presently offer aredescribed in separate prospectuses.

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Contents for this ProspectusPage

SUMMARY OF BENEFITS AND RISKS . . . . . . . 1Benefits of the Policies . . . . . . . . . . . . . . . . . . . . 1Death Benefit . . . . . . . . . . . . . . . . . . . . . . . . . . 1Access to Your Values . . . . . . . . . . . . . . . . . . . 1Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Optional Benefits . . . . . . . . . . . . . . . . . . . . . . . 1Income Plan Options . . . . . . . . . . . . . . . . . . . . 1Tax Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Risks of the Policies . . . . . . . . . . . . . . . . . . . . . . . 1Investment Risk . . . . . . . . . . . . . . . . . . . . . . . . 1Default Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Policy for Long-Term Protection . . . . . . . . . . . 1Policy Lapse . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Policy Loan Risks . . . . . . . . . . . . . . . . . . . . . . 2Limitations on Access to Your Values . . . . . . 2Adverse Tax Consequences . . . . . . . . . . . . . . . 2Risk of an Increase in Current Fees andExpenses . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

FEE AND EXPENSE TABLES . . . . . . . . . . . . . . . 2Transaction Fees . . . . . . . . . . . . . . . . . . . . . . . . . 2Periodic Charges (Other than PortfolioOperating Expenses) . . . . . . . . . . . . . . . . . . . . 3Whole Life Policy . . . . . . . . . . . . . . . . . . . . . . 3Extra Ordinary Life Policy . . . . . . . . . . . . . . . 4Single Premium Life Policy . . . . . . . . . . . . . . . 6

Annual Portfolio Operating Expenses . . . . . . . . . 6THE COMPANY . . . . . . . . . . . . . . . . . . . . . . . . . . . 6THE SEPARATE ACCOUNT . . . . . . . . . . . . . . . . 7THE FUNDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Northwestern Mutual Series Fund, Inc. (the“Series Fund”) . . . . . . . . . . . . . . . . . . . . . . . . . 8

Fidelity® Variable Insurance Products . . . . . . . . 9Neuberger Berman Advisers ManagementTrust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Russell Investment Funds . . . . . . . . . . . . . . . . . . 10Credit Suisse Trust . . . . . . . . . . . . . . . . . . . . . . . . 10Payments We Receive . . . . . . . . . . . . . . . . . . . . . 10

INFORMATION ABOUT THE POLICIES . . . . . . 11Premiums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Whole Life Policy . . . . . . . . . . . . . . . . . . . . . . 11Extra Ordinary Life Policy . . . . . . . . . . . . . . . 12Single Premium Life Policy . . . . . . . . . . . . . . . 12

Grace Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Allocating Premiums to the Separate Account . . 12Transfers Between Divisions . . . . . . . . . . . . . . 13Short-Term and Excessive Trading . . . . . . . . . 13

Deductions and Charges . . . . . . . . . . . . . . . . . . . 14Deductions from Premiums for Whole Lifeand Extra Ordinary Life Policies . . . . . . . . . 15

Deductions for Single Premium Life Policies . . . 16Charges Against the Separate AccountAssets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Optional Benefits . . . . . . . . . . . . . . . . . . . . . . . 16

Page

Guarantee of Premiums, Deductions andCharges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Death Benefit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Variable Insurance Amount . . . . . . . . . . . . . . . 17Whole Life Policy and Single Premium LifePolicy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Extra Ordinary Life Policy . . . . . . . . . . . . . . . 18Cash Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Annual Dividends . . . . . . . . . . . . . . . . . . . . . . . . 20Policy Loans and Automatic Premium Loans . . . 20Policy Loans . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Automatic Premium Loans . . . . . . . . . . . . . . . 20General Loan Terms . . . . . . . . . . . . . . . . . . . . 20

Extended Term and Paid-Up Insurance . . . . . . . . 21Reinstatement . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Reinvestments After Surrender . . . . . . . . . . . . . . 22Right to Exchange for a Fixed Benefit Policy . . . 22Modifying a Policy . . . . . . . . . . . . . . . . . . . . . . . 22Other Policy Provisions . . . . . . . . . . . . . . . . . . . . 23Owner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Beneficiary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Incontestability . . . . . . . . . . . . . . . . . . . . . . . . . 23Misstatement of Age or Sex . . . . . . . . . . . . . . . 23Collateral Assignment . . . . . . . . . . . . . . . . . . . 23Optional Benefits . . . . . . . . . . . . . . . . . . . . . . . 23Income Plans . . . . . . . . . . . . . . . . . . . . . . . . . . 23Deferral of Determination and Payment . . . . . 23

Voting Rights . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Substitution of Portfolio Shares and Other

Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Reports and Financial Statements . . . . . . . . . . . . 24Special Policy for Employers . . . . . . . . . . . . . . . 24Householding . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Abandoned Property Requirements . . . . . . . . . . . 24Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Legal Proceedings . . . . . . . . . . . . . . . . . . . . . . . . 24Speculative Investing . . . . . . . . . . . . . . . . . . . . . . 25Owner Inquiries . . . . . . . . . . . . . . . . . . . . . . . . . . 25Illustrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

TAX CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 25General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Life Insurance Qualification . . . . . . . . . . . . . . 25Tax Treatment of Life Insurance . . . . . . . . . . . 26Modified Endowment Contracts (MEC) . . . . . 27Estate and Generation Skipping Taxes . . . . . . 27Business-Owned Life Insurance . . . . . . . . . . . 28Policy Split Right . . . . . . . . . . . . . . . . . . . . . . . 28Split Dollar Arrangements . . . . . . . . . . . . . . . . 28Valuation of Life Insurance . . . . . . . . . . . . . . . 29Other Tax Considerations . . . . . . . . . . . . . . . . 29

DISTRIBUTION OF THE POLICY . . . . . . . . . . . . 29GLOSSARY OF TERMS . . . . . . . . . . . . . . . . . . . . 30ADDITIONAL INFORMATION . . . . . . . . . . . . . . 32

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Variable Life• Whole Life• Extra Ordinary Life• Single Premium Life

Summary of Benefits and RisksThe following summary identifies some of the benefits andrisks of the three Policies described in this prospectus. It omitsimportant information which is included elsewhere in thisprospectus, in the attached mutual fund prospectuses, and inthe terms of the Policies. Unless clear from their context orotherwise appropriate, all of the capitalized terms used in thisprospectus are defined herein or at the end of this prospectusin the Glossary of Terms.

Benefits of the Policies

Death Benefit The primary benefit of each Policy is the lifeinsurance protection that it provides. For each Policy theDeath Benefit includes a guaranteed amount which will not bereduced during the lifetime of the Insured so long as you paypremiums when they are due and no Policy Debt isoutstanding. The remainder of the Death Benefit is thevariable insurance amount which fluctuates in response toactual investment results and is not guaranteed. The ExtraOrdinary Life Policy also provides some term insuranceduring the early Policy Years. The Death Benefit is increasedby the amount of any paid-up additions which you havepurchased with any dividends that we pay, except that forExtra Ordinary Life Policies, variable insurance amount andpaid-up additions will first be used to replace term insurancebefore increasing the Death Benefit. The relationships amongthe guaranteed and variable amounts and any paid-upadditions and term insurance depend on the design of theparticular Policy.

Access to Your Values The Policy provides access to CashValue during the lifetime of the Insured. You may surrenderyour Policy for the Cash Value at any time during the lifetimeof the Insured. We will permit a Death Benefit reduction solong as the Policy that remains meets our minimum sizerequirements. Under some circumstances there may be arelease of Cash Value upon the reduction of your DeathBenefit. You may borrow up to 90% of your Policy’s CashValue using the Policy as security.

Flexibility You may direct the allocation of your premiumsand apportion the Separate Account assets supporting yourPolicy among the various Divisions of the Separate Account,using as many as six Divisions at any time. Subject to certainlimits, you may transfer accumulated amounts from oneDivision to another as often as four times in a Policy Year.

Optional Benefits Whole Life and Extra Ordinary LifePolicies may include two optional benefits: a Waiver ofPremium Benefit and an Additional Purchase Benefit. These

optional benefits are not available for all Issue Ages andunderwriting classifications, and may not be available in allstates.

Income Plan Options There are several ways of receivingproceeds under the Death Benefit and surrender provisions ofthe Policy, other than in a lump sum. More detailedinformation concerning these options is included elsewhere inthis prospectus. You may also call our Income and MaturityServices Department at 1-866-269-2950 for more information.

Tax Benefits You are generally not taxed on your Policy’sinvestment gains until you surrender the Policy.

Risks of the Policies

Investment Risk Your Policy allows you to participate inthe investment experience of the Divisions you select. Youbear the corresponding investment risks. You will be subjectto the risk that the investment performance of the Divisionswill be unfavorable and that, due both to the unfavorableperformance and the resulting higher insurance charges, thePolicy Value and Cash Value will decrease. You could loseeverything you invest. You may find a comprehensivediscussion of these investment risks in the attached mutualfund prospectuses. You will also be subject to the risk that theinvestment performance of the Divisions you choose may beless favorable than that of other Divisions, and in order tokeep the Extra Life Protection of an Extra Ordinary LifePolicy from decreasing, you may be required to pay morepremiums than originally planned.

Default Risk Because certain guarantees under the Policiesare guaranteed by the Company’s General Account assets, theability to make good on these guarantees depends on thefinancial strength and claims-paying ability of the Company.Therefore, guaranteed benefits in excess of Invested Assets inthe Separate Account are subject to the risk of default to theextent the Company is unable to satisfy some or all of theseguarantees.

Policy for Long-Term Protection Your Policy is designedto serve your need for long-term life insurance protection. It isnot a suitable investment for short-term goals. We have notdesigned the Policies for frequent trading.

Policy Lapse Your Whole Life or Extra Ordinary LifePolicy will lapse unless you pay the premiums when they aredue, unless the Policy is continued as extended term insuranceor a reduced amount of paid-up insurance.

Variable Life Prospectus 1

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Policy Loan Risks A loan, whether or not repaid, will affectyour Policy Value and Cash Value over time because theamounts borrowed do not participate in the investmentperformance of the Divisions; in addition, a charge isdeducted from your Policy Value while there is Policy Debt.The effect of a loan may be either favorable or unfavorable,depending on whether the earnings rate credited to the loanamount is higher or lower than the investment performance ofthe unborrowed amounts left in the Divisions. The DeathBenefit is reduced by the amount of any Policy Debtoutstanding. If you surrender the Policy or allow it to lapsewhile Policy Debt is outstanding, the amount of the loan, tothe extent it has not previously been taxed, will be consideredas an amount you received and taxed accordingly.

Limitations on Access to Your Values The Policies permitaccess to Cash Value by Policy loans and by surrender of thePolicy. A partial withdrawal of the Cash Value is notpermitted, except to the extent there is a reduction of DeathBenefit which leads to a release of Cash Value.

Adverse Tax Consequences Our understanding of theprincipal tax considerations for the Policy under current taxlaw is set forth in this prospectus. There are areas of someuncertainty under current law, and we do not address thelikelihood of future changes in the law or interpretationsthereof. Among other risks, your Policy may become a

modified endowment contract. A modified endowmentcontract (“MEC”) is a life insurance contract that is taxed lessfavorably on lifetime distributions than other life insurancecontracts because the contract is considered too investmentoriented. Generally, a Policy may be classified as a MEC ifcumulative premiums paid during a seven-pay period exceed a“seven-pay” limit defined in the Internal Revenue Code.Distributions, including loans, from a Policy classified as aMEC are taxable to the extent of the gain in the Policy andmay be subject to a 10% premature withdrawal penalty iftaken before the Owner attains age 591⁄2. Moreover, excessivePolicy loans could cause a Policy to terminate with no valuewith which to pay the tax liability. In addition, please note thatyou may no longer change Insureds on your Policy, unless youexchange your Policy for a new Policy with mortality tablesrecognized by the Internal Revenue Service when satisfyingthe definitional test for life insurance. Death Benefit proceedsmay be subject to state and/or inheritance taxes. (See “TaxConsiderations”).

Risk of an Increase in Current Fees and Expenses Certainfees and expenses are currently assessed at less than theirmaximum levels. We may increase these current charges inthe future up to the guaranteed maximum levels. If fees andexpenses are increased, you may need to increase the amountof premiums to keep the Extra Life Protection of an ExtraOrdinary Life Policy from decreasing.

Fee and Expense TablesThe following tables describe the fees and expenses that you will pay when owning or surrendering a Policy. See “Deductionsand Charges” for a more detailed description.

Transaction Fees1

This table describes the fees and expenses you will pay when you pay premiums, surrender the Policy or transfer amountsbetween the Divisions.

Charge When Charge is Deducted Current Amount Deducted Maximum Amount Deducted

Whole Life andExtra Ordinary LifePolicies

Premium Taxes When you paypremiums

2% of the basic premium2 2% of the basic premium2

Sales Load When you paypremiums

Year 1: 30% of basicpremium2

Years 2-4: 10% of basicpremium2

Years 5-on: Not more than7% of basic premium2

Same as the current amount

Charge for IssuanceExpenses

When you paypremiums—firstPolicy Year only

Not more than $5 for each$1,000 of insurance

Same as the current amount

Single Premium LifePolicy

AdministrativeCharge

When we issue thePolicy

$150 $150

Surrender Charge When you surrenderthe Policy during thefirst ten PolicyYears

0% Not more than 9% of thepremium paid for thePolicy3

All PoliciesFee for Transfer ofAssets

When you transferassets among theDivisions

Currently waived The fee will not exceed ouradministrative costs oftransfers

2 Variable Life Prospectus

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Charge When Charge is Deducted Current Amount Deducted Maximum Amount Deducted

Whole Life and ExtraOrdinary LifePolicies

Extra Premium forInsureds Who Do NotQualify as Select Risks

When you paypremiums

The amount depends on theunderwriting classification

Same as current amount4;Variable Whole Life;

Maximum: $52.70 per$1,000 of face amount;

Variable Extra OrdinaryLife Policies;

Maximum: $58.71 per$1,000 of face amount

All Policies

Expedited DeliveryCharge5

When express maildelivery is requested

$15 per delivery (up to $45for next day, a.m. delivery)

$50 per delivery (up to $75for next day, a.m. delivery)adjusted for inflation6

Wire Transfer Fee5 When a wire transferis requested

$25 per transfer (up to $50for international wires)

$50 per transfer (up to $100for international wires)adjusted for inflation6

1 Some fees and expenses, such as fees applicable in Policy Years prior to your current Policy Year, may no longer apply because the Policies are no longerissued.

2 The basic premium for a Policy is the gross premium which would be payable if you paid the premium annually, less the annual deduction for administrativecosts. See “Deductions and Charges” for more information.

3 This charge no longer applies because you have owned your Policy for longer than ten years.4 This charge will vary depending on underwriting classification of the Insured.5 This fee may increase over time to cover our administrative or other costs but will not exceed the maximum charge. We may discontinue this service at any

time, with or without notice.6 The maximum amount deducted is subject to a consumer price index adjustment in order to accommodate future increases in the costs associated with these

requests. The maximum amount deducted will equal the maximum charge shown above multiplied by the CPI for the fourth month prior to the time of thecharge, divided by the CPI for April, 2009. “CPI” means the Consumer Price Index for All Urban Consumers, United States City Average, All Items, aspublished by the United States Bureau of Labor Statistics. If the method for determining the CPI is changed, or it is no longer published, it will be replaced bysome other index found by the Company to serve the same purpose.

Periodic Charges (Other than Portfolio Operating Expenses)

These tables describe the fees and expenses, other than operating expenses for the Portfolios, that you will pay periodically duringthe time that you own a Policy. Please refer to the table specific to your Policy. As noted below, in some cases the charges shownin the table may not be representative of what a particular Owner may pay. Please request an illustration from your FinancialRepresentative for personalized information, including the particular charges applicable to your Policy. (See “Illustrations”).

Whole Life Policy

Charge When Charge is Deducted Current Amount Deducted Maximum Amount Deducted

Charge forAdministrative Costs

Annually, on the PolicyAnniversary

$35 $35

Charge for DeathBenefit Guarantee

Annually, on the PolicyAnniversary

11⁄2% of the basic premium1 11⁄2% of the basic premium1

Charge for Mortalityand Expense Risks

Daily Annual rate of .50% of the Separate Account Assets Annual rate of .50% of theSeparate Account Assets

Charge for FederalIncome Taxes

Daily Annual rate of .05% of the Separate Account Assets A rate which reflects thatportion of our actual taxexpenses which is fairlyallocable to the Policies

Cost of Insurance Calculated at leastannually on the PolicyAnniversary

Maximum: $1,000 per $1,000 of net amount at risk(Attained Age 99)2

Minimum: $0.69 per $1,000 of net amount at risk(Attained Age 10 female)2

Representative: $10.47 per $1,000 of net amount atrisk (Attained Age 55 male)

Same as current amount,without the current dividend

Charge for Mortalityand Expense Risksand Expenses forLoans3

Daily Annual rate of .85% of the borrowed amount Annual rate of 1.00% of theborrowed amount

Variable Life Prospectus 3

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Charge When Charge is Deducted Current Amount Deducted Maximum Amount Deducted

Waiver of PremiumBenefit4

Annually, on the PolicyAnniversary, if thisbenefit is attached to yourPolicy and the AttainedAge is less than 65

Maximum: $2.05 per $1,000 of face amount(Issue Age 58)

Minimum: $0.13 per $1,000 of face amount(Issue Age 0-6)

Representative: $0.37 per $1,000 of face amount(Issue Age 35)

Same as current amount

Additional PurchaseBenefit5

Annually, on the PolicyAnniversary, if thisbenefit is attached to yourPolicy and the AttainedAge is lessthan 40

Maximum: $2.21 per $1,000 of Additional PurchaseBenefit (Issue Age 38)5

Minimum: $0.54 per $1,000 of Additional PurchaseBenefit (Issue Age 0)5

Representative: $0.54 per $1,000 of AdditionalPurchase Benefit (Issue Age 0)

Same as current amount

1 The basic premium for a Policy is the gross premium which would be payable if you paid the premium annually, less the annual deduction for administrativecosts. See “Deductions and Charges” for more information.

2 The Policy includes no provisions for explicit deductions or charges for the cost of insurance, but this cost is reflected in the table of Cash Values at the frontof the Policy and in the table of net single premiums we use to determine the variable insurance amount. The variable insurance amount is used to calculateboth the Death Benefit and the Cash Value. The cost of insurance is based on factors including but not limited to the Insured’s Attained Age, the 1980 CSOMortality Table and the net insurance amount at risk. The net insurance amount at risk is the Death Benefit minus the sum of the Cash Value and any PolicyDebt. The rates shown in the table may not be representative of the charge a particular Owner may pay. The amount you pay for the cost of insurance iseffectively reduced by the dividends, if any, we currently pay on your Policy. You may ask your Financial Representative for the current dividend amount.Future dividends are not guaranteed. (See “Annual Dividends”).

3 The charge is applied to the Policy Debt. The charge shown is a loan interest spread that is deducted from the Invested Assets. We add unpaid interest to theamount of the loan. Interest on a Policy loan accrues and is payable on a daily basis at an annual effective rate of 8% or an alternative variable rate based on abond yield index. The amount of the Policy loan will be transferred from the Divisions to our General Account and credited on a daily basis with an annualearnings rate equal to the Policy loan interest rate less the charge shown.

4 The charges shown in the table may not be representative of the charge that a particular Owner may pay. The charge does not vary by sex. Generally, thecharge increases for older Issue Ages. In addition, higher rates may apply to substandard underwriting classifications. The charge for the Waiver of PremiumBenefit is less for Extra Ordinary Life Policies than for Whole Life Policies, all other factors being equal.

5 The maximum benefit amount is $100,000. The charges shown in the table may not be representative of the charge that a particular Owner may pay. Thecharge does not vary by sex. The charge increases for older Issue Ages.

Extra Ordinary Life PolicyCharge When Charge is Deducted Current Amount Deducted Maximum Amount Deducted

Charge for Mortalityand Expense Risks

Daily Annual rate of .50% of the Separate Account Assets Annual rate of .50% of theSeparate Account Assets

Charge for FederalIncome Taxes

Daily Annual rate of .05% of the Separate Account Assets A rate which reflects thatportion of our actual taxexpenses which is fairlyallocable to the Policies

Cost of Insurance Calculated at leastannually on the PolicyAnniversary

Maximum: $1,000 per $1,000 of net amount at risk(Attained Age 99)1

Minimum: $0.85 per $1,000 of net amount at risk(Attained Age 15 female)1

Representative: $16.08 per $1,000 of net amount atrisk (Attained Age 60 male)

Same as current amount,without the current dividend

Charge for Mortalityand Expense Risksand Expenses forLoans2

Daily Annual rate of .85% of the borrowed amount Annual rate of 1.00% of theborrowed amount

Charge for Dividends3 Annually, on the PolicyAnniversary

Maximum: 17% of the gross annual premium4 Same as current amount

Extra Premium forExtra Life Protection(after the expiry of theguaranteed period)

Annually, after the expiryof the guaranteed period,on the PolicyAnniversary5

Maximum: $283.64 per $1,000 of term insurance6

(Attained Age 99 male standard)

Minimum: $1.93 per $1,000 of term insurance6

(Attained Age 52 female select)

Representative: $5.11 per $1,000 of term insurance6

(Attained Age 62 male select)

Maximum: $1,000 per$1,000 of term insurance,without the current dividend

Minimum: $6.27 per $1,000of term insurance, withoutthe current dividend

4 Variable Life Prospectus

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Charge When Charge is Deducted Current Amount Deducted Maximum Amount Deducted

Charge forAdministrative Costs

Annually, on the PolicyAnniversary

$35 $35

Charge for DeathBenefit Guarantee

Annually, on the PolicyAnniversary

11⁄2% of the basic premium7 11⁄2% of the basic premium7

Waiver of PremiumBenefit8

Annually, on the PolicyAnniversary, if thisbenefit is attached to yourPolicy and the AttainedAge is less than 65

Maximum: $1.48 per $1,000 of face amount(Issue Age 48)

Minimum: $0.10 per $1,000 of face amount(Issue Age 15)

Representative: $0.24 per $1,000 of face amount(Issue Age 35)

Same as current amount

Additional PurchaseBenefit9

Annually, on the PolicyAnniversary, if thisbenefit is attached to yourPolicy and the AttainedAge is less than 40

Maximum: $2.21 per $1,000 of Additional PurchaseBenefit (Issue Age 38)9

Minimum: $1.06 per $1,000 of Additional PurchaseBenefit (Issue Age 15)9

Representative: $1.33 per $1,000 of AdditionalPurchase Benefit (Issue Age 25)9

Same as current amount

1 The Policy includes no provisions for explicit deductions or charges for the cost of insurance, but this cost is reflected in the table of Cash Values at the frontof the Policy and in the table of net single premiums we use to determine the variable insurance amount. The variable insurance amount is used to calculateboth the Death Benefit and the Cash Value. The cost of insurance is based on factors including but not limited to the Insured’s Attained Age, the 1980 CSOMortality Table and the net insurance amount at risk. The net insurance amount at risk is the Death Benefit minus the sum of the Cash Value and any PolicyDebt. The rates shown in the table may not be representative of the charge a particular Owner may pay. The amount you pay for the cost of insurance iseffectively reduced by the dividends, if any, we currently pay on your Policy. You may ask your Financial Representative for the current dividend amount.Future dividends are not guaranteed. (See “Annual Dividends”).

2 The charge is applied to the Policy Debt. The charge shown is a loan interest spread that is deducted from the Invested Assets. We add unpaid interest to theamount of the loan. Interest on a Policy loan accrues and is payable on a daily basis at an annual effective rate of 8% or an alternative variable rate based on abond yield index. The amount of the Policy loan will be transferred from the Divisions to our General Account and credited on a daily basis with an annualearnings rate equal to the Policy loan interest rate less the charge shown.

3 This charge will vary by Issue Age of the Insured.4 The charge for dividends is approximately 7% to 17% of the gross annual premium.5 After the guaranteed period expires, if the sum of positive variable insurance amount plus the paid-up additions is less than the initial amount of Extra Life

Protection, we may reduce the amount of term insurance for the Policy Year. Alternatively, you may choose to have the coverage maintained by paying alarger premium based on the term insurance rates described here. Your right to continue to purchase term insurance on this basis will terminate as of the firstPolicy Anniversary when you fail to pay the additional premium when due.

6 Estimated year-end dividends have the effect of reducing the term insurance amounts on which the charges are based.7 The basic premium for a Policy is the gross premium which would be payable if you paid the premium annually, less the annual deduction for administrative

costs. See “Deductions and Charges” for more information.8 The charges shown in the table may not be representative of the charge that a particular Owner may pay. The charge does not vary by sex. Generally, the

charge increases for older Issue Ages. In addition, higher rates may apply to substandard underwriting classifications. The charge for the Waiver of Premiumbenefit is less for Extra Ordinary Life Policies than for Whole Life Policies, all other factors being equal.

9 The maximum benefit amount is $100,000. The charges shown in the table may not be representative of the charge that a particular Owner may pay. Thecharge does not vary by sex. The charge increases for older Issue Ages.

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Single Premium Life PolicyCharge When Charge is Deducted Current Amount Deducted Maximum Amount Deducted

Charge for Mortalityand Expense Risks

Daily Annual rate of .50% of the Separate Account assets Annual rate of .50% of theSeparate Account Assets

Charge for FederalIncome Taxes

Daily Annual rate of .05% of the Separate Account assets A rate which reflects thatportion of our actual taxexpenses which is fairlyallocable to the Policies

Cost of Insurance Calculated at leastannually on the PolicyAnniversary

Maximum: $1,000 per $1,000 of net amount at risk(Attained Age 99)1

Minimum: $0.69 per $1,000 of net amount at risk(Attained Age 10 female)1

Representative: $21.06 per $1,000 of net amount atrisk (Attained Age 63 male)

Same as current amount,without the current dividend

Charge for Mortalityand Expense Risksand Expenses forLoans2

Daily Annual rate of .85% of the borrowed amount Annual rate of 1.00% of theborrowed amount

1 The Policy includes no provisions for explicit deductions or charges for the cost of insurance, but this cost is reflected in the table of Cash Values at the frontof the Policy and in the table of net single premiums we use to determine the variable insurance amount. The variable insurance amount is used to calculateboth the Death Benefit and the Cash Value. The cost of insurance is based on factors including but not limited to the Insured’s Attained Age, the 1980 CSOMortality Table and the net insurance amount at risk. The net insurance amount at risk is the Death Benefit minus the sum of the Cash Value and any PolicyDebt. The rates shown in the table may not be representative of the charge a particular Owner may pay. The amount you pay for the cost of insurance iseffectively reduced by the dividends, if any, we currently pay on your Policy. You may ask your Financial Representative for the current dividend amount.Future dividends are not guaranteed. (See “Annual Dividends”).

2 The charge is applied to the Policy Debt. The charge shown is a loan interest spread that is deducted from the Invested Assets. We add unpaid interest to theamount of the loan. Interest on a Policy loan accrues and is payable on a daily basis at an annual effective rate of 8% or an alternative variable rate based on abond yield index. The amount of the Policy loan will be transferred from the Divisions to our General Account and credited on a daily basis with an annualearnings rate equal to the Policy loan interest rate less the charge shown.

Annual Portfolio Operating Expenses

The table below shows the range (minimum and maximum) of total operating expenses, including investment advisory fees,distribution (12b-1) fees and other expenses of the Portfolios that you may pay periodically during the time you own the Policy.The first line of this table lists expenses that do not reflect fee waivers or expense limits and reimbursements, nor do they reflectshort-term trading redemption fees, if any, charged by the Portfolios. The information is based on operations for the year endedDecember 31, 2016. More details concerning these fees and expenses are contained in the attached prospectuses for the Funds.

Minimum Maximum

Range of Total Annual Portfolio Operating Expenses (expenses include investment advisory fees, distribution(12b-1) fees, and other expenses as a percentage of average Portfolio assets) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.21% 1.31%

Range of Total Annual Portfolio Operating Expenses After Contractual Fee Waiver or Reimbursement* . . . . . . . 0.21% 1.11%

* The “Range of Total Annual Portfolio Operating Expenses After Contractual Fee Waiver or Reimbursement” line in the above table shows the minimum andmaximum fees and expenses charged by all of the Portfolios after taking into account contractual fee waiver or reimbursement arrangements in place. Thosecontractual arrangements are designed to reduce Total Annual Portfolio Operating Expenses for Owners and will continue for at least one year from the date ofthis prospectus. For more information about which Portfolios currently have such contractual reimbursement or fee waiver arrangements in place, see theprospectuses of the underlying Funds.

For more information about voluntary fee waivers that may be in place, see the “Deductions and Charges” section.

The CompanyThe Northwestern Mutual Life Insurance Company is amutual life insurance company organized by a special act ofthe Wisconsin Legislature in 1857. It is licensed to conduct aconventional life insurance business in the District ofColumbia and in all states of the United States. The totalassets of Northwestern Mutual were over $250 billion as of

December 31, 2016. The Home Office of NorthwesternMutual is located at 720 East Wisconsin Avenue, Milwaukee,Wisconsin 53202.

“Northwestern Mutual,” “Company,” “we,” “us,” and “our” inthis prospectus mean The Northwestern Mutual Life InsuranceCompany.

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General Account assets are used to guarantee the payment ofcertain benefits under the Policies, including death benefits.To the extent that we are required to pay you amounts underthese benefits that are in addition to Invested Assets in theSeparate Account, such amounts will come from GeneralAccount assets. Thus, Owners must look to the strength of theCompany and its General Account with regard to guaranteesunder the Policies. The General Account is exposed to therisks normally associated with the operation of a life insurancecompany, including insurance pricing, asset liability

management and interest rate risk, operational risks, and theinvestment risks of a portfolio of securities that consistslargely, though not exclusively, of fixed-income securities.Some of the risks associated with such a portfolio includeinterest rate, option, liquidity, and credit risk. The financialstatements contained in the Statement of AdditionalInformation include a further discussion of risks inherentwithin the General Account investments. The assets in theGeneral Account are subject to the claims of the Company’sgeneral creditors.

The Separate AccountWe established the Separate Account by action of our Trusteeson November 23, 1983, in accordance with the provisions ofWisconsin insurance law. The Separate Account is registeredwith the SEC as a unit investment trust under the InvestmentCompany Act of 1940 (the “1940 Act”). We own the assets inthe Separate Account and we are obligated to pay all benefitsunder the Policies. We may use the Separate Account tosupport other variable life insurance policies we issue. Wehave divided the Separate Account into Divisions, each ofwhich invests in shares of one Portfolio of the Funds.

Under Wisconsin law, Separate Account assets are heldseparate from our other assets and are not part of our GeneralAccount. Income, gains, and losses, whether or not realized,from assets allocated to the Separate Account will be creditedto or charged against the Separate Account without regard toour other income, gains, or losses. Income, gains, and lossescredited to, or charged against, a Division reflect thatDivision’s own investment performance and not theinvestment performance of our other assets. We may not usethe Separate Account’s assets to pay any of our liabilitiesother than those arising from the Policies and any othervariable life insurance Policies funded by the SeparateAccount. We may, however, use all of our assets (except thoseheld in certain other separate accounts) to satisfy ourobligations under your Policy.

Where permitted by law and subject to any required regulatoryapprovals or votes by Owners, we reserve the right to:

• operate the Separate Account or a Division either as a unitinvestment trust or a management investment company underthe 1940 Act, or in any other form permitted by law, ifdeemed by the Company to be in the best interest of Owners;

• invest current and future assets of a Division in securitiesof another Portfolio as a substitute for shares of a Portfolioalready purchased or to be purchased;

• transfer cash from time to time between the GeneralAccount and the Separate Account as deemed necessary orappropriate and consistent with the terms of the Policy,including but not limited to transfers for the deduction ofcharges and in support of payment options;

• transfer assets of the Separate Account in excess of reserverequirements applicable to the Policies supported by theSeparate Account to the General Account (Invested Assetsremaining in the Separate Account necessary to fulfill itsobligations under the Policy are not subject to claimsagainst or losses in the General Account);

• register or deregister the Separate Account under the 1940Act or change its classification under that Act;

• create new separate accounts;

• add, delete or make substitutions for the securities andother assets held or purchased by the Separate Account;

• restrict or eliminate any voting rights of Owners or otherpersons having voting rights as to the Separate Account; and

• make any changes to the Separate Account to conformwith, or required by any change in, federal tax law, the1940 Act and regulations promulgated thereunder, or anyother applicable federal or state laws.

In the event that we take any of these actions, we may makean appropriate endorsement of your Policy and take otheractions necessary to comply with applicable law.

The FundsA variety of investment options are made available under thePolicy for the allocation of your premiums. However, theCompany does not endorse or recommend any particularoption, nor does it provide investment advice. You areresponsible for choosing your investment options and shouldmake your choices based on your individual situation and risktolerances. After making your initial allocation decisions, you

should monitor your allocations and periodically review theoptions you select and the amounts allocated to each to ensureyour selections continue to be appropriate. The amounts youinvest in a particular Division are not guaranteed and, becauseboth principal and any return on the investment are subject tomarket risk, you can lose money.

Variable Life Prospectus 7

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The assets of each Division are invested in a correspondingPortfolio that is a series of one of the following mutual funds:Northwestern Mutual Series Fund, Inc.; Fidelity® VariableInsurance Products; Neuberger Berman Advisers ManagementTrust; Russell Investment Funds; and Credit Suisse Trust. TheSeparate Account buys shares of the Portfolios at theirrespective net asset values without sales charge. ThePortfolios are available for investment only by separateaccounts supporting variable insurance products and are notpublicly traded. Their performance can differ substantiallyfrom publicly traded mutual funds with similar names. Thespecific Portfolios available under your Policy may changefrom time to time, and not all Portfolios in which assets of theSeparate Account are invested may be available under yourPolicy. Your ability to invest in a Portfolio may be affected bythe actions of such Portfolio, such as when a Portfolio closes.

The investment objectives of each Portfolio are set forthbelow. There is no assurance that any of the Portfolios willachieve its stated objective(s). You can find more detailedinformation about the Portfolios, including a description ofeach Portfolio, in the attached Portfolio prospectuses.Read the prospectuses for the Portfolios carefully beforeinvesting. Please see the prospectuses for the Portfolios for adiscussion of the potential risks and conflicts presented by the

use of a Portfolio as an investment option under variableannuity contracts and variable life insurance policies offeredby affiliated and non-affiliated life insurance companies.Note: If you received a summary prospectus for a Portfoliolisted below, please follow the directions on the first page ofthe summary prospectus to obtain a copy of the full fundprospectus.

Northwestern Mutual Series Fund, Inc. (the“Series Fund”)

The principal investment adviser for the Portfolios of the SeriesFund is Mason Street Advisors, LLC (“MSA”), our wholly-owned company. The investment advisory agreements for therespective Portfolios provide that MSA will provide servicesand bear certain expenses of the Series Fund. MSA employs astaff of investment professionals to manage the assets of theSeries Fund and the other advisory clients of MSA. We providerelated facilities and personnel, which MSA uses in performingits investment advisory functions. MSA has retained andoversees a number of asset management firms under investmentsub-advisory agreements to provide day-to-day management ofthe Portfolios indicated below. Each such sub-adviser may bereplaced without the approval of shareholders. Please see theattached prospectuses for the Series Fund for more information.

Portfolio Investment Objective Sub-adviser (if applicable)

Growth Stock Portfolio Long-term growth of capital; current incomeis a secondary objective

The Boston Company Asset Management,LLC

Focused Appreciation Portfolio Long-term growth of capital Loomis, Sayles & Company, L.P.

Large Cap Core Stock Portfolio Long-term growth of capital and income Fayez Sarofim & Co.

Large Cap Blend Portfolio Long-term growth of capital and income Fiduciary Management, Inc.

Index 500 Stock Portfolio Investment results that approximate theperformance of the Standard & Poor’s 500®

Composite Stock Price Index

N/A

Large Company Value Portfolio Long-term capital growth; income is asecondary objective

American Century Investment Management,Inc.

Domestic Equity Portfolio Long-term growth of capital and income Delaware Investments Fund Advisers, aseries of Macquarie InvestmentManagement Business Trust

Equity Income Portfolio Long-term growth of capital and income T. Rowe Price Associates, Inc.

Mid Cap Growth Stock Portfolio Long-term growth of capital William Blair Investment Management,LLC

Index 400 Stock Portfolio Investment results that approximate theperformance of the S&P MidCap StockPrice 400® Index

N/A

Mid Cap Value Portfolio Long-term capital growth; current income isa secondary objective

American Century Investment Management,Inc.

Small Cap Growth Stock Portfolio Long-term growth of capital Wellington Management Company LLP

Index 600 Stock Portfolio Investment results that approximate theperformance of the Standard & Poor’sSmallCap 600® Index

N/A

Small Cap Value Portfolio Long-term growth of capital T. Rowe Price Associates, Inc.

International Growth Portfolio Long-term growth of capital FIAM LLC

Research International Core Portfolio Capital appreciation Massachusetts Financial Services Company

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Portfolio Investment Objective Sub-adviser (if applicable)

International Equity Portfolio Long-term growth of capital; any incomerealized may be incidental

Templeton Investment Counsel, LLC

Emerging Markets Equity Portfolio Capital appreciation Aberdeen Asset Managers Limited

Government Money Market Portfolio(1) Maximum current income to the extentconsistent with liquidity and stability ofcapital

BlackRock Advisors, LLC

Short-Term Bond Portfolio To provide as high a level of current incomeas is consistent with prudent investment risk

T. Rowe Price Associates, Inc.

Select Bond Portfolio To provide as high a level of total return asis consistent with prudent investment risk; asecondary objective is to seek preservationof shareholders’ capital

Wells Capital Management, Inc.

Long-Term U.S. Government BondPortfolio

Maximum total return, consistent withpreservation of capital and prudentinvestment management

Pacific Investment Management CompanyLLC

Inflation Protection Portfolio Pursue total return using a strategy thatseeks to protect against U.S. inflation

American Century Investment Management,Inc.

High Yield Bond Portfolio(2) High current income and capitalappreciation

Federated Investment ManagementCompany

Multi-Sector Bond Portfolio Maximum total return, consistent withprudent investment management

Pacific Investment Management CompanyLLC

Balanced Portfolio To realize as high a level of total return as isconsistent with prudent investment risk,through income and capital appreciation

N/A

Asset Allocation Portfolio To realize as high a level of total return as isconsistent with reasonable investment risk

N/A

(1) Although the Government Money Market Portfolio seeks to preserve its value at $1.00 per share, it is possible to lose money by investing in the GovernmentMoney Market Portfolio. An investment in a money market portfolio is neither insured nor guaranteed by the Federal Deposit Insurance Corporation or anygovernment agency. During extended periods of low interest rates, the yield of a money market portfolio may also become extremely low and possiblynegative.

(2) High yield bonds are commonly referred to as junk bonds.

Fidelity® Variable Insurance Products

The Fidelity® VIP Mid Cap Portfolio and the Fidelity® VIP Contrafund® Portfolio are series of Variable Insurance Products FundIII and the Variable Insurance Products Fund II, respectively. The Separate Account buys Service Class 2 shares of the Portfolios,the investment adviser for which is the Fidelity Management & Research Company (FMR). The following affiliates of FMR alsoassist with foreign investments: Fidelity Management & Research (U.K.) Inc., Fidelity Management & Research (Hong Kong)Limited, and Fidelity Management & Research (Japan) Inc.

Portfolio Investment Objective Sub-adviser

VIP Mid Cap Portfolio Long-term growth of capital FMR Co., Inc.

VIP Contrafund® Portfolio Long-term capital appreciation FMR Co., Inc.

Neuberger Berman Advisers Management Trust

The Neuberger Berman Advisers Management Trust Socially Responsive Portfolio is a series of the Neuberger Berman AdvisersManagement Trust. The Separate Account buys Class I shares of the Portfolio, the investment adviser for which is NeubergerBerman Investment Advisers LLC.

Portfolio Investment Objective

Socially Responsive Portfolio Long-term growth of capital by investing primarily in securities ofcompanies that meet the Portfolio’s financial criteria and socialpolicy

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Russell Investment Funds

The assets of each of the Portfolios comprising the Russell Investment Funds are invested by one or more investmentmanagement organizations researched and recommended by Russell Investment Management LLC (“RIM”). RIM is theinvestment adviser of the Russell Investment Funds.

Portfolio Investment Objective

U.S. Strategic Equity Fund Long-term growth of capital

U.S. Small Cap Equity Fund Long-term growth of capital

Global Real Estate Securities Fund Current income and long-term growth of capital

International Developed Markets Fund Long-term growth of capital

Strategic Bond Fund Current income and, as a secondary objective, capital appreciation

LifePoints® Variable Target PortfolioSeries Moderate Strategy Fund

Current income and moderate long-term capital appreciation

LifePoints® Variable Target PortfolioSeries Balanced Strategy Fund

Above-average long-term capital appreciation and a moderate levelof current income

LifePoints® Variable Target PortfolioSeries Growth Strategy Fund

High long-term capital appreciation; and as a secondary objective,current income

LifePoints® Variable Target PortfolioSeries Equity Growth Strategy Fund

High long-term capital appreciation

Credit Suisse Trust

The Commodity Return Strategy Portfolio is a series of Credit Suisse Trust. The Separate Account buys shares of the Portfolio,the investment adviser for which is Credit Suisse Asset Management, LLC.

Portfolio Investment Objective

Commodity Return Strategy Portfolio Total Return

Payments We Receive

We select the Portfolios available through this Policy based onseveral criteria, including asset class coverage, the strength ofthe investment adviser’s or sub-adviser’s reputation andtenure, brand recognition, performance, and the capability andqualification of each investment firm. Another factor weconsider during the selection process is whether thePortfolio’s investment adviser or an affiliate will makepayments to us or our affiliates. We review the Portfoliosperiodically and may remove a Portfolio or limit itsavailability to new premiums and/or transfers of accumulatedamounts if we determine that the Portfolio no longer meetsone or more of the selection criteria, and/or if the Portfolio hasnot attracted significant allocations from Owners. The SeriesFund has been included in part because it is managed by asubsidiary of the Company.

We do not provide any investment advice and do notrecommend or endorse any particular Portfolio. You bearthe risk of any decline in the Policy Value of your Policyresulting from the performance of the Portfolios you havechosen.

Owners, through their indirect investment in the Portfolios,bear the costs of the investment advisory or management feesthat the Portfolios pay to their respective investment advisors(see the Portfolios’ prospectuses for more information). Asdescribed above, an investment adviser of a Portfolio, or itsaffiliates, may make payments to the Company and/or certain

of our affiliates, which is generally a positive factor whenselecting Portfolios. However, the amount of such payments isnot determinative as to whether a Portfolio is availablethrough the Policy. These payments may be derived, in wholeor in part, from the advisory fee deducted from Portfolioassets. The amount of the compensation is based on apercentage of assets of the Portfolios attributable to thePolicies and certain other variable insurance products that theCompany issues. The percentages differ and some investmentadvisers (or other affiliates) may pay more than others. Thepercentages currently range up to 0.25%. These payments maybe used for various purposes, including payment of expensesthat the Company and/or its affiliates incur for servicesperformed on behalf of the Policies and the Portfolios. TheCompany and its affiliates may profit from these payments.

Certain Portfolios have also adopted a Distribution (and/orShareholder Servicing) Plan under Rule 12b-1 of the 1940Act, which is described in more detail in the Portfolios’prospectuses. These payments, which may be up to 0.25%, arededucted from assets of the Portfolios and are paid to ourdistributor, Northwestern Mutual Investment Services, LLC.These payments decrease a Portfolio’s investment return. Wealso consider the receipt of these payments generally to be apositive factor when selecting Portfolios.

Additionally, an investment adviser or sub-adviser of aPortfolio (or of an underlying fund in which a Portfolio

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invests) or its affiliate may provide the Company withwholesaling services that assist in the distribution of thePolicies and may pay the Company and/or certain of ouraffiliates amounts to participate in sales meetings. These

amounts may be significant and may provide the investmentadviser or sub-adviser (or their affiliate) with increased accessto persons involved in the distribution of the Policies.

Information About the PoliciesWe are no longer issuing these Policies.

This prospectus describes the material provisions of thePolicies. You should consult your Policy for more informationabout its terms and conditions, and for any state specificvariations that may apply to your Policy.

Premiums

For Whole Life Policies and, except as explained below, forExtra Ordinary Life Policies, premiums are level, fixed andpayable in advance during the Insured’s lifetime on a monthly,quarterly, semiannual or annual basis. You may change thepremium frequency. The change will be effective when weaccept the premium on the new frequency. The amount of thepremium depends on the amount of insurance for which thePolicy was issued and the Insured’s age and underwritingclassification. The amount of the premium also reflects the sexof the Insured except where state or federal law requires thatpremiums and other charges and values be determined withoutregard to sex. We send a notice to the Owner not less than twoweeks before each premium is due. If you select the monthlypremium frequency, we may require that you make PremiumPayments through an automatic payment plan arranged withyour bank.

Premiums you pay other than on an annual basis are increasedto (1) reflect the time value of money, based on a 12% interestrate, and (2) cover the administrative costs to process theadditional Premium Payments. You may obtain informationfrom your Northwestern Mutual Financial Representativeabout annual percentage rate (APR) calculations for premiumspaid other than annually. The APR calculation is alsoavailable through www.northwesternmutual.com.

Premium added to the Separate Account will increase yourPolicy Value according to a formula specified in your Policythat takes into account certain actuarially determined valuesand the 1980 CSO mortality tables.

If the Insured dies after payment of the premium for the periodwhich includes the date of death, we will refund the portion of

the premium for the remainder of that period as part of thePolicy proceeds.

You may send Premium Payments to our Home Office or to apayment center designated by us. All payments must be madein U.S. Dollars payable through a U.S. financial institution.We accept Premium Payments by check or electronic fundstransfer (“EFT”). We generally will not accept cash, moneyorders, traveler’s checks or “starter” checks; however, inlimited circumstances, we may accept some cash equivalentsin accord with our anti-money laundering procedures. If youmake a Premium Payment with a check or bank draft and, forwhatever reason, it is later returned unpaid or uncollected, orif a Premium Payment by EFT is reversed, we reserve theright to reverse the transaction. If mandated under applicablelaw, we may be required to reject a Premium Payment. Wemay also be required to provide information about you andyour account to government regulators.

We accept Premium Payments via our website if eligible.Electronic payments via our website must be made inaccordance with our current procedures. However, we are notrequired to accept electronic payments, and we will not beresponsible for losses resulting from transactions based onunauthorized electronic payments, provided we followprocedures reasonably designed to verify the authenticity ofelectronic payments. For more information on electronicpayments see “Owner Inquiries.” We reserve the right to limit,modify, suspend or terminate the ability to make payments viaour website at any time.

Whole Life Policy The following table for Whole LifePolicies shows representative premiums for male select,standard plus, and standard risks for various face amounts ofinsurance. Premiums you pay other than on an annual basisare increased to (1) reflect the time value of money, based ona 12% interest rate and (2) cover the administrative costsassociated with additional Premium Payments. For example,two semi-annual payments will total more than an annualpremium payment.

Age atIssue

FaceAmount

AnnualPremium

MonthlyPremium

Annual Sumof MonthlyPremiums*

Annual Sum of MonthlyPremiums Minus theAnnual Premium

SELECT15 . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50,000 $ 382.50 $ 33.60 $ 403.20 $ 20.7035 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 1,536.00 135.10 1,621.20 85.2055 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 3,766.00 331.10 3,973.20 207.20

STANDARD PLUS15 . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50,000 $ 406.00 $ 35.60 $ 427.20 $ 21.2035 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 1,683.00 148.10 1,777.20 94.2055 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 4,125.00 363.10 4,357.20 232.20

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Age atIssue

FaceAmount

AnnualPremium

MonthlyPremium

Annual Sumof MonthlyPremiums*

Annual Sum of MonthlyPremiums Minus theAnnual Premium

STANDARD15 . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50,000 $ 491.50 $ 43.10 $ 517.20 $ 25.7035 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 1,912.00 168.10 2,017.20 105.2055 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 4,587.00 404.10 4,849.20 262.20

* In some cases for policies with smaller premiums, the sum of 12 monthly premiums may be less than the sum of other periodic premium amounts due to loweradministrative costs.

Extra Ordinary Life Policy The following table for Extra Ordinary Life Policies shows representative annual premiums formale select, standard plus and standard risks for various amounts of insurance. Premiums you pay other than on an annual basisare increased to (1) reflect the time value of money, based on a 12% interest rate and (2) cover the administrative costs associatedwith additional Premium Payments. For example, two semi-annual payments will total more than an annual premium payment.The amounts of insurance shown in the table are the total amounts in effect when the Extra Ordinary Life Policy is issued,including both the guaranteed minimum death benefit noted in your Policy (“Minimum Death Benefit”), which we guarantee forthe lifetime of the Insured, and the Extra Life Protection, which we guarantee for a shorter period. (See “Death Benefit” and“Extra Ordinary Life Policy”).

Age atIssue

FaceAmount

AnnualPremium

MonthlyPremium

Annual Sumof MonthlyPremiums*

Annual Sum of MonthlyPremiums Minus theAnnual Premium

SELECT15 . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50,000 $ 261.50 $ 23.10 $ 277.20 $ 15.7035 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 1,014.00 89.10 1,069.20 55.2055 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 2,612.00 230.10 2,761.20 149.20

STANDARD PLUS15 . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50,000 $ 285.00 $ 25.10 $ 301.20 $ 16.2035 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 1,161.00 102.10 1,225.20 64.2055 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 2,971.00 261.10 3,133.20 162.20

STANDARD15 . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50,000 $ 357.50 $ 31.60 $ 379.20 $ 21.7035 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 1,377.00 121.10 1,453.20 76.2055 . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000 3,425.00 301.10 3,613.20 188.20

* In some cases for policies with smaller premiums, the sum of 12 monthly premiums may be less than the sum of other periodic premium amounts due to loweradministrative costs.

Single Premium Life Policy The Single Premium LifePolicy was available only for applicants who met select orstandard plus underwriting criteria as we determined. Thepremiums for these Policies are the same for both select andstandard plus risks, but we expect that the dividends will belower for Policies issued to Insureds in the standard plusclassification.

The following table for Single Premium Life Policies showsrepresentative gross single premiums for male select andstandard plus risks for various face amounts of insurance:

Age atIssue

Face Amountof Insurance

Gross SinglePremium

15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $10,000 $ 1,498.4035 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25,000 6,443.2555 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50,000 23,502.00

Grace Period

For the Whole Life and Extra Ordinary Life Policies there is agrace period of 31 days for any premium that is not paid whendue. The Policy remains in force during this period. If you donot pay the premium within the grace period, the Policy willterminate as of the date when the premium was due and willno longer be in force, unless it is continued as extended termor paid-up insurance (see “Extended Term and Paid-Up

Insurance”), or the Automatic Premium Loan provision iscurrently in effect (see “Policy Loans and Automatic PremiumLoans”) to pay any overdue premiums and the premium due isless than the maximum amount allowable. If the Insured diesduring the grace period we will deduct any overdue premiumfrom the proceeds of the Policy. If the Insured dies afterpayment of the premium for the period which includes thedate of death, we will refund the portion of the premium forthe remainder of that period as part of the Policy proceeds.

Allocating Premiums to the Separate Account

We place the net annual premium for a Whole Life Policy oran Extra Ordinary Life Policy in the Separate Account on thePolicy Date and on the Policy Anniversary each year. The netannual premium is the annual premium less the deductions.See “Deductions and Charges” for more information.

You determine how the net annual premium for a Whole Lifeor an Extra Ordinary Life Policy is apportioned among theDivisions. If you direct any portion of a premium to aDivision, the Division must receive at least 10% of thatpremium. You may change the apportionment for futurepremiums by written request at any time, but the change willbe effective only when we place the net annual premium in the

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Separate Account on the next Policy Anniversary, even if youare paying premiums other than on an annual basis. Undercertain circumstances in accordance with our procedures yourFinancial Representative may provide us with instructions onyour behalf involving the allocation of amounts amongavailable Divisions, subject to our rules and requirements,including the restrictions on short-term and excessive trading.

Eligible Owners may also submit allocation requests via theVariable Life Service Center at 1-866-424-2609 or via ourwebsite at www.northwesternmutual.com (“ElectronicInstructions”) in accordance with our then-current proceduresfor Electronic Instructions provided you have properlyauthorized us to accept Electronic Instructions in advance ofyour request. For more information see “Owner Inquiries.”However, we are not required to accept ElectronicInstructions, and we will not be responsible for lossesresulting from transactions based on unauthorized ElectronicInstructions, provided we follow procedures reasonablydesigned to verify the authenticity of Electronic Instructions.

For a Single Premium Policy we placed the entire singlepremium, less an administrative charge of $150, in theSeparate Account on the Policy Date, and we apportioned theamount among the Divisions as you determined.

You may apportion the Separate Account assets supportingyour Policy among as many as six Divisions at any time.

Transfers Between Divisions Subject to the short-term andexcessive trading limitations described below, you maytransfer accumulated amounts from one Division to another solong as you are invested in no more than six Divisions at atime. Transfer requests will be effective after our receipt ofyour request in Good Order at our Home Office. If we receiveyour request for transfer before the close of trading (typically,4:00 p.m. Eastern Time) on the NYSE, we will deem yourrequest to be received and effective that day. If we receiveyour request for transfer on or after the close of trading on theNYSE, we will deem your request to be received and effectiveon the next regular trading session of the NYSE. If yourrequest is not in Good Order, either we or your FinancialRepresentative may notify you in writing, by telephone or byemail in an effort to conform your request to our then-currentrequirements.

In order to take full advantage of these features, you shouldcarefully consider, on a continuing basis, which investmentoptions are best suited to your long-term investment needs.Although no fee is presently charged, we reserve the rightwhere allowed by state law to charge a fee that will cover theadministrative costs of transfers. In addition, certain Portfoliosin which the Divisions invest may impose redemption fees.These fees are described in the Portfolios’ prospectuses.Transfer requests must be in amounts greater than or equal to1% of Invested Assets or the request will not be processed.When a transfer is made from any Division, the resultingallocation of Invested Assets must be in whole percentages inall Divisions that have any Invested Assets as a result of thetransfer. Under certain circumstances in accordance with ourprocedures your Financial Representative may provide us with

instructions on your behalf involving the transfer ofaccumulated amounts among available Divisions, subject toour rules and requirements, including the restrictions on short-term and excessive trading discussed below.

You may request the transfer in writing at our Home Office,via the Variable Life Service Center at 1-866-424-2609 or, ifeligible, via our website at www.northwesternmutual.com.The submission of transfer instructions by telephone orthrough our website (“Electronic Instructions”) must be madein accordance with our current procedures for ElectronicInstructions and you must properly authorize us to acceptElectronic Instructions in advance of your request. For moreinformation see “Owner Inquiries.” However, we are notrequired to accept Electronic Instructions, and we will not beresponsible for losses resulting from transactions based onunauthorized Electronic Instructions, provided we followprocedures reasonably designed to verify the authenticity ofElectronic Instructions. We reserve the right to limit, modify,suspend or terminate the ability to make transfers viaElectronic Instructions.

Short-Term and Excessive Trading Short-term andexcessive trading (sometimes referred to as “market timing”)may present risks to a Portfolio’s long-term investors, such asOwners and other persons who may have material rights underthe Policy (e.g., beneficiaries), because it can, among otherthings, disrupt Portfolio investment strategies, increasePortfolio transaction and administrative costs, require higherthan normal levels of cash reserves to fund unusually large orunexpected redemptions, and adversely affect investmentperformance. These risks may be greater for Portfolios thatinvest in securities that may be more vulnerable to arbitragetrading, including foreign securities and thinly tradedsecurities, such as small cap stocks and non-investment gradebonds. These types of trading activities also may dilute thevalue of long-term investors’ interests in a Portfolio if itcalculates its net asset value using closing prices that are nolonger accurate. Accordingly, we discourage market timingactivities.

To deter short-term and excessive trading, we have adoptedand implemented policies and procedures which are designedto control abusive trading practices. We seek to apply thesepolicies and procedures uniformly to all Owners. Anyexceptions must be either expressly permitted by our policiesand procedures or subject to an approval process described inthem. We may also be prevented from uniformly applyingthese policies and procedures under applicable state or federallaw or regulation. Because exceptions are permitted, it ispossible that investors may be treated differently and, as aresult, some may be allowed to engage in trading activity thatmight be viewed as market timing.

Among the steps we have taken to reduce the frequency andeffect of these practices are monitoring trading activity andimposing trading restrictions, including the prohibition ofmore than twelve transfers among Divisions under a singlePolicy during a Policy Year. Multiple transfers with the sameeffective date made by the same Owner will be counted as a

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single transfer for purposes of applying the twelve transferlimitation. Further, an investor who is identified as havingmade a transfer in and out of the same Division, excluding theGovernment Money Market Division, (“round trip transfer”)in an amount in excess of $10,000 within fourteen calendardays will be restricted from making additional transfers aftermaking two more such round trip transfers within any PolicyYear, including the year in which the first such round triptransfer was made. The restriction will last until the nextPolicy Anniversary and the Policy Owner will be sent a letterinforming him or her of the restriction. An Owner who isidentified as having made one round trip transfer within thirtycalendar days aggregating more than one percent (1%) of thetotal assets of the Portfolio underlying a Division, excludingthe Government Money Market Division and the Divisionscorresponding to the Portfolios of the Russell InvestmentFunds LifePoints® Variable Target Portfolio Series, will berestricted from making additional transfers after making onemore such round trip transfer within any Policy Year,including the year in which the first such round trip transferwas made. The restriction will last until the next PolicyAnniversary and the Policy Owner will be sent a letterinforming him or her of the restriction. Unless we believe yourtrading behavior to be inconsistent with these short-term andexcessive trading policies, these limitations will not apply toautomatic asset transfers, scheduled or systematic transactionsinvolving portfolio rebalancing, dollar cost averaging, initialallocations or changes in future allocations, to the extent thesefeatures are available under your Policy. Once a Policy isrestricted, we will allow one additional transfer into theGovernment Money Market Division until the next PolicyAnniversary. Additionally, in accordance with our procedures,we may modify some of these limitations to allow fortransfers that would not count against the total transfer limitbut only as necessary to alleviate any potential hardships toOwners (e.g., in situations involving a substitution of anunderlying fund).

Policies such as yours (or other Policies supported by theSeparate Account) may be purchased by a corporation or otherentity as a means to informally fund the liabilities created bythe entity’s employee benefit or similar plan. These Policiesmay be aggregately managed to match liabilities under suchplans. Policies sold under these circumstances may be subjectto special transfer restrictions. Namely, transactions involvingportfolio rebalancing programs may be exempt from thetwelve transfers per Policy year limitation where: (1) thepurpose of the portfolio rebalancing program is to match thePolicy to the entity’s employee benefit or similar plan; (2) theportfolio rebalancing program adequately protects againstshort-term or excessive trading; and (3) the portfoliorebalancing program is managed by a third party administratorthat meets our requirements. We reserve the right to monitoror limit transactions involving portfolio rebalancing programswhere we believe such transactions may be potentiallyharmful to a Portfolio.

We may change these policies and procedures from time totime in our sole discretion without notice; provided, however,Owners will be given advance, written notice if the policies

and procedures are revised to accommodate market timing.Additionally, the Funds may have their own policies andprocedures described in their prospectuses that are designed tolimit or restrict frequent trading. Such policies may bedifferent from our policies and procedures, and may be moreor less restrictive. As the Funds may accept purchasepayments from other investors, including other insurancecompany separate accounts on behalf of their variable productcustomers and retirement plans, we cannot guarantee that theFunds will not be harmed by any abusive market timingactivity relating to the retirement plans and/or other insurancecompanies that may invest in the Funds. The Funds’ policiesand procedures may provide for the imposition of aredemption fee and, upon request from the Fund, require us toprovide transaction information to the Fund (including anOwner’s tax identification number) and to restrict or prohibittransfers and other transactions that involve the purchase ofshares of a Portfolio. In the event a Fund instructs us to restrictor prohibit transfers or other transactions involving shares of aPortfolio, you may not be able to make additional purchases ina Division until the restriction or prohibition ends. If yousubmit a request that includes a purchase or transfer into sucha restricted Division, we will consider the request “not inGood Order” and it will not be processed. You may, however,submit a new transfer request.

If we believe your trading activity is in violation of, orinconsistent with, our policies and procedures or otherwise ispotentially disruptive to the interests of other investors, youmay be asked to stop such activities, and future investmentsand allocations or transfers by you may be rejected withoutprior notice. Because we retain discretion to determine whataction is appropriate in a given situation, investors may betreated differently and some may be allowed to engage inactivities that might be viewed as market timing.

We intend to monitor events and the effectiveness of ourpolicies and procedures in order to identify whether instancesof potentially abusive trading practices are occurring.However, we may not be able to identify all instances ofabusive trading practices, nor completely eliminate thepossibility of such activities, and there may be technologicallimitations on our ability to impose restrictions on the tradingpractices of Owners.

Deductions and Charges

The Net Premiums we place in the Separate Account forWhole Life, Extra Ordinary Life and Single Premium LifePolicies are the gross premiums after the deductions describedin the next two sections below. The Net Premiums for WholeLife and Extra Ordinary Life Policies exclude any extrapremium we charge for Insureds who do not qualify as selectrisks and the extra premium for any optional benefits. Wemake a charge for mortality and expense risks against theassets of the Separate Account. There is also a charge fortaxes. (See “Charges Against the Separate Account Assets”).In addition, the funds in which the Separate Account assets areinvested pay an investment advisory fee and certain otherexpenses. (See “Fee and Expense Tables—Annual Portfolio

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Operating Expenses” and the attached Fund prospectuses.)

We may impose a fee for transfers that will not exceed ouradministrative costs associated with transfers. This fee iscurrently being waived.

You may have the option of receiving funds via wire transferor priority mail. Currently, a fee of $25 is charged for wiretransfers (up to $50 for international wires) and a $15 fee (upto $45 for next day, a.m. delivery) for priority mail. These feesare to cover our administrative costs or other expenses. Wemay discontinue the availability of these options at any time,with or without notice.

Deductions from Premiums for Whole Life and ExtraOrdinary Life Policies The deductions described in thissection are for Whole Life and Extra Ordinary Life Policiesonly. The deductions for Single Premium Life Policies aredescribed under the next caption below.

For the first Policy Year there was a one-time deduction of notmore than $5 for each $1,000 of insurance, based on the faceamount for Whole Life or the Minimum Death Benefit statedin the Policy for Extra Ordinary Life. This was for the costs ofprocessing applications, medical examinations, determininginsurability and establishing records.

There is an annual deduction of $35 for administrative costs tomaintain the Policy. Expenses include costs of premiumbilling and collection, processing claims, keeping records andcommunicating with Owners.

There is a deduction each year for sales costs. This amountmay be considered a sales load. The deduction will be notmore than 30% of the basic premium (as defined below) forthe first Policy Year, not more than 10% for each of the nextthree years and not more than 7% each year thereafter. Thebasic premium for a Policy is the gross premium which wouldbe payable if you paid the premium annually, less the annualdeduction of $35 for administrative costs. The basic premiumis based on the cost of insurance for Insureds who qualify asselect risks and does not include any extra premium amountsfor Insureds whom we place in other underwritingclassifications. The basic premium does not include the extrapremium for any optional benefits. For an Extra Ordinary LifePolicy, the basic premium does not include any extra premiumfor the Extra Life Protection.

The amount of the deduction for sales costs for any PolicyYear is not specifically related to sales costs we incur for thatyear. We expect to recover our total sales expenses from theamounts we deduct for sales costs over the period while thePolicies are in force. To the extent that sales expenses exceedthe amounts deducted, we will pay the expenses from ourother assets. These assets may include, among other things,any gain realized from the charge against the assets of theSeparate Account for the mortality and expense risks weassume. (See “Charges Against the Separate AccountAssets”). To the extent that the amounts deducted for salescosts exceed the amounts needed, we will realize a gain.

We make a deduction equal to 2% of each basic premium forstate premium taxes. Premium taxes vary from state to stateand currently range from 0% to 3.5% of life insurance

premiums. The 2% rate is an average, and we charge the samepercentage regardless of the state in which you live, whichmay be more or less than the percentage charged by your stateof residence.

Provided that all premiums are paid when due, we guaranteethat the Death Benefit, before adjustments, for a Whole LifePolicy will never be less than the face amount of the Policy,regardless of the investment experience of the SeparateAccount and that, for an Extra Ordinary Life Policy, the DeathBenefit, before adjustments, will never be less than theMinimum Death Benefit stated in the Policy. For bothPolicies, there is a deduction equal to 1.5% of each basicpremium to compensate us for the risk that the Insured maydie at a point in time when the Death Benefit that wouldordinarily be paid is less than this guaranteed minimumamount.

For an Extra Ordinary Life Policy there is a deduction fordividends. This deduction will vary by age of the Insured andduration of the Policy and we expect it to be in the range ofapproximately 7-17% of the gross annual premium. Thededuction is in consideration of the Policy’s receipt ofdividends that may be paid or credited in accordance with thedividend scale in effect on the issue date of the Policy.Dividends will be affected by, among other factors, whetherthe Policy includes a term insurance component. Futuredividends are not guaranteed. (See “Annual Dividends”).

The following tables illustrate the amount of net annualpremium, for select and standard risks, to be placed in theSeparate Account at the beginning of each Policy Year afterthe deductions described above:

Whole Life

Beginning ofPolicy Year

Male Age 35 - Select RiskAnnual Premium

$500 $1,000 $5,000

1 . . . . . . . . . . . . . . . . . . . . . $ 154.28 $ 320.16 $ 1,647.282 through 4 . . . . . . . . . . . . . 402.11 834.48 4,293.515 and later . . . . . . . . . . . . . 416.05 863.41 4,442.36

Beginning ofPolicy Year

Male Age 35 - Standard RiskAnnual Premium

$500 $1,000 $5,000

1 . . . . . . . . . . . . . . . . . . . . . $ 123.37 $ 256.03 $ 1,317.302 through 4 . . . . . . . . . . . . . 321.57 667.33 3,433.445 and later . . . . . . . . . . . . . 332.71 690.46 3,552.48

Extra Ordinary Life

Beginning ofPolicy Year

Male Age 35 - Select RiskAnnual Premium

$500 $1,000 $5,000

1 . . . . . . . . . . . . . . . . . . . . . $ 134.23 $ 278.56 $ 1,433.212 through 4 . . . . . . . . . . . . . 369.62 767.07 3,946.645 and later . . . . . . . . . . . . . 383.58 796.05 4,095.74

Beginning ofPolicy Year

Male Age 35 - Standard RiskAnnual Premium

$500 $1,000 $5,000

1 . . . . . . . . . . . . . . . . . . . . . $ 97.92 $ 203.21 $ 1,045.542 through 4 . . . . . . . . . . . . . 269.65 559.59 2,879.115 and later . . . . . . . . . . . . . 279.83 580.73 2,987.88

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Deductions for Single Premium Life Policies For a SinglePremium Life Policy, the only deduction from the singlepremium was an administrative charge of $150. Theadministrative costs for issuing and maintaining a SinglePremium Life Policy are similar to those we incur with aWhole Life Policy or an Extra Ordinary Life Policy, exceptfor the costs of premium billing and collection. (See“Deductions from Premiums for Whole Life and ExtraOrdinary Life Policies”). We placed the entire premium for aSingle Premium Life Policy, after this deduction of $150, inthe Separate Account when we issued the Policy without anyof the other deductions which apply to premiums for WholeLife and Extra Ordinary Life Policies. There is no annual feefor a Single Premium Life Policy.

For a Single Premium Life Policy during the first ten PolicyYears, the Cash Value payable on surrender of the Policy wasreduced by a deduction for sales costs. The deduction duringthe first Policy Year was not more than 9% of the Policy’stabular Cash Value. (See “Cash Value”). The deductiondecreased over time until it was eliminated at the end of thetenth Policy Year. We intended the deduction to recover thecosts we incurred in distributing Single Premium Life Policieswhich were surrendered in their early years. The deductionwas never more than 9% of the single premium paid for thePolicy, excluding the administrative charge of $150.

The following table illustrates the schedule for the decreasingdeduction for sales costs for a policy surrendered at the end ofeach of the first ten Policy Years. The illustration is for aSingle Premium Life Policy, male age 35. The schedule variesslightly by age and sex and amount of insurance.

Policy Year End WhenPolicy Is Surrendered

Deduction as % ofTabular Cash Value

1 . . . . . . . . . . . . . . . . . . . . . . . . . 7.9%2 . . . . . . . . . . . . . . . . . . . . . . . . . 7.13 . . . . . . . . . . . . . . . . . . . . . . . . . 6.34 . . . . . . . . . . . . . . . . . . . . . . . . . 5.45 . . . . . . . . . . . . . . . . . . . . . . . . . 4.66 . . . . . . . . . . . . . . . . . . . . . . . . . 3.77 . . . . . . . . . . . . . . . . . . . . . . . . . 2.88 . . . . . . . . . . . . . . . . . . . . . . . . . 1.99 . . . . . . . . . . . . . . . . . . . . . . . . . 0.910 and subsequent years . . . . . . 0

Charges Against the Separate Account Assets There is adaily charge to the Separate Account for the mortality andexpense risks that we have assumed. The charge is at theannual rate of .50% of the assets of the Separate Account. Themortality risk is that Insureds may not live as long as weestimated. The expense risk is that expenses of issuing andadministering the Policies may exceed the estimated costs,including other costs such as those related to marketing anddistribution. The actual mortality and expense experienceunder the Policies will be a factor used in determiningdividends. (See “Annual Dividends”).

The Policies provide that we may make a charge for taxesagainst the assets of the Separate Account. Currently, we aremaking a daily charge for income taxes we incur at the annualrate of .05% of the assets of the Separate Account. We may

increase, decrease or eliminate the charge for taxes in thefuture to reflect the portion of our actual tax expenses which isfairly allocable to the Policies.

Optional Benefits There is a separate charge for anyoptional benefit you have selected. (See “Other PolicyProvisions—Optional Benefits”). For a Whole Life Policy, theWaiver of Premium Benefit has a maximum charge of $2.05per $1,000 of face amount and a minimum charge of $0.13 per$1,000 of face amount. The Additional Purchase Benefit has amaximum charge of $2.21 per $1,000 of Additional PurchaseBenefit and a minimum charge of $0.54 per $1,000 ofAdditional Purchase Benefit.

For an Extra Ordinary Life Policy, the Waiver of PremiumBenefit has a maximum charge of $1.48 per $1,000 of faceamount and a minimum charge of $0.10 per $1,000 of faceamount. The Additional Purchase Benefit has a maximumcharge of $2.21 per $1,000 of Additional Purchase Benefit anda minimum charge of $1.06 per $1,000 of Additional PurchaseBenefit.

We will realize a gain from these charges to the extent theyare not needed to provide benefits and pay expenses under thePolicies, in which case the gain may be used for any Companypurpose.

The investment performances of each Division reflects allexpenses borne by the corresponding Portfolios. For certainPortfolios, certain expenses may have been reimbursed or feesmay have been waived during 2016. It is anticipated that anyvoluntary expense reimbursement and fee waiverarrangements would continue past the current year, althoughcertain arrangements may be terminated at any time. Aftertaking into account these arrangements and any contractualfee waiver or expense reimbursement arrangements, AnnualPortfolio Operating Expenses would have ranged from aminimum of 0.21% to a maximum of 1.11%. (See “Fee andExpense Tables—Annual Portfolio Operating Expenses” andthe attached Fund prospectuses.)

Guarantee of Premiums, Deductions and Charges

We guarantee that the premiums, the amounts we deduct frompremiums, and the charge for mortality and expense risks willnot increase over time. These amounts will not increaseregardless of future changes in longevity or increases inexpenses. The Extra Ordinary Life Policy provides anopportunity to pay an additional amount of premium after theguaranteed period for the Extra Life Protection has expired ifthe total Death Benefit would otherwise fall below the initialamount of insurance. (See “Extra Ordinary Life Policy”).

Death Benefit

If an Income Plan was not previously elected by the Ownerand in lieu of a lump sum payment, Death Benefits, less anyPolicy Debt, may be paid under an Income Plan selected byyour beneficiary after the death of the Insured. AvailableIncome Plans include an interest income plan, installmentincome plans, and life income plans. The Company may offeradditional Income Plans. Generally, (1) an interest Income

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Plan accrues interest on the Death Benefit, the interest may bereceived monthly, and any remaining proceeds or interest maybe withdrawn at any time; (2) an installment Income Plan paysDeath Benefit proceeds in installments for a fixed period oftime, and any remaining proceeds may be withdrawn at anytime; and (3) a life Income Plan makes payments monthly fora chosen period and after that, for the life of the person onwhose life the payments are based (or two persons if the jointoption is selected). Any proceeds added to increase theamount payable under a monthly income plan may be subjectto a 2.00% expense charge plus any applicable state premiumtax. The choice of income plans will vary depending onfinancial situation and the amount of income desired monthlyfor a chosen time period. The Owner may elect an IncomePlan while the Insured is living or, if the Insured is not theOwner, during the first 60 days after the Insured’s date ofdeath. An Income Plan that is elected by the Owner will takeeffect on the date of death of the Insured if the notice ofelection is received in our Home Office while the Insured isliving. In all other cases, the Income Plan will take effect onthe date of receipt of the notice of election. If no Income Planis elected, the benefit is paid to the beneficiary with interestbased on rates declared by the Company or as required byapplicable state law on the date of death of the Insured.Payments under these plans are from our General Account,and are subject to the claims of our creditors. Owners mustlook to the financial strength of the Company and its GeneralAccount with regard to guarantees under the Policy.

The amount payable under the Death Benefit will be reducedby the amount of any Policy Debt. Subject to the terms andconditions of the Policy, the proceeds will be paid to abeneficiary or other payee after proof of the death of theInsured is received in our Home Office. The amount ofproceeds will be determined as of the date of death. We willpay interest on the proceeds from that date until payment ismade.

The Death Benefit for a variable life insurance policy is, inpart, a guaranteed amount which will not be reduced duringthe lifetime of the Insured so long as you pay premiums whenthey are due and no Policy Debt is outstanding. The remainderof the Death Benefit is the variable insurance amount whichfluctuates in response to actual investment results and is notguaranteed. The amount of any paid-up additions is alsoincluded in the total Death Benefit and, in addition, the ExtraOrdinary Life Policy provides some term insurance during theearly Policy Years. Paid-up additions are amounts ofpermanent insurance, paid for with dividends and added to abasic life insurance policy, and for which the premium for theentire lifetime of the Insured has been paid. Paid-up additionshave Cash Value and loan value. The relationships among theguaranteed and variable amounts and any paid-up additionsand term insurance depend on the design of the particularPolicy. For a more detailed description of how the DeathBenefit is calculated for your Policy, see “Whole Life Policyand Single Premium Life Policy” and “Extra Ordinary LifePolicy” below.

Variable Insurance Amount The variable insuranceamount reflects, on a cumulative basis, the investment

experience of the Divisions in which the Policy hasparticipated. We adjust the variable insurance amountannually on each Policy Anniversary. For the first Policy Yearthe variable insurance amount was zero. For any subsequentyear it may be either positive or negative. If the variableinsurance amount is positive, subsequent good investmentresults will produce a larger variable insurance amount andtherefore an increase in the Death Benefit. If the variableinsurance amount is negative, subsequent good investmentresults will first have to offset the negative amount before theDeath Benefit will increase.

In setting the premium rates for each Policy we have assumedthat investment results will cause the Separate Account assetssupporting the Policy to grow at a net annual rate of 4%. If theassets grow at a net rate of exactly 4% for a Policy Year, thevariable insurance amount will neither increase nor decreaseon the following Policy anniversary. If the net rate of growthexceeds 4%, the variable insurance amount will increase. If itis less than 4%, the variable insurance amount will decrease.

The method for calculating the changes in the Death Benefit isdescribed in the Policy. The Policy includes a table of netsingle premiums used to convert the investment results for aPolicy into increases or decreases in the variable insuranceamount. The insurance rates in the table depend on the sex andthe Attained Age of the Insured for each Policy Year. For aWhole Life Policy, the changes in the Death Benefit will besmaller for a Policy issued with a higher premium for extramortality risk. The net single premium for a particular variableinsurance amount is the price for that amount of paid-upwhole life insurance based on the Insured’s age on the PolicyAnniversary.

To illustrate how the variable insurance amount affects theDeath Benefit for a Whole Life Policy, suppose that on yourPolicy Anniversary investment results since your last PolicyAnniversary (excluding investment results on paid-upadditions) were $500 less than the amount that would havebeen expected assuming a net annual growth rate of 4%. Byway of example, if your net single premium (based on yourunderwriting classification as indicated in your Policy) per$1.00 of insurance was .40440, the variable insurance amountfor the current year will decrease by $1,236 ($500/.40440),thereby decreasing the Death Benefit if the variable insuranceamount had been positive. (See “Whole Life Policy and SinglePremium Life Policy”).

Because the variable insurance amount is adjusted only on thePolicy Anniversary, we bear the risk that the Insured may diebefore the next anniversary after an interim period of adverseinvestment experience. If investment experience during theinterim period is favorable, you will forgo the benefit and wewill realize a gain. However, if on the date of death of theInsured the value of the Policy, considered as a net singlepremium, would buy more Death Benefit than the amountotherwise determined under the Policy, we will pay thisincreased Death Benefit.

The cost of life insurance increases with the advancing age ofthe Insured, and therefore a larger dollar amount of investmentearnings is required to produce the same increase in the Death

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Benefit in the later Policy Years. In general, however, theeffect of investment results on the Death Benefit will tend tobe greater in the later Policy Years because the amount ofassets invested for the Policy will tend to increase as thePolicy remains in force.

The cost of providing insurance protection under a Policy isreflected in the Cash Value of the Policy. (See “Cash Value”).The cost is actuarially computed for each Policy each year,based on the Insured’s Attained Age, the 1980 CommissionersStandard Ordinary Mortality Table and the net insuranceamount at risk under the Policy. The net insurance amount atrisk is the Death Benefit for the Policy minus the sum of theCash Value and any Policy Debt. The cost of insurance differseach year because the probability of death increases as theInsured advances in age, and the net insurance amount at riskdecreases or increases from year to year depending oninvestment experience. The cost assumes that all Insureds arein the select underwriting classification. The differences in themortality rates of the various underwriting classifications arereflected in the different premiums (or different dividendscales) for those underwriting classifications. The cost ofinsurance is based on the mortality table identified above andwe guarantee it for the life of a Policy regardless of any futurechanges in mortality experience. Our revenues attributable tothis charge may exceed our costs attributable to this charge, inwhich case we may realize a gain.

Whole Life Policy and Single Premium Life Policy For aWhole Life Policy or a Single Premium Life Policy the DeathBenefit is the face amount of the Policy plus any positivevariable insurance amount in force. We adjust the DeathBenefit on each Policy Anniversary when we determine thevariable insurance amount for the following year. The totalDeath Benefit also includes the amount of insurance providedby any paid-up additions which you have purchased withdividends. The Death Benefit for a Whole Life Policy will notbe less than the face amount so long as you pay premiumswhen they are due. For a Single Premium Life Policy theDeath Benefit will not be less than the face amount. Theamount payable at death is reduced by the amount of anyPolicy Debt outstanding.

Paid-up additions you have purchased with dividends are notcounted for purposes of the guarantee that the Death Benefitof a Whole Life Policy or a Single Premium Life Policy willnever be less than the face amount of the Policy. If thevariable insurance amount is negative, the total Death Benefitwill be the guaranteed face amount plus the amount ofinsurance provided by any paid-up additions. Paid-upadditions are amounts of permanent insurance, paid for withdividends and added to a basic life insurance policy, and forwhich the premium for the entire lifetime of the Insured hasbeen paid. Paid-up additions have Cash Value and loan value.

Extra Ordinary Life Policy The Death Benefit for an ExtraOrdinary Life Policy is affected by the amount of Extra LifeProtection in force. Initially, the amount of Extra LifeProtection is 40% of the total amount of insurance and is inthe form of one year term insurance; the amount of terminsurance may be adjusted on each Policy Anniversary

thereafter. Term insurance is life insurance which pays aDeath Benefit only if the Insured dies during the term forwhich the insurance has been purchased. Term insurance isordinarily purchased on an annual basis at a cost which riseswith the increasing age of the Insured. It has no cash surrendervalue or loan value. The amount of term insurance included inExtra Life Protection affects the dividends payable on ExtraOrdinary Life Policies. Over time, positive variable insuranceamounts and paid-up additions purchased with dividends willreduce the one year term insurance portion of the Extra LifeProtection to an amount that (with variable insurance amountsand paid-up additions) will maintain the total Death Benefit atthe amount for which the Policy was issued. The terminsurance is eliminated at any time when the sum of positivevariable insurance amount plus the paid-up additions equals orexceeds the initial amount of Extra Life Protection.

The amount of Extra Life Protection may increase over timebut it will not decrease below the initial amount during thePolicy’s guaranteed period, so long as you pay premiumswhen they are due, all dividends are applied to purchasepaid-up additions and no paid-up additions are surrendered fortheir Cash Value. The length of the guaranteed period dependson the age of the Insured at issue. Please note that neither theactual investment results nor the dividends to be paid on thePolicy are guaranteed. You may request an in-forceillustration to illustrate the effect of various future rates ofreturn on the amount of Extra Life Protection.

After the guaranteed period expires, if the sum of positivevariable insurance amounts plus the paid-up additions is lessthan the initial amount of Extra Life Protection on any PolicyAnniversary, we may reduce the amount of your terminsurance for the Policy Year. We will give you notice of thereduction and you will have an opportunity to pay anadditional amount of premium in order to keep the initialamount of insurance in force. The maximum premium rate isset forth in the Policy. The maximum premium rate variesbetween $6.27 per $1,000 of term insurance and $1,000 per$1,000 of term insurance, depending on the age and sex of theinsured. Your right to continue the Extra Life Protection willterminate as of the first Policy Anniversary when you fail topay the additional premium when due.

The Death Benefit for an Extra Ordinary Life Policy is thesum of the Minimum Death Benefit plus the amount of ExtraLife Protection in force. The Minimum Death Benefit is 60%of the total amount of insurance for which the Policy wasissued. We guarantee the Minimum Death Benefit for thelifetime of the Insured so long as you pay premiums whenthey are due.

The total Death Benefit is not affected by either investmentresults or the amount of dividends paid, so long as the Policyis within the guaranteed period of Extra Life Protection unlessthe term insurance has been eliminated by positive variableinsurance amount and paid-up additions as described above.Good investment results and increases in dividends increasethe likelihood that the total Death Benefit will begin to risebefore the guaranteed period of Extra Life Protection expires.Adverse investment results or decreases in dividends could

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cause the total Death Benefit to fall below the amount ofinsurance which was initially in force, after the guaranteedperiod of Extra Life Protection expires, but it cannot fallbelow the Minimum Death Benefit so long as you paypremiums when they are due. In each case the amount payableat death is reduced by any Policy Debt outstanding.

The following three examples illustrate how Extra LifeProtection operates during the guaranteed period. In eachexample the Policy was issued for a total amount of $250,000.The minimum death benefit is $150,000 (60% of $250,000)and the initial amount of Extra Life Protection is $100,000(40% of $250,000).

• Example 1: On a Policy Anniversary, there is a totalpositive variable insurance amount of $10,000 and paid-upadditions are $15,000. The Extra Life Protection for thefollowing year would consist of term insurance in theamount of $75,000 ($100,000 minus the sum of $10,000and $15,000) in order to maintain the initial amount ofExtra Life Protection. There would be no effect on thecurrent Death Benefit because the total of the variableinsurance amount and paid-up additions has not exceededthe initial amount of Extra Life Protection.

• Example 2: On a Policy Anniversary, there is a totalnegative variable insurance amount of -$12,000 andpaid-up additions are $15,000. The Extra Life Protectionfor the following year would consist of term insurance inthe amount of $85,000, reflecting a reduction for paid-upadditions but not negative variable insurance amounts.Again, there would be no effect on the current DeathBenefit. In subsequent years positive variable insuranceamounts will need to make up for the negative variableinsurance amounts in order to affect the amount of terminsurance.

• Example 3: On a Policy Anniversary, there is a totalpositive variable insurance amount of $60,000 and paid-upadditions are $50,000. The Extra Life Protection for thefollowing year would consist of no term insurance andwould increase to $110,000 (the sum of $60,000 and$50,000). In this case the current Death Benefit wouldincrease to reflect variable insurance amounts and paid-upinsurance in excess of the Extra Life Protection (see“Variable Insurance Amount” above).

We have designed the Extra Ordinary Life Policy for apurchaser who intends to use all dividends to purchase paid-upadditions. If you use dividends for any other purpose, or if anypaid-up additions are surrendered for their Cash Value, theterm insurance in force will immediately terminate, anyremaining guaranteed period of Extra Life Protection willterminate and your right to continue the amount of Extra LifeProtection as described above will terminate. The amount ofExtra Life Protection thereafter will be the sum of positivevariable insurance amount plus any paid-up additions whichremain in force.

Cash Value

The Cash Value of a Policy is equal to the amount you areeligible to receive when you surrender the Policy. Ifinvestment results were a net level 4% every year, the Cash

Value would increase each year according to a table in yourPolicy (“tabular Cash Value”). However, the Cash Value forall Policies will change daily in response to investment results.For any given date, to calculate the Cash Value, the tabularCash Value for the last Policy Anniversary is adjusted toreflect the time elapsed since the last Policy Anniversary. Wethen adjust the sum of the tabular Cash Value and the netsingle premium for the variable insurance amount (see thediscussion of net single premiums under “Variable InsuranceAmount”) to reflect investment results from the last PolicyAnniversary to the date for which the calculation is beingmade. The Cash Value is increased by the value of anypaid-up additions which have been purchased with dividends.The value of the paid-up additions reflect investment resultsfrom your last Policy Anniversary to the date for which thecalculation is being made. If a portion of the premium for thecurrent Policy Year has not been paid, the Cash Value of aWhole Life Policy or an Extra Ordinary Life Policy will bereduced. The Cash Value for all Policies will be reduced byany Policy Debt outstanding. No minimum Cash Value isguaranteed.

We determine the Cash Value for a Policy at the end of eachvaluation period (typically, 4:00 p.m. Eastern Time eachbusiness day). Each business day, together with anynon-business days before it, is a valuation period. A businessday is any day on which the NYSE is open for trading. Inaccordance with the requirements of the 1940 Act, we mayalso determine the Cash Value for a Policy on any other dayon which there is sufficient trading in securities to materiallyaffect the value of the securities held by the Portfolios.

You may surrender a Policy for the Cash Value at any timeduring the lifetime of the Insured. We will surrender yourPolicy upon receiving a surrender request in Good Order atour Home Office. Requests for surrender received before theclose of trading (typically, 4:00 p.m. Eastern Time) on theNYSE are deemed to be received and effective that day. Ifreceived on or after the close of trading, requests are deemedto be received and effective as of the close of the next regulartrading session of the NYSE. If your request is not in GoodOrder, either we or your Financial Representative may notifyyou in writing, by telephone or by email in an effort toconform your request to our then-current requirements.Alternatively, you may use the Cash Value of a Whole LifePolicy or an Extra Ordinary Life Policy to provide extendedterm insurance or a reduced amount of fixed or variablepaid-up insurance. (See “Extended Term and Paid-UpInsurance”). Surrender proceeds may be paid under an IncomePlan requested by an Owner at the time of surrender.Available Income Plans include an interest income plan,installment income plans, and life income plans. TheCompany may offer additional Income Plans.

You may request a Death Benefit reduction, so long as thePolicy’s Death Benefit after reduction meets the regularminimum size requirements. A proportionate refund of thePolicy’s Cash Value will result from any Death Benefitreduction. The refund of Cash Value will first be appliedtoward any existing loan balance. The remainder of the Cash

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Value refunded will be returned to the Owner. The remainingPolicy will be based on the age and underwriting classificationof the Insured at the time of issuance of the original Policy.We will allocate reductions among the Divisions in proportionto the amounts in the Divisions.

Annual Dividends

The Policies are eligible to share in the divisible surplus, ifany, of the Company. Each year we determine, in our solediscretion, the amount and appropriate allocation of divisiblesurplus. Divisible surplus allocated to your Policy is referredto as a “dividend.” A Policy’s share, if any, will be credited asa dividend on the Policy Anniversary. We will not pay adividend on a Whole Life Policy or an Extra Ordinary LifePolicy which is in force as extended term insurance. There isno guaranteed method or formula for the determination orallocation of divisible surplus. The Company’s approach issubject to change. There is no guarantee of a divisible surplus.Even if there is a divisible surplus, the payment of a dividendon a Policy is not guaranteed. Illustrated dividends publishedat the time a life insurance policy is issued generally reflectthe actual recent experience of the issuing company withrespect to mortality and expenses and hypothetical investmentresults.

If you receive dividends, you may use them to purchasevariable paid-up additions, unless the Policy is in force asreduced fixed paid-up insurance. We will also pay dividendsin cash, or you may use them to pay premiums or leave themto accumulate with interest (see “Tax Consideration—TaxTreatment of Life Insurance”); but unless you use alldividends we pay on an Extra Ordinary Life Policy topurchase paid-up additions, the term insurance portion of theExtra Life Protection will be terminated. (See “Extra OrdinaryLife Policy”). We hold dividends you leave to accumulatewith interest in our General Account and we will credit themwith a rate of interest we determine annually. The interest ratewill not be less than an annual effective rate of 3.5%. If aWhole Life Policy or an Extra Ordinary Life Policy is in forceas reduced fixed benefit paid-up insurance, dividends may beused to purchase fixed benefit paid-up additions. (See“Extended Term and Paid-Up Insurance”). Dividends used topurchase variable benefit paid-up additions will be allocatedto the Divisions of the Separate Account according to theallocation of Net Premiums then in effect.

Policy Loans and Automatic Premium Loans

Described below are certain terms and conditions that applywhen you borrow amounts under the Policy. Policy loans aresecured by your Policy Value. For information on the taxtreatment of loans, see “Tax Considerations” and consult withyour tax advisor.

Policy Loans You may borrow an amount that, when addedto existing Policy Debt, is not more than the maximumamount under your policy (the “loan value”). The loan value is90% of the sum of the Cash Value and any existing PolicyDebt on the date of the loan. You may take loan proceeds incash or, for the Whole Life and Extra Ordinary Life Policies,

you may use them to pay premiums on the Policy. Wenormally pay the loan proceeds within seven days after wereceive a proper loan request at our Home Office. EligibleOwners may also submit loan requests via the Variable LifeService Center at 1-866-424-2609. Written and telephonerequests will be processed based on the date and time they arereceived in the Home Office, provided the request is receivedin Good Order. If your request is not in Good Order, either weor your Financial Representative may notify you in writing, bytelephone or by email in an effort to conform your request toour then-current requirements. Based on our administrativeprocedures, you may have the option of receiving funds viawire transfer or priority mail, and we may charge a fee for thisservice to cover our administrative costs. We may postponepayments of loans under certain conditions described in the“Deferral of Determination and Payment” section of thisprospectus. Under certain circumstances in accordance withour procedures your Financial Representative may provide uswith instructions regarding requests on your behalf.

Automatic Premium Loans If you have chosen theAutomatic Premium Loan provision or it is currently in effectfor your Policy, a premium loan, which is a form of Policyloan, will automatically be made to pay an overdue premiumif the premium is less than the maximum amount available fora new loan. A confirmation statement will be sent each timean automatic premium loan occurs.

General Loan Terms Interest on a loan accrues and ispayable on a daily basis. We add unpaid interest to the amountof the loan. The Policy’s Cash Value is reduced by the amountof the loan. If the Cash Value decreases to zero, the Policywill terminate unless a sufficient portion of the loan is repaid.We will send you a notice at least 31 days before thetermination date. The notice will show how much you mustrepay to keep the Policy in force.

You select the loan interest rate. The loan interest rate isapplied to both the amount of the loan and accrued interest. Aspecified annual effective rate of 8% is one choice. (Thespecified annual effective rate may be lower in Arkansas.) Theother choice is a variable rate based on a corporate bond yieldindex. We will adjust the variable rate annually. It will not beless than 5%.

We will take the amount of a loan, including interest as itaccrues, from the Divisions in proportion to the amounts in theDivisions. We will transfer the amounts withdrawn to ourGeneral Account and will credit those amounts on a dailybasis with an annual earnings rate equal to the loan interestrate less a charge for the mortality and expense risks we haveassumed and for expenses, including taxes. The aggregatecharge is currently at the annual rate of .85% for the 8%specified loan interest rate and .85% for the variable loaninterest rate. For example, the earnings rate corresponding toan 8% loan interest rate is currently 7.15%. A loan, even ifyou repay it, will have a permanent effect on the Policy’svariable insurance amount and Cash Value because theamounts you have borrowed will not participate in theSeparate Account’s investment results while the loan isoutstanding. The effect may be either favorable or unfavorable

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depending on whether the earnings rate credited to the loanamount is higher or lower than the investment performance ofthe unborrowed amounts left in the Divisions of the SeparateAccount.

The amount payable at death will also be reduced by theamount of any Policy Debt outstanding. If you surrender orexchange the Policy or allow it to lapse while Policy Debt isoutstanding, the amount of the loan, to the extent it has notpreviously been taxed, will be considered as an amount youreceived and taxed accordingly.

You may repay a loan, and any accrued interest outstanding,in whole or in part, at any time while the Insured is alive. Ifwe receive a payment without specific instructions, we willfirst apply the payment to any premium due, with anyremaining amount being applied to any outstanding loans.Payments in excess of outstanding debt and premiums duewill be returned unless such amounts are deemed to be deminimis according to our procedures. Except as describedbelow, if we receive your loan payments before the close oftrading (typically, 4:00 p.m. Eastern Time) on the NYSE, wewill credit payments as of the date we receive them andtransfer them from our General Account to the Divisions, inproportion to the amounts in the Divisions, as of the samedate. If we receive your loan payments on or after the close oftrading on the NYSE, we will credit payments as of the closeof the next regular trading session of the NYSE and transferthem from our General Account to the Divisions, inproportion to the amounts in the Divisions, as of the date wecredit the payment. Payments must be in Good Order to beprocessed. If your payment is not in Good Order, either we oryour Financial Representative may notify you in writing, bytelephone or by email in an effort to conform your payment toour then-current requirements.

Policy loan payments received within 34 days after the loaninterest billing date will be credited as of the loan interestbilling date. Automatic premium loans are effective as of thepremium due date unless a loan payment is received betweenthe premium due date and the date the Automatic PremiumLoan is made. Automatic premium loan payments received upto 66 days after the loan interest billing date will be creditedas of the Policy Anniversary, depending on your premiumpayment schedule. We will send you a notice indicating yourloan interest billing date. Loan repayments are not subject totransaction fees.

Extended Term and Paid-Up Insurance

If a premium for a Whole Life Policy or an Extra Ordinary LifePolicy is not paid when due or within the 31-day grace period(see “Grace Period”), and you have not chosen the AutomaticPremium Loan (APL) provision or do not have sufficient loanvalue to pay the premium, (see “Policy Loans and AutomaticPremium Loans”), the Cash Value will purchase extended terminsurance, or, at your request, a reduced amount of either fixedor variable benefit paid-up insurance.

If you use the Cash Value to provide a reduced amount offixed benefit paid-up insurance or for extended term

insurance, we will transfer the amount of the Cash Value fromthe Separate Account to our General Account at theconclusion of the 31 day grace period. Thereafter the Policywill not participate in the Separate Account’s investmentresults unless the Policy is subsequently reinstated. (See“Reinstatement”). You may select variable benefit paid-upinsurance only if the Policy has at least $1,000 of Cash Value.The minimum guaranteed death benefit (the face amount forWhole Life or the Minimum Death Benefit for Extra OrdinaryLife) is not in effect for variable paid-up insurance.

For fixed paid-up insurance, you must have selected paid-upinsurance within three months after the due date of your firstunpaid premium. We determine the amount of paid-upinsurance by the amount of Cash Value and the age and sex ofthe Insured, using the table of net single premiums at theAttained Age. Fixed benefit paid-up insurance has guaranteedcash and loan values. Paid-up insurance remains in force forthe lifetime of the Insured unless the Policy is surrendered orthe Cash Value is reduced to zero because of a Policy loan.

If the Policy remains in force as extended term insurance, theamount of insurance will equal the Death Benefit prior to thedate the premium was due, less any Policy Debt. The amountof Cash Value and the age and sex of the Insured willdetermine how long the insurance continues. We will, uponyour request, tell you the amount of insurance and how longthe term will be. Extended term insurance is not available ifthe Policy was issued with a higher premium for extramortality risk. Extended term insurance has a Cash Value butno loan value.

Reinstatement

If a premium for a Whole Life Policy or an Extra OrdinaryLife Policy is due and remains unpaid at the end of the graceperiod, the Policy will lapse. The Policy may be reinstatedafter lapse within five years after the premium due date. TheInsured must provide satisfactory evidence of insurability.Any premium or other payment due, including any applicableinterest, will also be required. If we approve your request forreinstatement and the request is received before the close oftrading (typically, 4:00 p.m. Eastern Time) on the NYSE, wewill deem your request to be received and effective that day. Ifwe receive your request on or after the close of trading on theNYSE, we will deem your request to be received and effectiveon the next regular trading session of the NYSE. Applicationsmust be received in Good Order to be processed. If yourrequest is not in Good Order, either we or your FinancialRepresentative may notify you in writing, by telephone or byemail in an effort to conform your request to our then-currentrequirements.

The Company may waive the requirement to providesatisfactory evidence of insurability if the reinstatement isapplied for, and any premium or other payment due is paid,within 90 days after the premium due date and while theInsured is alive. Upon reinstatement, your Policy Date will notchange. Therefore, fees and charges that vary by Policy yearwill take into account the period of time your Policy wasterminated. In addition, following the reinstatement the Policy

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will have the same Death Benefit and amount in each Divisionas if all premiums had been paid when due. We will make anadjustment for any Policy Debt or the debt may be reinstated.A reinstatement may have important tax consequences. If youcontemplate any such transaction you should consult aqualified tax adviser.

Reinvestments After Surrender

While Owners have no right to reinvestment after a surrender,we may, at our sole discretion, permit such reinvestments asdescribed in this paragraph. In special limited circumstances,we may allow payments into a Policy in the form of returnedsurrender proceeds in connection with a request to void asurrender if the request is received by the Company within areasonable time after the surrender proceeds are mailed. Thesepayments may be processed without a sales load in the case ofa Whole Life Policy or an Extra Ordinary Life Policy. Theperiod for which we will accept requests for the return ofsurrender proceeds after a surrender may vary in accordancewith our administrative procedures. The returned surrenderproceeds will be reinvested after our receipt of thereinvestment request in Good Order at our Home Office. If wereceive your request before the close of trading (typically,4:00 p.m. Eastern Time) on the NYSE, we will deem yourrequest to be received and effective that day. If we receiveyour request on or after the close of trading on the NYSE, wewill deem your request to be received and effective on thenext regular trading session of the NYSE. If your request isnot in Good Order, either we or your Financial Representativemay notify you in writing, by telephone or by email in aneffort to conform your request to our then-currentrequirements. Proceeds will be applied to the same Divisionfrom which the surrender was made. Under certaincircumstances in accordance with our procedures yourFinancial Representative may provide us with instructionsregarding requests for reinvestment on your behalf.

Depending on the Insured’s underwriting classification, wemay not accept the reinvestment or we may accept thereinvestment with different charges and expenses under thePolicy. We may refuse to process reinvestments where it is notadministratively feasible; including where any suchreinvestment may cause the Policy to fail to qualify as lifeinsurance under applicable law. Decisions regarding requestsfor reinvestment will take into consideration differences incosts and services and will not be unfairly discriminatory.Policies with reinvested surrender proceeds will have the sameDeath Benefit as if the proceeds had not been surrendered,except the values will reflect the fact that amounts were notinvested in the Separate Account during the period of time thesurrender proceeds were not in the Policy as well as anychanges in charges and expenses due to a change inunderwriting classification. We will make an adjustment forany Policy Debt or the debt may be reinstated.

Please note that our decision to permit a reinvestment does notreverse or eliminate any tax consequences and/or tax reportingresulting from the original surrender. Surrenders have taxconsequences and we may be required to report them to the

Internal Revenue Service and/or your state for income taxpurposes. We may also be required to treat the reinvestedproceeds as a new premium for purposes of determiningwhether your policy will become a MEC. (See “TaxConsiderations”).

Right to Exchange for a Fixed Benefit Policy

It is currently Company practice to allow you to exchangeyour Policy for a policy that does not vary with the investmentexperience of the Separate Account (“Fixed Benefit Policy”).We may modify or terminate this accommodation at any time,with or without notice, unless your state or the terms of yourPolicy provide for such an exchange. We may requireevidence of insurability. The Fixed Benefit Policy will be onthe life of the same Insured and at the time of the exchangewill have the same Policy Date and Issue Age and a DeathBenefit at least as great as the initial guaranteed Death Benefitof your Policy (assuming no reduction in Death Benefit priorto the exchange). The premiums and Cash Value will be thesame as those for fixed benefit policies that we issue on theissue date of the Fixed Benefit Policy. The exchange may besubject to an equitable cash adjustment, which will recognizethe investment performance of the Policy through the effectivedate of the exchange, and may have tax consequences. Anexchange will be effective when we receive a proper writtenrequest, as well as the Policy, and any amount due on theexchange.

In addition, you may exchange a Policy for a Fixed BenefitPolicy if, at any time, a Fund changes its investment adviser,if there is a material change in the investment objectives orrestrictions of a Portfolio, or a Portfolio is substituted foranother portfolio (see “Substitution of Portfolio Shares andOther Changes”). There may be a cost associated with theexchange. We will give you notice of any such change. Youmay make the change within 60 days after the notice oreffective date of the change, whichever is later.

Modifying a Policy

Any Policy change that you request is subject to our thencurrent insurability and processing requirements. Processingrequirements may include, for example, completion of certainforms and satisfying certain evidentiary requirements.

If the Policy is changed or modified, we may makeappropriate endorsements to the Policy, and we may requireyou to send your Policy to our Home Office for endorsement.Any modification or waiver of our rights or requirementsunder the Policy must be in writing and signed by an officer ofthe Company. No agent or other person may bind us bywaiving or changing any provision contained in the Policy.

Upon notice to you, we may modify a Policy:

• to conform the Policy, our operations, or the SeparateAccount’s operations to the requirements of any law(including any regulation issued by a government agency)to which the Policy, the Company, or the SeparateAccount is subject;

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• to ensure continued qualification of the Policy as a lifeinsurance contract under the federal tax laws; or

• to reflect a change in the Separate Account’s operation.

Other Policy Provisions

Owner The Owner is identified in the Policy. The Ownermay exercise all rights under the Policy while the Insured isliving. Ownership may be transferred to another. Writtenproof of the transfer must be received by Northwestern Mutualat its Home Office. In this prospectus “you” means the Ownerof a Policy. Generally, only Owners are entitled to importantinformation about the Policy. Other persons, such asbeneficiaries or payors, are entitled to only limitedinformation.

Beneficiary The beneficiary is the person to whom theDeath Benefit is payable. The beneficiary is named in theApplication. You may change the beneficiary in accordancewith the Policy provisions.

Incontestability We will not contest a Policy after it hasbeen in force during the lifetime of the Insured for two yearsfrom the Date of Issue or two years from the effective date ofa reinstatement. After the two year period, to the extentpermitted by state law we may rescind the Policy if theapplication contains a fraudulent misstatement.

Misstatement of Age or Sex If the age or sex of the Insuredhas been misstated, we will adjust benefits under a Policy toreflect the correct age and sex.

Collateral Assignment You may assign a Policy ascollateral security. We are not responsible for the validity oreffect of a collateral assignment and will not be deemed toknow of an assignment before receipt of the assignment inwriting at our Home Office.

Optional Benefits If available in your state, there are twooptional benefits available for purchase under the Whole LifePolicy or Extra Ordinary Life Policy: (1) a Waiver ofPremium Benefit; and (2) an Additional Purchase Benefit.

Subject to the terms and conditions of the benefit, the Waiverof Premium Benefit waives the payment of all premiums thatcome due during the total disability of the Insured if thedisability is due to accident or sickness and it begins on orbefore the Policy Anniversary nearest the Insured’s 60th

birthday. If the disability occurs after the Policy Anniversarynearest the Insured’s 60th birthday, the benefit waives thepayment of all premiums that come due during the totaldisability of the Insured until the Policy Anniversary nearestthe Insured’s 65th birthday.

Subject to the terms and conditions of the benefit, theAdditional Purchase Benefit guarantees the right to buy moreinsurance without proof of insurability.

If you selected one or both of these optional benefits, you aresubject to a separate charge. (See “Periodic Charges (Otherthan Fund Operating Expenses)” and “Deductions andCharges—Optional Benefits” for more information about thecharges.) Any charge will continue to be assessed as long as

the benefit remains in force. Once the Policy has been issued,an optional benefit may be issued only upon mutual agreement.

Income Plans The Policy provides a variety of IncomePlans for Policy benefits. Any Northwestern Mutual FinancialRepresentative authorized to sell the Policies can explain theseprovisions on request.

Deferral of Determination and Payment So long aspremiums have been paid when due, we will ordinarily payPolicy benefits within seven days after we receive all requireddocuments at our Home Office. However, we may deferdetermination and payment of benefits during any periodwhen it is not reasonably practicable to value securitiesbecause the NYSE is closed, or the SEC, by order, either hasdetermined that an emergency exists or permits deferral of thedetermination and payment of benefits for the protection ofOwners. If a Whole Life Policy or an Extra Ordinary LifePolicy is continued in force as extended term or reduced fixedbenefit paid-up insurance, we have the right to defer paymentof the Cash Value for up to six months from the date of aPolicy loan or surrender. If payment of surrender proceeds isdeferred for 30 days or more, we will pay interest at an annualeffective rate of 4%. If, under SEC rules, the GovernmentMoney Market Portfolio suspends payments of redemptionproceeds in connection with a liquidation of the Portfolio, wewill delay payment of any transfer, partial surrender,surrender, death benefit from the Government Money MarketDivision until the Portfolio is liquidated.

If you have submitted a check or draft to our Home Office, wehave the right to defer payment of surrender proceeds, CashValue resulting from a Death Benefit reduction, Death Benefitor loan proceeds or Income Plan benefits until the check ordraft has been honored.

If mandated under applicable law, we may be required toblock an Owner’s account and thereby refuse to pay anyrequests for transfer, Death Benefit reduction, surrender,loans, or Death Benefit proceeds, until instructions arereceived from the appropriate legal authority. We may also berequired to provide additional information about an Ownerand an Owner’s account to government authorities.

Voting RightsAs long as the Separate Account continues to be registered asa unit investment trust under the 1940 Act, and as long asSeparate Account assets of a particular Division are investedin shares of a given Portfolio, we will vote the shares of thatPortfolio held in the Separate Account in accordance withinstructions we receive from Owners. Periodic reports relatingto the Portfolios, proxy material, and a form on which one cangive instructions with respect to the proportion of shares of thePortfolio held in the Separate Account corresponding to theOwner’s Policy Value, will be made available to theOwner(s). We will vote shares for which no instructions havebeen received and shares held in our General Account in thesame proportion as the shares for which instructions have beenreceived from Owners. The effect of such proportional votingis that a small number of Owners may control the outcome ofa particular vote.

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Substitution of Portfolio Shares and Other Changes

If, in our judgment, one or more Portfolios become unsuitablefor continued use with the Policies because of a change ininvestment objectives or restrictions, for each such Portfoliowe may substitute shares of another Portfolio or anothermutual fund. Any substitution of shares will be subject to anyrequired approval of the SEC, the Wisconsin Commissioner ofInsurance or other regulatory authority. We have also reservedthe right, subject to applicable federal and state law, to operatethe Separate Account or any of its Divisions as a managementcompany under the 1940 Act, or in any other form permitted,or to terminate registration of the Separate Account ifregistration is no longer required, and to change the provisionsof the Policies to comply with any applicable laws.

Reports and Financial Statements

For each Policy Year you will receive a statement showing theDeath Benefit, Cash Value and any loans (including interestcharged) as of the Policy anniversary. We will also send you aconfirmation statement when you transfer among Divisions, takea Policy loan, or surrender the Policy. The annual statement andconfirmation statements will show your apportioned amountsamong the Divisions. If the Policy is in force as extended term orfixed benefit paid-up insurance, statements and reports will belimited to an annual Policy statement showing the Death Benefit,Cash Value and any loans.

Annually, we will send you a report containing financialstatements of the Separate Account and semi-annually, wewill send you reports containing financial information andschedules of investments for the Portfolios underlying theDivisions to which your Invested Assets are allocated. Thefinancial statements of the Company appear in the Statementof Additional Information. To receive a copy of the AnnualReport, Semi-Annual Report and/or the Statement ofAdditional Information, call the Variable Life Service Centerat 1-866-424-2609. Certain reports and other information canbe obtained on our website at www.northwesternmutual.com.

Special Policy for Employers

The premium for the standard Policy is based in part on thesex of the Insured. The standard annuity rates for IncomePlans which last for the lifetime of the payee are also based, inpart, on the sex of the payee. However, if your Policy wasissued in connection with an employer sponsored benefit planor arrangement, federal law and the laws of certain states mayrequire that premiums and annuity rates be determinedwithout regard to sex. You are urged to review any questionsin this area with qualified counsel.

Householding

To reduce costs, we may send only a single copy of the samedisclosure document(s) (such as prospectuses, prospectussupplements, reports, announcements, proxy statements,notices, and information statements) to each consentinghousehold (rather than sending copies to each Owner residingin a household). If you are or become a member of such a

household, you can revoke your consent to “householding” atany time, and can begin receiving your own copy of suchdisclosure documents, by calling the Variable Life ServiceCenter at 1-866-424-2609.

Abandoned Property RequirementsEvery state has unclaimed property laws which generallydeclare insurance contracts/policies to be abandoned after aperiod of inactivity of three to five years from the contract’s/policy’s maturity date, the date the death benefit is due andpayable, or in some states, the date the insurer learns of thedeath of the insured. For example, if the payment of the deathbenefit has been triggered, but, if after a thorough search, weare still unable to locate the beneficiary, or if the beneficiarydoes not come forward to claim the death benefit proceeds in atimely manner, the death benefit proceeds will be paid to theabandoned property division or unclaimed property office ofthe state in which the beneficiary or you last resided, as shownon our books and records, or to our state of domicile. This“escheatment” is revocable, however, and the state isobligated to pay the death benefit proceeds (without interest)if your beneficiary steps forward to claim it with the properdocumentation. To prevent such escheatment, it is importantthat you update your beneficiary designations, includingaddresses, if and as they change. Please contact your FinancialRepresentative or call the Variable Life Service Center at1-866-424-2609 for assistance in making such changes.

CybersecurityThe Company has administrative, technical and physicalsafeguards in place with respect to information security,nevertheless, our variable product business is potentiallysusceptible to operational and information security risks resultingfrom a cyber-attack as it is highly dependent upon the effectiveoperation of our computer systems and those of our businesspartners. These risks include, among other things, the theft,misuse, corruption and destruction of data maintained online ordigitally, denial of service on websites and other operationaldisruption and unauthorized release of confidential customerinformation. Cyber-attacks affecting us, the Portfolios,intermediaries and other affiliated or third-party service providersmay adversely affect us and your Policy Value. For instance,cyber-attacks may interfere with our processing of contracttransactions (including the processing of orders through ourwebsite, if available, or with the Portfolios), impact our ability tocalculate values, cause the release and possible destruction ofconfidential customer or business information, impede orderprocessing, subject us and/or our service providers andintermediaries to regulatory fines and financial losses and/orcause reputational damage. Cybersecurity risks may also impactthe issuers of securities in which the Portfolios invest, which maycause the Portfolios to lose value. There can be no assurance thatwe or the Portfolios or our service providers will avoid lossesaffecting your Policy due to cyber-attacks or information securitybreaches in the future.

Legal ProceedingsNorthwestern Mutual, like other life insurance companies, isgenerally involved in litigation at any given time. Although

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the outcome of any litigation cannot be predicted withcertainty, we believe that, as of the date of this prospectus,there are no pending or threatened lawsuits that will have amaterially adverse impact on the ability of NorthwesternMutual to meet its obligations under the Policy, on theSeparate Account, or on Northwestern Mutual InvestmentServices, LLC, the principal underwriter for the SeparateAccount, and its ability to perform its duties as underwriter forthe Separate Account.

Speculative Investing

This Policy, or any of its riders, should not be used for anytype of speculative collective investment scheme (including,for example, arbitrage). Your Policy is not intended to betraded on any stock exchange or secondary market, andattempts to engage in such trading may violate state and/orfederal law.

Owner Inquiries

You may receive information about your Policy via theVariable Life Service Center by calling toll-free at1-866-424-2609. With your User ID and password, you canalso visit our website www.northwesternmutual.com to accessperformance information, forms for routine service, and dailyPolicy values for Policies you own. Eligible Owners may alsoset up certain electronic payments, transfer accumulatedamounts among Divisions and change the allocation of futurecontributions online, subject to our administrative procedures.For enrollment information, please visit our websitewww.northwesternmutual.com. Please note that electronicdevices may not always be available. Any electronic device,whether it is yours, your service provider’s, your agent’s orours, can experience outages or slowdowns for a variety ofreasons, which may delay or prevent our

processing of your request or payment. Although we havetaken precautions to limit these problems, we cannot promisecomplete reliability under all circumstances. If you areexperiencing problems, you should make your request orpayment in writing at our Home Office. Electronic requests orpayments are deemed to be received by us upon receipt at theelectronic location designated by us in our procedures. If youhave questions about surrendering your Policy, please callyour Financial Representative or the Variable Life ServiceCenter at 1-866-424-2609. To file a claim, please call yourFinancial Representative or Life Benefits at 1-800-635-8855.

Illustrations

Your Northwestern Mutual Financial Representative willprovide you with an illustration for your Policy upon request.The illustration will reflect the performance of your Policy todate and will show how the amount payable at death and CashValue would vary based on hypothetical future investmentresults.

Illustrations for variable life insurance policies do not projector predict investment results. The illustrated values assumethat non-guaranteed elements such as dividends, policycharges and level investment returns will not change. Giventhe volatility of the securities markets over time, the illustratedscenario is unlikely to occur and the Policy’s actual CashValue, amount payable at death, and certain expenses (whichwill vary with the investment performance of the Portfolios)will be more or less than those illustrated. In addition, theactual timing and amounts of payments, deductions, expensesand any values removed from the policy will also impactproduct performance. Due to these variations, even a Portfoliothat averaged the same return as illustrated will producevalues which will be more or less than those which wereillustrated.

Tax ConsiderationsGeneral The following discussion provides a generaldescription of federal tax considerations relating to yourPolicy. The discussion is based on current provisions of theInternal Revenue Code (“Code”) as currently interpreted bythe Treasury Department and the Internal Revenue Service(“IRS”). The discussion is not exhaustive, it does not addressthe likelihood of future changes in federal tax law orinterpretations thereof, and it does not address state or localtax considerations which may be significant in the purchaseand ownership of a Policy.

Depending on the circumstances, the exchange of a Policy, aPolicy loan (including the addition of unpaid loan interest to aPolicy loan), or a change in ownership or an assignment of thePolicy may have federal income tax consequences. Inaddition, federal, state and local transfer, estate, inheritance,and other tax consequences of Policy ownership, premiumpayments and receipt of Policy proceeds depend on thecircumstances of each Owner or beneficiary. If youcontemplate any such transaction you should consult aqualified tax adviser.

This tax discussion is intended to describe the tax consequencesassociated with your Policy. It does not constitute legal or taxadvice, and is not intended to be used and cannot be used toavoid any penalties that may be imposed on a taxpayer.Taxpayers should seek advice based on their particularcircumstances from an independent tax advisor.

Life Insurance Qualification Section 7702 of the Codedefines life insurance for federal income tax purposes. UnderSection 7702, a Policy will generally be treated as life insurancefor federal tax purposes if at all times it meets either a guidelinepremium test or a cash value accumulation test. We havedesigned your Policy to comply with only the cash valueaccumulation test. We may take any action that may be necessaryfor the Policy to qualify as life insurance for tax purposes.

The definitional tests under the Code are based on theCommissioner’s Standard Ordinary (CSO) mortality tables ineffect when the Policies were issued. For Policies issued ormaterially changed after 2008, the tests must be based on the

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2001 CSO mortality tables. Because Policies issued based onthe 1980 CSO mortality tables may not satisfy the definitionaltests using the 2001 CSO mortality tables, certain changes tothose Policies will not be permitted (as defined by IRSNotices 2004-61 and 2006-95). Special safe harbor calculationrules apply to life insurance after the Insured attains age 100.See IRS Rev. Proc. 2010-28.

As provided by Section 817(h) of the Code, the Secretary ofthe Treasury has set standards for diversification of theinvestments underlying variable life insurance policies.Failure to meet the diversification requirements woulddisqualify your Policy as life insurance for purposes ofSection 7702 of the Code. We believe that your Policycomplies with the provisions of Sections 7702 and 817(h) ofthe Code, but the application of these rules is not entirelyclear. We may make changes to your Policy if necessary forthe Policy to qualify as life insurance for tax purposes.

IRS Rev. Ruls. 2003-91 and 2003-92 provide guidance onwhen an Owner’s control of Separate Account assets willcause the Owner, and not the life insurance company, to betreated as the owner of those assets. Important indicators ofinvestor control are the ability of the Owner to select theinvestment advisor, the investment strategy or the particularinvestments of the Separate Account. If the Owner of a Policywere treated as the owner of the assets held in the SeparateAccount, the income and gains related to those assets wouldbe included in the Owner’s gross income for federal incometax purposes. We believe that we own the assets of theSeparate Account under current federal income tax law.

Tax Treatment of Life Insurance While your Policy is inforce, increases due to investment experience are not subjectto federal income tax until there is a distribution as defined bythe Code. Death Benefit proceeds received by a beneficiarywill generally not be subject to federal income tax.

So long as your Policy is not classified as a MEC (see“Modified Endowment Contract”), the proceeds from asurrender or withdrawal will generally be taxable only to theextent that the proceeds exceed the basis of the Policy. Thebasis of the Policy is generally equal to the premiums paid lessany amounts previously received as tax-free distributions.Dividends paid in cash, if any, are generally taxed aswithdrawals with a resulting reduction in basis. However,dividends applied to purchase additional insurance or used topay premiums are generally not taxable. In certaincircumstances, a withdrawal of Cash Value during the first 15Policy Years may be taxable to the extent that the Cash Valueexceeds the basis of the Policy. This means that the amountwithdrawn may be taxable even if that amount is less than thebasis of the Policy.

Unless the Policy is a MEC, a loan received under your Policywill not be treated as a distribution subject to current federalincome tax. If the Policy remains in force until the death of theInsured or, in the case of joint life insurance, the second death,the Policy Debt will be repaid from the Death Benefit.However, if the Policy terminates by any method other thandeath, the Policy Debt will be repaid from the Cash Value of

the Policy, and the total Cash Value, including the totalamount of the Policy Debt, will be taxable to the extent itexceeds the basis of the Policy. If the extended term insurancenonforfeiture option is available in your Policy, and it lapsesto extended term insurance, the Policy Debt will be repaidfrom Cash Value of the Policy and the Policy Debt repaymentwill be treated as income and taxable to the extent it exceedsPolicy’s basis.

Caution must be used when taking cash out of a Policythrough policy loans. If interest is not paid annually, it isadded to the principal amount and the total Policy Debt willcontinue to increase for as long as the loan is maintained onthe Policy. In extreme situations, Owners can face what iscalled the “surrender squeeze.” The surrender squeeze occursif the Policy Debt becomes too large when compared to theunborrowed Cash Value remaining in the Policy, therebycausing the Policy to lapse. (See the “Policy Loans andAutomatic Premium Loans” section for more details). Asdescribed above, if your policy lapses with outstanding PolicyDebt, you will have an income tax liability to the extent thePolicy Debt exceeds the Policy basis. This means that youmay have to pay income tax for a year in which you did notreceive any cash from the policy.

Interest paid by individual Owners of a Policy will ordinarilynot be deductible. You should consult a qualified tax advisoras to the deductibility of interest paid, or accrued, by businessOwners of a Policy. (See “Business-Owned Life Insurance”).

Subject to the agreement of the Company, and the Ownermeeting any conditions set by the Company, a Policy may beexchanged tax-free for another life insurance policy coveringthe same Insured (or, in the case of joint life insurance,covering the Insureds or a surviving Insured) or an annuitycontract with the same owner (or, in the case of an annuityowned by a non-natural owner, if the annuitant is the same asthe life insurance policy insured). The Code also allowscertain policies to be exchanged for stand-alone andcombination long-term care policies on a tax-free basis.Policies that are exchanged for life insurance policies after2008 may only be exchanged for life insurance policies using2001 CSO mortality tables. Any cash received or loan repaidin an exchange will be taxed to the extent of the gain in thePolicy (i.e., on gain-first basis).

Ownership of a Policy may be transferred to a new owner. Ifthe transfer is a sale, it is taxable to the extent the salesproceeds exceed the basis of the Policy. The transfer of aPolicy with a loan in excess of Policy basis is considered asale to the extent of the loan, and the loan is treated as “salesproceeds” paid to the transferor. In Rev. Rul. 2009-13, the IRSruled that, when a life insurance policy is sold to a person withno insurable interest in the insured, the taxable gain iscalculated by reducing the basis of the policy by the annualcost of the insurance protection provided by the policy Thedeath benefit of a policy that was previously sold or otherwisetransferred for valuable consideration is taxable as ordinaryincome to the extent it exceeds the sum of the purchase priceand subsequent premiums paid by the new owner. However,the death benefit will not be taxable if the new owner is the

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insured, a partner of the insured, a partnership in which theinsured is a partner or a corporation in which the insured is ashareholder or officer or the basis of the Policy is carried over,in whole or in part, in the transfer. You should seek qualifiedtax advice if you plan a transfer of ownership.

Where the Policy cash value is distributed as periodicpayments under a payment plan, part or all of the taxablepayments may be subject to an additional 3.8% Medicare tax.The tax will be assessed on the Owner’s net investmentincome for the year to the extent that the Owner’s adjustedgross income (with slight modifications) exceeds $250,000(married filing jointly or surviving spouse), $125,000 (marriedfiling separately) or $200,000 (other filers) (not indexed)Under final regulations issued by the IRS, “net investmentincome” may include among other things the transfer of a lifeinsurance policy that constitutes a sale, interest paid on theDeath Benefit and taxable distributions from life insurancepolicies held in arrangements that constitute “passiveactivities”. You should seek qualified tax advice.

Modified Endowment Contracts (MEC) A modifiedendowment contract (“MEC”) is a type of life insurancecontract that is taxed less favorably on lifetime distributionsthan other life insurance contracts. A MEC has less favorabletax treatment because it is considered to be too investmentoriented. Generally, a Policy may be classified as a MEC if thecumulative premiums paid during the first seven Policy Yearsafter issue, or after a “material change” (described below),exceed the policy’s “seven-pay” limit. The seven-year timeperiod is commonly referred to as the “seven-pay period”. CodeSection 7702A defines the seven-pay limit as the sum of thepremiums (net of expense and administrative charges) thatwould have to be paid in order for the Policy to be fully paid-upafter seven level annual payments based on defined interest andmortality assumptions. If premiums in excess of the seven-paylimit are paid during a seven-pay period, a Policy will be aMEC. However, a policy will not be a MEC if the excesspremiums are refunded, with interest, within 60 days after theend of the Policy Year in which they are paid. For purposes ofmeasuring this 60-day refund period, the term “Policy Year”refers to the year that starts on the date of a material change ifthat date is different than the Policy Date. If excess premium isrefunded, all Policy values are recalculated as though the excesspremium had never been paid.

A policy can also become a MEC if the benefits under thePolicy are reduced during the seven-pay period or, in the caseof joint life Policies, the lifetime of either Insured. If areduction occurs during a seven-pay period, the seven-paypremium limit will be redetermined based on the reduced levelof benefits. All premiums paid during the seven-pay periodmust be retroactively tested against the new, lower, seven-paylimit. If the premiums previously paid are greater than therecalculated seven-pay premium level limit, the Policy willbecome a MEC. This means that a reduction of Policy benefitscan result in a MEC because of premiums paid in prior yearseven if those premiums did not exceed the policy’s seven-paylimit at the time they were paid. A reduction in benefitsincludes a decrease in the amount of coverage, the termination

or reduction of certain riders, a withdrawal or any other actionresulting in a surrender of Cash Value to you according to theterms of the Policy, an election of the paid-up option or, insome cases, a lapsing of the Policy where the Policy is notreinstated within 90 days. A life insurance policy which isreceived in exchange for a MEC will also be considered aMEC. In the case of joint life Policies, the reduction test mustbe applied during the lifetime of either Insured rather thanonly during seven-pay periods.

Whenever there is a “material change” under a Policy, it willgenerally be treated as a new contract for purposes ofdetermining whether the Policy is a MEC. This means that anew seven-pay period begins with a new seven-pay limit. Thenew seven-pay limit is determined by taking into account thevalue of the Policy at the time of such change. A materialchange could occur as a result of certain changes to thebenefits or terms of the Policy, such as a change in a deathbenefit option or a change in the Insured(s), if allowable underyour Policy. A material change could occur as a result of anincrease in the death benefit, the addition of a benefit or thepayment of a premium after the seven-pay period, whichcould be considered “unnecessary” under the Code.

If a Policy is a MEC, any distribution from the Policy will betreated as a distribution of gain first, subject to ordinaryincome taxation. Distributions for this purpose include a loana withdrawal of Cash Value, a surrender of the Policy, anddividends paid in cash. Distributions taken within the two-yearperiod prior to the Policy becoming a MEC may also be taxedunder the MEC tax rules. The Policy basis is increased to theextent a loan is a taxable distribution from a MEC. For thesepurposes, the term “loan”, includes an increase in Policy Debtdue to accrued but unpaid loan interest, or an assignment orpledge of the policy to secure a loan. For purposes ofdetermining the taxable portion of any distribution, all MECsissued by Northwestern Mutual to the same Owner (excludingcertain qualified plans) during any calendar year are to beaggregated. The Secretary of the Treasury has authority toprescribe additional rules to prevent avoidance of gain-firsttaxation on distributions from MECs.

A 10% penalty tax will apply to the taxable portion of adistribution from a MEC. The penalty tax will not, however,apply to distributions (i) to taxpayers 591⁄2 years of age orolder, (ii) in the case of a disability (as defined in the Code) or(iii) received as part of a series of substantially equal periodicannuity payments for the life (or life expectancy) of thetaxpayer or the joint lives (or joint life expectancies) of thetaxpayer and the taxpayer’s beneficiaries. The exceptionsgenerally do not apply to life insurance policies owned bycorporations or other entities.

Estate and Generation Skipping Taxes If the Insuredowns, or has any incidents of ownership in, the Policy, theamount of the Death Benefit will generally be includible in theInsured’s estate for federal estate tax purposes and anyapplicable state inheritance tax. If a Policy is a joint lifePolicy, the Death Benefit will be includible in the estate of thesecond to die if that that individual owned or had anyincidents of ownership in, the policy at the time of death. In

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some circumstances, the Death Benefit of a policy may beincluded in an Insured’s estate even if not owned at the timeof death. This may occur if the Insured transferred anownership interest, or an incident of ownership, in a policywithin three years of death. If the Owner dies, but an Insuredis still alive, the fair market value of the Policy will beincludible in the Owner’s estate. With appropriate estateplanning, A unlimited marital deduction may permit deferralof federal estate and gift taxes until the death of the Owner’ssurviving spouse.

If ownership of a Policy is transferred, either directly or intrust, to a person two or more generations younger than theOwner, the value of the Policy may be subject to a generationskipping transfer tax.

An exemption limit of $5 million (single)/$10 million(married) (with inflation indexing after 2011) and a maximumrate of 40% applies for purposes of the estate, gift andgeneration skipping transfer taxes. In addition, any unusedestate exemption limit may be carried over to the survivingspouse.

Business-Owned Life Insurance Business-owned lifeinsurance may be subject to certain additional rules.Section 101(j) of the Code provides that a portion of the DeathBenefit payable under business-owned life insurance in whichthe business is also the beneficiary will be taxable to theextent it exceeds the premiums or other consideration thebusiness paid for the policy. This rule will not apply if (i) theInsured is an eligible employee and (ii) certain notice andconsent requirements are satisfied before the policy is issued.Generally, an eligible employee is someone who was anemployee at any time during the 12-month period beforedeath, a director, a person who owns more than 5% of thebusiness, an employee earning more than $120,000 annually(increased for cost of living), one of the highest 5 paid officersor an employee who is among the highest paid 35% ofemployees. The law also imposes an annual reporting andrecord-keeping obligation on the employer. Increases inPolicy or Cash Value may also be subject to tax under thecorporation alternative minimum tax provisions.

Section 264(a)(1) of the Code generally disallows a deductionfor premiums paid on Policies by anyone who is directly orindirectly a beneficiary under the Policy. Interest on debt thatis related to or is incurred to purchase or carry life insurancemight be deductible in certain, limited, circumstances set forthin Code Section 264. For example, interest paid or accrued forup to an aggregate of $50,000 of indebtedness with respect tolife insurance covering a “key person” may be deductible.Generally, a key person is defined as an officer or a 20%owner. However, the number of key persons will be limited tothe greater of (a) five individuals, or (b) the lesser of 5% ofthe total officers and employees of the taxpayer or 20individuals. Deductible interest for these Policies will besubject to limits based on current market rates.

In addition, if a business owns life insurance with cash value,section 264(f) of the Code may disallow a portion of abusiness’s non-life insurance related interest deduction. Thedisallowance is based on a ratio that compares the amount of

unborrowed life insurance Cash Value to the adjusted basis ofother business assets. Certain policies may be excluded thedisallowance calculation. These include policies held bynatural persons unless the business is a direct or indirectbeneficiary under the policy and policies owned by a businessand insuring an individual who at the time the policy is issuedis an employee, director, officer or 20% owner (as well asjoint policies insuring 20% owners and their spouses). TheIRS has ruled that a policy received in a tax-free exchange isnewly issued for this purpose.

The IRS has ruled privately that losses in business-owned lifeinsurance could be deducted upon the surrender of the policyif there was no reasonable prospect of recovery, but that thelosses would be calculated by reducing the basis of the policyby the annual cost of the insurance protection provided by thepolicy. Private rulings apply only to the taxpayer who receivesthe ruling but may be indicative of the IRS’s thinking on anissue.

Special rules under the Code govern how life insurancecompanies calculate income tax deductions. Under these rulesthe annual increase in the cash value of life insurance policiesowned by life insurance companies may limit the company’sdeductions, resulting in an overall increase in its taxableincome. In Revenue Procedure 2007-61, the IRS provided asafe harbor under which the annual increase in cash value oflife insurance policies covering no more than 35% of thecompany’s employees, directors, officers and 20% ownerswill not limit the life insurance company’s deductions.Additionally, the Revenue Procedure included language thatthe tax-deferred nature of such contracts remains subject tochallenge by the IRS under other provisions of the tax law,including judicial doctrines such as the business purposedoctrine.

Policy Split Right If your Policy is a joint life Policy, yourPolicy permits the Owner to exchange the Policy for twopolicies, one on the life of each Insured, without evidence ofinsurability, if a change in the federal estate tax law results ineither the repeal of the unlimited marital deduction or a 50%or greater reduction in the maximum estate tax rate set forth inthe law. The exchange must be made while both Insureds arealive (and neither Insured is classified as a Joint Insurable).The request for exchange must be received no later than 180days after the earlier of the enactment of the law repealing theunlimited marital deduction or the enactment of the lawreducing the estate tax rate by at least 50%.

The IRS has ruled with respect to one taxpayer that such atransaction would be treated as a non-taxable exchange. If notso treated, such a split of the Policy could result in therecognition of taxable income.

Split Dollar Arrangements Life insurance purchased undera split dollar arrangement is subject to special tax rules.Treasury regulations regarding the taxation of split dollararrangements apply only to arrangements entered into ormaterially changed after September 17, 2003. The regulationsprovide that such split dollar arrangements must be taxedunder one of two mutually exclusive tax regimes dependingon the ownership of the underlying life insurance policy.

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Collateral assignment split dollar arrangements, in which theemployee owns the policy, must be taxed under a loan regime.Where such an arrangement imposes a below market interestrate or no interest rate, the employee is taxed on the imputedinterest under Section 7872 of the Code. Endorsement splitdollar arrangements, in which the employer owns the policy,must be taxed under an economic benefit regime. Under thisregime, the employee is taxed each year on (i) the value of thecurrent life insurance protection provided to the employee,(ii) the increase in the amount of policy Cash Value to whichthe employee has current access, and (iii) the value of anyother economic benefits provided to the employee during thetaxable year.

Under the Sarbanes-Oxley Act of 2002, it is a criminal offensefor an employer with publicly traded stock to extend orarrange a personal loan to a director or executive officer afterJuly 30, 2002. One issue that has not been clarified is whethereach premium paid by such an employer under a split dollararrangement with a director or executive officer is a personalloan subject to the new law.

Section 409A of the Code imposes requirements fornonqualified deferred compensation plans with regard to thetiming of deferrals, distribution triggers, funding mechanismsand reporting requirements. Nonqualified deferredcompensation plans that fail to meet these conditions are taxedcurrently on all compensation previously deferred and interestearned thereon and assessed an additional 20% penalty. Thelaw does not limit the use of life insurance as an informalfunding mechanism for nonqualified deferred compensationplans, but IRS Notice 2007-34 treats certain split dollararrangements as nonqualified deferred compensation plansthat must comply with the new rules. The effective date ofthese rules was December 31, 2008. Congress has alsoconsidered limiting an individual’s annual aggregate deferralsto a nonqualified deferred compensation plan to $1,000,000.

Valuation of Life Insurance Special valuation rules applyto life insurance contracts distributed from a qualified plan toa participant or transferred by an employer to an employee.IRS Rev. Proc. 2005-25 provides safe harbor formulas forvaluing variable and non-variable life insurance policies.Generally, the safe harbor value is the greater of (i) the sum ofthe interpolated terminal reserve, any unearned premiums, anda pro rata portion of the estimated dividends for the PolicyYear; or (ii) the cash value without reduction for anysurrender charges (but adjusted by a surrender factor forpolicies distributed from qualified plans) multiplied by afactor specified in Rev. Proc. 2005-25. These rules do notapply to split dollar arrangements entered into on or beforeSeptember 17, 2003 and not materially modified thereafter.

Other Tax Considerations Under Code Section 6011,taxpayers are required to annually report all “reportabletransactions”. Regulations under Code Section 6011 provide alist of several types of reportable transactions, some of whichmay involve life insurance policies. For example, in somecircumstances a reportable transaction might exist if lifeinsurance is owned by a welfare benefit plan. “Reportabletransactions” also include transactions that create significantdifferences between the amount of any item for purposes ofdetermining income, gain, expense or loss for tax purposesdiffers by more than $10 million, on a gross basis, from theamount of the item for purposes for book purposes. However,Rev. Proc. 2004-67 held that the purchase of life insurancepolicies that creates such a difference does not, by itself,constitute a “reportable transaction.” The rules related toreportable transactions are complicated and you shouldconsult a qualified tax advisor before purchasing anyinsurance policy as part of a transaction.

Distribution of the PolicyWe sell the Policy through our Financial Representatives whoalso are registered representatives of Northwestern MutualInvestment Services, LLC (“NMIS”). NMIS, our wholly-owned company, w as organized under Wisconsin law in 1998and is located at 611 East Wisconsin Avenue, Milwaukee,Wisconsin 53202. NMIS is a registered broker-dealer underthe Securities Exchange Act of 1934 and is a member of theFinancial Industry Regulatory Authority. NMIS is theprincipal underwriter and distributor of the Policy and hasentered into a Distribution Agreement with us.

Northwestern Mutual variable insurance and annuity productsare available exclusively through NMIS and its registeredrepresentatives and cannot be held with or transferred to anunaffiliated broker-dealer. Except in limited circumstances,NMIS registered representatives are required to offerNorthwestern Mutual variable insurance and annuity products.The amount and timing of sales compensation paid byinsurance companies varies. The commissions, benefits, and

other sales compensation that NMIS and its registeredrepresentatives receive for the sale of a Northwestern Mutualvariable insurance or annuity product might be more or lessthan that received for the sale of a comparable product fromanother company.

The maximum commission payable to the registeredrepresentative who sold the Whole Life or Extra Ordinary LifePolicy is 55% of the premium during the first Policy Year; 9%of the premium in Policy Years 2-3; 6% of the premium inPolicy Years 4-7; 3% of the premium in Policy Years 8-10;and 2% of Premium Payments thereafter. For the SinglePremium Life Policy, commissions were 2.75% of thepremium. Registered representatives may receive less than themaximum commission or no commission in certaincircumstances according to pre-established guidelines. Wemay also pay new registered representatives differently duringa training period. The entire amount of sales commissionspaid to registered representatives is passed through NMIS to

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the registered representative who sold the Policy and to his orher managers. The Company pays compensation and bonusesfor the management team of NMIS, and other expenses ofdistributing the Policies.

Because registered representatives of NMIS are also ourappointed agents, they may be eligible for various cashbenefits, such as bonuses, insurance benefits, retirementbenefits, and non-cash compensation programs that we offer,such as conferences, achievement recognition, prizes, andawards. In addition, registered representatives of NMIS whomeet certain productivity, persistency, and length of servicestandards and/or their managers may be eligible for additionalcompensation. For example, registered representatives whomeet certain annual sales production requirements withrespect to their sales of Northwestern Mutual insurance andannuity products may qualify to receive additional cash

compensation for their other sales of investment products andservices. Sales of the Policies may help registeredrepresentatives and/or their managers qualify for suchcompensation and benefits. Certain registered representativesof NMIS may receive other payments from us for therecruitment, training, development, and supervision offinancial representatives, production of promotional literatureand similar services.

Commissions and other incentives and payments describedabove are not charged directly to Owners or to the SeparateAccount. We intend to recoup commissions and other salesexpenses through fees and charges deducted under the Policy.NMIS registered representatives receive ongoing servicingcompensation related to the Policies, but may be ineligible toreceive ongoing servicing compensation paid by issuers ofother investment products for certain smaller accounts.

Glossary of TermsAPPLICATIONThe form completed by the applicant when applying forcoverage under the Policy. This includes any:1. amendments or endorsements;2. supplemental Applications;3. reinstatement Applications; and4. Policy change Applications.

ATTAINED AGEThe Insured’s Issue Age listed in the Policy, plus the numberof complete Policy Years that have elapsed since the PolicyDate.

CASH VALUEThe amount available in cash if the Policy is surrendered.

DATE OF ISSUEThe date on which insurance coverage takes effect as shown inthe Policy.

DEATH BENEFITThe gross amount payable to the beneficiary upon the death ofthe Insured, before the deduction of Policy Debt and otheradjustments.

DIVISIONA subdivision of the Separate Account. We invest eachDivision’s assets exclusively in shares of one Portfolio.

FINANCIAL REPRESENTATIVEAn individual who is authorized to sell you the Policy andwho is both licensed as a Northwestern Mutual insuranceagent and registered as a representative of our affiliate,Northwestern Mutual Investment Services, LLC, the principalunderwriter of the Policy.

FUNDEach Fund is registered under the 1940 Act as an open-endmanagement investment company or as a unit investmenttrust, or is not required to be registered under the Act. EachPortfolio of the Funds is available as an investment option

under the Policy. The assets of each of the Divisions of theSeparate Account are used to purchase shares of thecorresponding Portfolio of a Fund.

GENERAL ACCOUNTAll assets of the Company, other than those held in theSeparate Account or in other separate accounts that have beenor may be established by the Company.

GOOD ORDERYour request or payment meets all the current requirementsnecessary for us to process it. For certain requests this mayinclude, as applicable, the return of proceeds, evidence ofinsurability, underwriting, MEC-limit (or insurancequalification) requirements, any premium payments due,instructions as to payment due dates, or proper completion ofcertain Northwestern Mutual forms.

HOME OFFICEOur office at 720 East Wisconsin Avenue, Milwaukee,Wisconsin 53202-4797.

INCOME PLANAn optional method of receiving the Death Benefit, maturitybenefit, surrender proceeds or withdrawal proceeds of aninsurance policy or annuity contract through a series ofperiodic payments. An Income Plan may also be known as a“payment plan.”

INSUREDThe person named as the Insured on the Application and in thePolicy.

INVESTED ASSETSThe sum of all amounts in the Divisions of the SeparateAccount.

ISSUE AGEThe Insured’s age on his or her birthday nearest the PolicyDate.

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MECModified endowment contract as described in Section 7702Aof the Internal Revenue Code. A modified endowmentcontract is a life insurance contract that is considered tooinvestment oriented and is taxed less favorably on lifetimedistributions than other life insurance contracts. See the “TaxConsiderations” section for more detailed information.

NET PREMIUMThe amount of Premium Payment remaining after Premiumcharges have been deducted.

NYSENew York Stock Exchange.

OWNER (You, Your)The person named in the Application as the Owner, or theperson who becomes Owner of a Policy by transfer orsuccession.

POLICY ANNIVERSARYThe same day and month as the Policy Date in each yearfollowing the first Policy Year.

POLICY DATEThe date shown in the Policy from which the following arecomputed, among other things:1. Policy Year;2. Policy Anniversary;

3. the Issue Age of Insured; and4. the Attained Age of the Insured.

POLICY DEBTThe total amount of all outstanding Policy loans, includingboth principal and accrued interest.

POLICY VALUEThe sum of Invested Assets and Policy Debt less applicablecharges.

POLICY YEARA year that starts on the Policy Date or on a PolicyAnniversary.

PORTFOLIOA series of a Fund available for investment under the Policy,which corresponds to a particular Division of the SeparateAccount.

PREMIUM PAYMENTSAll payments you make under the Policy other than loanrepayments and transaction charges.

SEPARATE ACCOUNTNorthwestern Mutual Variable Life Account.

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Additional InformationMore information about the Separate Account is included in a Statement of Additional Information (“SAI”), which is dated thesame day as this prospectus, is incorporated by reference into this prospectus, and is available free of charge from the Company.To request a free copy of the Separate Account’s SAI, or current annual report, call the Variable Life Service Center us toll-freeat 1-866-424-2609. Under certain circumstances you or your financial representative may be able to obtain these documentsonline at www.northwesternmutual.com. Information about the Separate Account (including the SAI) can be reviewed and copiedat the Public Reference Room of the SEC in Washington, DC. Information on the operation of the Public Reference Room maybe obtained by calling the SEC at 1-202-551-8090. Reports and other information about the Separate Account are available on theSEC’s Internet site at http://www.sec.gov, or they may be obtained, upon payment of a duplicating fee, by writing the PublicReference Section of the SEC, 100 F Street, NE, Washington, DC 20549-0102.

Your Northwestern Mutual Financial Representative will provide you with illustrations for your Policy free of charge upon yourrequest. The illustrations show how the Death Benefit, Invested Assets and cash surrender value for the Policy would vary basedon hypothetical investment results. Your Northwestern Mutual Financial Representative will also respond to other inquiries youmay have regarding the Policy, or you may contact the Variable Life Service Center at 1-866-424-2609.

Investment Company Act File No. 811-3989

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SUMMARY PROSPECTUSMAY 1, 2017 Growth Stock Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital. Current income is a secondary objective.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.42%

Distribution and Service (12b-1) Fees None

Other Expenses 0.02%

Total Annual Portfolio Operating Expenses 0.44%

Fee Waiver(1) (0.01)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.43%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$44 $140 $246 $554

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 65.66% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in the equity securities ofmedium and large capitalization companies. For this purpose, medium and large capitalization companies are those with a marketcapitalization of companies in the Russell 1000® Growth Index. As of December 31, 2016, companies in the Russell 1000®

Growth Index had market capitalizations between approximately $644 million and $618 billion.

The Portfolio invests in stocks selected by a team of Global Research analysts, with each analyst responsible for investments in his orher area of expertise. These analysts use a fundamental research process to identify investments for the Portfolio. The analysts, under

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Growth Stock Portfolio

the direction of the director of the Global Research team, determine the Portfolio’s allocations among market sectors. The Portfolioinvests in those companies in which the analysts have the highest degree of conviction or have identified the potential for strongearnings growth or share price appreciation in the near-term. The analysts’ focus on fundamental stock selection leads them not onlyto stocks with capital-appreciation potential, but also to companies that can generate cash flow and thus support dividends.

The Portfolio seeks to reduce overall risk by diversifying its assets across economic sectors, industry groups and companies. ThePortfolio is structured so that its sector weights are generally similar to those of the Russell 1000® Growth Index, the Portfolio’sbenchmark. As a result, the Portfolio may at times have a relatively high percentage of its assets invested in a particular sector.

The Portfolio invests primarily in common stocks. It may also invest up to 20% of net assets in foreign based companies listed onforeign exchanges, either directly or through American Depositary Receipts (ADRs).

The Portfolio typically sells a security when the research analyst responsible for the investment believes there has been a changein the fundamental factors surrounding the company, the company has been fully valued, or a more attractive opportunity hasbeen identified.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objectives. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S. securities.

• Investment Style Risk – A Portfolio managed using a growth style of investing, such as the Portfolio, may underperformwhen the market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out offavor, depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mid Cap Company Risk – Investing in mid cap stocks may cause greater risk of loss and price fluctuation than investing instocks of larger cap companies due to a more limited track record, narrower product markets, more limited resources and lessliquid trading markets. These stocks may be more volatile and more difficult to buy and sell than stocks with larger capitalizations.

• Sector Concentration Risk – To the extent the Portfolio invests a relatively high percentage of its assets in a particular sector,it will have greater exposure to the risks associated with that sector, including the risk that the securities of companies withinthe sector will underperform due to adverse economic conditions, regulatory or legislative changes or increased competitionaffecting the sector. To the extent the Portfolio is underweight other sectors, the Portfolio risks missing out on advances inthose sectors.

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Growth Stock Portfolio

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2016

2007

2008

2015

2014

2013

2009

2010

2011

2012

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

50%

40%

-38.86%

9.20%

37.17%

12.37%

-1.30%

12.94%

35.86%

9.02% 6.01% 2.47%

Best Qtr: 1st – ‘12 17.23% Worst Qtr: 4th – ‘08 -22.25%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Growth Stock Portfolio2.47% 12.69% 6.32%

Russell 1000® Growth Index(reflects no deduction for fees, expenses or taxes)7.08% 14.50% 8.33%

Lipper® Variable Insurance Products (VIP) Large Cap GrowthFunds Average

(reflects deductions for fees and expenses)2.23% 13.30% 7.16%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Sub-Adviser: The Boston Company Asset Management, LLC (TBC)Portfolio Manager: Elizabeth Slover, Portfolio Manager, Senior Managing Director at TBC and Director of TBC’s GlobalResearch team, who has been with TBC since 2005, has managed the Portfolio since 2013.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–3 Northwestern Mutual Series Fund, Inc.

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SUMMARY PROSPECTUSMAY 1, 2017 Focused Appreciation Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.74%

Distribution and Service (12b-1) Fees None

Other Expenses 0.02%

Total Annual Portfolio Operating Expenses 0.76%

Fee Waiver(1) (0.13)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.63%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$64 $230 $410 $930

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 9.38% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio invests primarily in the equity securities of companies selected for their growth potential. The Portfolio focuses onequity securities of large capitalization companies, but may invest in companies of any size. For this purpose, large capitalizationcompanies are those with a market capitalization in excess of $5 billion at the time of purchase.

The adviser employs a growth style of equity management that emphasizes companies with sustainable competitive advantages,long-term structural growth drivers, profitable cash flow returns, and management teams focused on creating long-term value forshareholders. Long-term structural growth drivers are dynamics that in the manager’s opinion are not likely to change for five years

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Focused Appreciation Portfolio

or longer such as the transition of consumer shopping from in-store to online. The adviser aims to invest in companies when theytrade at a significant discount to the estimate of their intrinsic value. The intrinsic value of a company is the true worth of its businessas perceived by the portfolio managers, which may not be fully reflected in the market price of its stock. The adviser calculates theintrinsic value of a company by the discounted net present value of future cash flows. The Portfolio normally invests across a widerange of sectors and industries. The Portfolio’s sector exposure relative to its benchmark is driven by the adviser’s stock selectionprocess and, as a result, may at times have a relatively high percentage of its assets invested in a particular sector.

The Portfolio invests primarily in a core group of 30-40 securities, but may exceed this range. The Portfolio invests primarily incommon stocks. The Portfolio may invest up to 20% of its net assets in foreign securities, including American Depositary Receipts(ADRs) and emerging market securities. The Portfolio is classified as “non-diversified” under the Investment Company Act of 1940, asamended, which means it may hold a larger position in a particular company or smaller number of companies than a “diversified” fund.

The Portfolio may sell an investment when the portfolio manager believes an unfavorable structural change occurs within a givenbusiness or the markets in which it operates, a critical underlying investment assumption is flawed, when a more attractivereward-to-risk opportunity becomes available, when the current price reflects intrinsic value, or for other investment reasonswhich the portfolio manager deems appropriate.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S.securities. The Portfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political,business and social frameworks to support securities markets.

• Investment Style Risk – A Portfolio managed using a growth style of investing, such as the Portfolio, may underperformwhen the market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out offavor, depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Liquidity Risk – Certain of the Portfolio’s investments, such as small cap stocks and foreign securities, in particular emergingmarket securities, may be difficult to purchase or sell at an advantageous time or price, if at all. These risks may be magnifiedduring periods of economic turmoil or in an extended economic downturn.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mid and Small Cap Company Risk – Investing in mid and small cap stocks may cause greater risk of loss and pricefluctuation than investing in stocks of larger cap companies due to a more limited track record, narrower product markets, morelimited resources and less liquid trading markets. These stocks may be more volatile and more difficult to buy and sell thanstocks with larger capitalizations.

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Focused Appreciation Portfolio

• Non-Diversification Risk – The Portfolio is classified as a non-diversified fund and is permitted to invest a greater portion ofits assets in a single security or a small number of securities. As a result, an increase or decrease in the value of single securityheld by the Portfolio may have a greater impact on the Portfolio’s net asset value and total return, and the Portfolio’sperformance could be more volatile than the performance of funds that hold a greater number of securities.

• Sector Concentration Risk – To the extent the Portfolio invests a relatively high percentage of its assets in a particular sector,it will have greater exposure to the risks associated with that sector, including the risk that the securities of companies withinthe sector will underperform due to adverse economic conditions, regulatory or legislative changes or increased competitionaffecting the sector. To the extent the Portfolio is underweight other sectors, the Portfolio risks missing out on advances inthose sectors.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2016

2007

2008

2013

2015

2014

2009

2010

2011

2012

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

50%

40%26.84%

-40.10%

42.47%

9.33%

-6.10%

20.14%29.01%

9.43%13.64%

5.87%

Best Qtr: 2nd – ‘09 17.90% Worst Qtr: 4th – ‘08 -23.19%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Focused Appreciation Portfolio5.87% 15.33% 8.55%

Russell 1000® Growth Index(reflects no deduction for fees, expenses or taxes)7.08% 14.50% 8.33%

Lipper® Variable Insurance Products (VIP) Large Cap GrowthFunds Average

(reflects deductions for fees and expenses)2.23% 13.30% 7.16%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Loomis, Sayles & Company, L.P. (Loomis Sayles)Portfolio Manager: Aziz V. Hamzaogullari, CFA, Vice President of Loomis Sayles, joined Loomis Sayles in 2010 and beganmanaging the Portfolio in 2015.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–6

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SUMMARY PROSPECTUSMAY 1, 2017 Large Cap Core Stock Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital and income.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.43%

Distribution and Service (12b-1) Fees None

Other Expenses 0.02%

Total Annual Portfolio Operating Expenses 0.45%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$46 $144 $252 $567

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 6.83% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in equity securities oflarge capitalization companies. For this purpose, large capitalization equity investments are those whose market capitalizationsare above $5 billion at the time of purchase.

In choosing securities, the Portfolio’s portfolio managers first identify economic sectors they believe can support longer termprofit growth. Using fundamental analysis, the Portfolio’s portfolio managers then seek companies within these sectors that havedominant positions and sustainable competitive advantages in their industries, superior management that productively reinvestscash flow, sustainable profitability, strong balance sheets, expanding global presence and the potential to achieve predictable,above-average earnings and dividend growth over the next three to five years or longer. The Portfolio may also invest incompanies which the portfolio managers consider undervalued in terms of earnings, assets or growth prospects.

The Portfolio may be broadly diversified, potentially reflecting all sectors of the S&P 500® Index. However, the sectors actuallyrepresented in the Portfolio and the sector weights may differ based on the adviser’s fundamental analysis and economic outlook.As a result, the Portfolio may at times have a relatively high percentage of its assets invested in a particular sector.

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Large Cap Core Stock Portfolio

The Portfolio invests primarily in common stocks of U.S. and foreign based companies listed on U.S. exchanges. Up to 20% ofthe Portfolio’s net assets may be invested in foreign based companies listed on foreign exchanges, either directly or throughAmerican Depositary Receipts (ADRs). The Portfolio may invest in both dividend paying and non-dividend paying stocks.

The Portfolio employs a “buy-and-hold” strategy, which is an investment strategy characterized by a low portfolio turnover rate,which helps reduce the Portfolio’s trading cost. The Portfolio typically sells a security when the Portfolio’s portfolio managersbelieve there is a significant adverse change in the company’s business fundamentals that may lead to a sustained impairment inearnings power, the company has become significantly overvalued in terms of earnings, assets or growth prospects, or moreattractive alternatives exist.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in value ormore losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S. securities.

• Investment Style Risk – A portfolio managed using a particular style of investing, such as growth or value or a combination ofboth, may underperform when the market does not favor the particular style used by the Portfolio. Different investment stylestend to shift in and out of favor, depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Sector Concentration Risk – To the extent the Portfolio invests a relatively high percentage of its assets in a particular sector,it will have greater exposure to the risks associated with that sector, including the risk that the securities of companies withinthe sector will underperform due to adverse economic conditions, regulatory or legislative changes or increased competitionaffecting the sector. To the extent the Portfolio is underweight other sectors, the Portfolio risks missing out on advances inthose sectors.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the average

Northwestern Mutual Series Fund, Inc. NMSF–8

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Large Cap Core Stock Portfolio

returns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

2016

2007

2008

2013

2009

2010

2011

2012

2015

2014

9.12%

-38.74%

29.33%

12.91%

-1.21% -3.06%

11.63%

28.58%

8.56% 7.57%

Best Qtr: 2nd – ‘09 16.96% Worst Qtr: 4th – ‘08 -22.18%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Large Cap Core Stock Portfolio7.57% 10.20% 4.59%

S&P 500® Index(reflects no deduction for fees, expenses or taxes)11.96% 14.66% 6.95%

Lipper® Variable Insurance Products (VIP) Large Cap CoreFunds Average

(reflects deductions for fees and expenses)9.96% 13.28% 6.02%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Sub-Adviser: Fayez Sarofim & Co. (Sarofim & Co.)Portfolio Managers: Since 2013, the Portfolio is managed by a team of portfolio managers employed by Sarofim & Co. Theteam is supported by Sarofim & Co.’s Investment Committee, all the members of which are senior investment professionals atSarofim & Co. The team consists of:Fayez Sarofim, Chairman of the Board and Co-Chief Investment Officer, who founded Sarofim & Co. in 1958.Gentry Lee, CFA, Chief Executive Officer and Co-Chief Investment Officer of Sarofim & Co., who has been with Sarofim & Co.since 1998.Alan R. Christensen, CFA, President of Sarofim & Co., who has been with Sarofim & Co. since 2005.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–9 Northwestern Mutual Series Fund, Inc.

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SUMMARY PROSPECTUSMAY 1, 2017 Large Cap Blend Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe Portfolio’s investment objective is to seek long-term growth of capital and income.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.77%

Distribution and Service (12b-1) Fees None

Other Expenses 0.05%

Total Annual Portfolio Operating Expenses 0.82%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$84 $262 $455 $1,014

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 21.12% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of its net assets (plus any borrowings for investment purposes), in equity securities oflarge capitalization companies listed or traded on U.S. securities exchanges. The Portfolio defines large capitalization companies asthose with a market capitalization in excess of $5 billion, at the time of investment. In selecting investments, greater considerationis given to potential appreciation and future dividends than to current income. The Portfolio may hold American DepositaryReceipts (ADRs) and other equity securities of foreign issuers which are denominated in U.S. dollars. The Portfolio employs afocused investment strategy, typically investing in a core group of 20-30 large capitalization common stocks and ADRs.

The Portfolio uses fundamental analysis to look for stocks of good businesses that are selling at value prices. The Portfolio believesgood businesses have some or all of the following characteristics: a strong, defendable market or products and services niche; a highdegree of recurring revenue; modestly priced products or services; attractive return-on-investment and above average growth orimproving profitability prospects. The Portfolio considers valuation on both an absolute and relative basis utilizing both historicaland prospective analysis. In reviewing companies, the Portfolio applies the characteristics identified above on a case-by-case basis.

The adviser will generally sell a security held by the Portfolio when it believes the security has achieved its value potential, whensuch sale is necessary for diversification of the Portfolio, when changing fundamentals signal a deteriorating value potential orwhen other securities have a better value potential.

Northwestern Mutual Series Fund, Inc. NMSF–10

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Large Cap Blend Portfolio

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Focus Risk – The Portfolio’s performance could be more closely tied to the value of a single security or small number ofsecurities because, although classified as a diversified investment company, the Portfolio may hold large positions in a singleor small number of securities. As a result, the Portfolio’s performance could be more volatile than the performance of fundsthat hold a greater number of securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in value ormore losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S. securities.

• Investment Style Risk – A portfolio managed using a particular style of investing, such as growth or value or a combination ofboth, may underperform when the market does not favor the particular style used by the Portfolio. Different investment stylestend to shift in and out of favor, depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

NMSF–11 Northwestern Mutual Series Fund, Inc.

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Large Cap Blend Portfolio

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2012

2008

2009

2010

2011

2013

2014

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

-40.25%

27.40%

14.29%

-2.29%

15.20%

30.86%

12.58% 13.99%

2015

2016

-2.42%

Best Qtr: 2nd – ‘09 15.09% Worst Qtr: 4th – ‘08 -22.37%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Large Cap Blend Portfolio13.99% 13.55% 4.28%

S&P 500® Index(reflects no deduction for fees, expenses or taxes)11.96% 14.66% 6.63%

Lipper® Variable Insurance Products (VIP) Large Cap CoreFunds Average

(reflects deductions for fees and expenses)9.96% 13.28% —

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Fiduciary Management, Inc. (FMI)Portfolio Managers: FMI’s investment decisions are made by a Portfolio Management Committee (PMC). The investmentprocess employed by the PMC is team based, and the PMC as a whole, not any individual member, is primarily responsible forthe day-to-day management of the Portfolio. The PMC has managed the Portfolio since 2012. PMC members include:Patrick J. English, CFA, Chief Executive Officer and Chief Investment Officer, who has been with FMI since 1986.John S. Brandser, President, Chief Operating Officer and Chief Compliance Officer, who has been with FMI since 1995.Andy P. Ramer, CFA, Director of Research, who has been with FMI since 2002.Jonathan T. Bloom, CFA, Research Analyst, who has been with FMI since 2010.Matthew J. Goetzinger, CFA, Research Analyst, who has been with FMI since 2004.Robert M. Helf, CFA, Research Analyst, who has been with FMI since 1998.Daniel G. Sievers, CFA, Research Analyst, who has been with FMI since 2009.Matthew T. Sullivan, Research Analyst, who has been with FMI since 2013.Jordan S. Teschendorf, Research Analyst, who has been with FMI since 2015.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–12

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SUMMARY PROSPECTUSMAY 1, 2017 Index 500 Stock Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is to achieve investment results that approximate the performance of the Standard &Poor’s 500 Composite Stock Price Index (“S&P 500® Index”).

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.20%

Distribution and Service (12b-1) Fees None

Other Expenses 0.01%

Total Annual Portfolio Operating Expenses 0.21%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$22 $68 $118 $268

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 3.28% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio employs a “passive management,” or indexing, investment approach designed to track the performance of the S&P500® Index. The S&P 500® Index is composed of the stocks of primarily large capitalization companies that represent a broadspectrum of the U.S. economy and a substantial part of the U.S. stock market’s total capitalization. As of December 31, 2016, themarket capitalization range of the S&P 500® Index was approximately $3 billion to $618 billion. The Portfolio attempts toachieve its objective by investing all, or substantially all, of its assets in the stocks that make up the S&P 500® Index, holdingeach stock in approximately the same proportion as its weighting in the Index. This is known as a full replication strategy. ThePortfolio may also invest in S&P 500® Index stock futures and, to a lesser extent, purchase (long) total return equity swapagreements to help achieve full replication.

Standard & Poor’s constructs the Index by first identifying major industry categories and then allocating a representative sampleof the larger and more liquid stocks in those industries to the index. S&P weights each stock according to its float-adjustedmarket value. For example, the 50 largest companies in the index may account for over 50% of its value.

NMSF–13 Northwestern Mutual Series Fund, Inc.

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Index 500 Stock Portfolio

Because the Portfolio is managed with a goal of fully replicating the underlying S&P 500® Index, the approach employed by thePortfolio with respect to reconstitution and rebalancing aligns with the process followed generally by the S&P 500® Index.Changes to the underlying company constituents of the S&P 500® Index are made on an as-needed basis and are usuallyannounced several days before they are scheduled to be implemented. The S&P 500® Index typically makes weightingsadjustments based on changes in the amount of a constituent company’s shares outstanding on a quarterly basis. The constituentand share-based weightings changes made by S&P 500® Index will be made in a parallel fashion by the Portfolio on substantiallythe same timeline. Additionally, the Portfolio utilizes cash equitization instruments, and rebalancing occurs as necessary tomaintain balances within established target ranges for these instruments.

The Index 500 Stock Portfolio’s ability to match the performance of the S&P 500® Index will be affected to some extent by thesize and timing of cash flows into and out of the Index 500 Stock Portfolio. The Portfolio will be managed with a view toreducing such effects.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that changes in the value of thederivatives may not correlate as intended with the underlying asset, rate or index and the risk of adverse price movements inthe market. Certain derivatives involve leverage, which could cause the Portfolio to lose more than the principal amountinvested. Other risks include counterparty and liquidity risks.

• Equity Securities Risk – The value of equity securities, such as the stocks in which the Portfolio invests, could decline if thefinancial condition of the companies the Portfolio is invested in declines or if overall market and economic conditionsdeteriorate. Equity securities generally have greater price volatility than fixed income securities.

• Index Concentration Risk – Since the Portfolio implements a full replication strategy with respect to the index which ittracks, to the extent the index may be concentrated in the securities of issuers in a particular market, industry, group ofindustries, sector or asset class, the Portfolio may be similarly concentrated. As a result, Portfolio performance may beadversely affected by such concentration, the Portfolio may be subject to increased price volatility, and the Portfolio may bemore susceptible to adverse economic, market, political or regulatory developments affecting that market, industry, group ofindustries, sector or asset class in which the concentration occurs.

• Indexing Strategy Risk – A Portfolio may not perform as well as the index it attempts to match due to the Portfolio’sexpenses, changes in securities markets, changes in the composition of the underlying index and the timing of purchases andredemptions of Portfolio shares. A Portfolio using a passive management strategy is not “actively” managed, and thereforedoes not engage in shifting portfolio assets to take advantage of market opportunity, and does not attempt to manage marketvolatility, use defensive strategies or reduce the effects of any long-term periods of poor stock performance. In addition,changes in the value of a derivative used to replicate an index may not correlate as intended with the underlying index.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

Northwestern Mutual Series Fund, Inc. NMSF–14

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Index 500 Stock Portfolio

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

2016

2007

2008

2013

2015

2014

2009

2010

2011

2012

5.43%

-36.94%

26.40%

14.89%

1.95%

15.76%

32.05%

13.46%

1.17%

11.73%

Best Qtr: 2nd – ‘09 15.93% Worst Qtr: 4th – ‘08 -21.88%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Index 500 Stock Portfolio11.73% 14.41% 6.79%

S&P 500® Index(reflects no deduction for fees, expenses or taxes)11.96% 14.66% 6.95%

Lipper® Variable Insurance Products (VIP) S&P 500 Index ObjectiveFunds Average

(reflects deductions for fees and expenses)11.51% 14.20% 6.59%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Portfolio Managers: Daniel J. Meehan is a Director of MSA and joined MSA in 2004. He has co-managed the Portfolio since 2013.Steven A. Warren is a Director of MSA and joined The Northwestern Mutual Life Insurance Company (“Northwestern Mutual”)in 1998. He has co-managed the Portfolio since 2010.Joseph A. Travia is an Associate of MSA, joined MSA in 2002 and joined Northwestern Mutual in 1999. He has co-managed thePortfolio since 2014.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–15 Northwestern Mutual Series Fund, Inc.

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SUMMARY PROSPECTUSMAY 1, 2017 Large Company Value Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe Portfolio’s investment objective is to seek long-term capital growth. Income is a secondary objective.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or life insurance policy. The fees andexpenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuity contracts orvariable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variable lifeinsurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.70%

Distribution and Service (12b-1) Fees None

Other Expenses 0.06%

Total Annual Portfolio Operating Expenses 0.76%

Fee Waiver(1) (0.02)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.74%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$76 $241 $420 $940

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 79.86% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio invests primarily in larger companies. Accordingly, the Portfolio will normally have at least 80% of its net assets(plus any borrowings for investment purposes) in equity securities of companies comprising the Russell 1000® Index. As ofDecember 31, 2016, the market capitalization range of the Russell 1000® Index was approximately $644 million to $618 billion.

The adviser looks for stocks of companies that it believes are undervalued at the time of purchase. The adviser uses a valueinvestment strategy that looks for companies that are temporarily out of favor in the market. The adviser attempts to purchase thestocks of these undervalued companies and hold each stock until it has returned to favor in the market and the price has increasedto, or is higher than, a level the adviser believes more accurately reflects the fair value of the company.

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Large Company Value Portfolio

Companies may be undervalued due to market declines, poor economic conditions, actual or anticipated bad news regarding theissuer or its industry, or because they have been overlooked by the market. To identify these companies, the adviser looks forcompanies with earnings, cash flows and/or assets that may not be reflected accurately in the companies’ stock prices. Theadviser also may consider whether the companies’ securities have a favorable dividend-paying history and whether dividendpayments are expected to continue or increase.

While most assets will be invested in U.S. common stocks, other securities may also be purchased, including preferred stocks,warrants and securities convertible into common or preferred stocks, in keeping with the Portfolio’s objectives. When the adviserbelieves it is prudent, the Portfolio may invest a portion of its assets in foreign securities and American Depositary Receipts(ADRs) (up to 20% of net assets), including those of companies located in emerging markets, and utilize forwards and futures forcash management purposes or to hedge foreign currency exposure.

The adviser may sell stocks from the Portfolio if it believes a stock no longer meets established valuation criteria.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that the counterparty to a derivativestransaction fails to make the required payment or otherwise comply with the terms of the contract, the risk that changes in thevalue of the derivatives may not correlate as intended with the underlying asset, rate or index, the risk of adverse pricemovements in the market, and the risk of missed opportunities in other investments. Certain derivatives involve leverage,which could cause the Portfolio to lose more than the principal amount invested. Other risks include management, interest rate,and liquidity risks.

• Equity Securities Risk – The value of equity securities, such as common and preferred stocks, could decline if the financialcondition of the companies the Portfolio is invested in declines or if overall market and economic conditions deteriorate.Equity securities generally have greater price volatility than fixed income securities. Investments in warrants may be morevolatile than the underlying investments in stocks.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S.securities. The Portfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political,business and social frameworks to support securities markets.

• Investment Style Risk – A portfolio managed using a value style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

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Large Company Value Portfolio

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2008

2009

2010

2011

2012

2013

2014

-50%

-40%

-30%

-20%

-10%

10%

0%

20%

40%

30%

-37.23%

20.70%

10.95%

1.49%

16.47%

31.29%

13.03% 15.36%

2015

2016

-3.85%

Best Qtr: 3rd – ‘09 16.05% Worst Qtr: 4th – ‘08 -21.19%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Large Company Value Portfolio15.36% 13.90% 4.55%

Russell 1000® Value Index(reflects no deduction for fees, expenses or taxes)17.34% 14.80% 5.39%

Lipper® Variable Insurance Products (VIP) Large Cap ValueFunds Average

(reflects deductions for fees and expenses)15.59% 13.80% —

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: American Century Investment Management, Inc. (American Century)Portfolio Managers: Brendan Healy, CFA, Vice President and Portfolio Manager, joined American Century in 2000 and hasserved as a manager for the portfolio since 2007.Brian Woglom, CFA, Vice President and Portfolio Manager, joined American Century in 2005 and has served as a manager forthe Portfolio since 2016.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–18

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SUMMARY PROSPECTUSMAY 1, 2017 Domestic Equity Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital and income.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.53%

Distribution and Service (12b-1) Fees None

Other Expenses 0.02%

Total Annual Portfolio Operating Expenses 0.55%

Fee Waiver(1) (0.01)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.54%

(1) The Portfolio’s investment adviser has entered into a writtenagreement to waive a portion of its management fee. This feewaiver agreement may be terminated by the adviser at anytime after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$55 $175 $306 $688

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 12.24% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in equity securities ofU.S. issuers. Generally, the companies in which the Portfolio invests will have a market value of $5 billion or more. The Portfolioinvests in a core group of 30-40 securities.

The Portfolio primarily invests in common stocks of large-capitalization companies, but may also invest in mid-capitalizationcompanies, that its adviser believes have long-term capital appreciation potential. Typically, the Portfolio seeks securities theadviser believes are undervalued in relation to their intrinsic value. The intrinsic value of a company is the true worth of the

NMSF–19 Northwestern Mutual Series Fund, Inc.

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Domestic Equity Portfolio

business, which may not be fully reflected in the market price of its stock. The adviser seeks to determine a company’s intrinsicvalue as indicated by multiple factors, including the earnings and cash flow potential or the asset valuation of the respectiveissuers. On a selective basis, the adviser considers a company’s plans for future operation.

The Portfolio may sell a security if it no longer believes the security will contribute to meeting the investment objective of thePortfolio. In considering whether to sell a security, the Portfolio may evaluate, among other things, the factors listed above, thecondition of the U.S. economy, the condition of non-U.S. economies, and changes in the condition and outlook in the issuer’sindustry or sector.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Focus Risk – The Portfolio’s performance could be more closely tied to the value of a single security or small number ofsecurities because, although classified as a diversified investment company, the Portfolio may hold large positions in a singleor small number of securities. As a result, the Portfolio’s performance could be more volatile than the performance of fundsthat hold a greater number of securities.

• Investment Style Risk – A portfolio managed using a value style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mid Cap Company Risk – Investing in mid cap stocks may cause greater risk of loss and price fluctuation than investing instocks of larger cap companies due to a more limited track record, narrower product markets, more limited resources and lessliquid trading markets. These stocks may be more volatile and more difficult to buy and sell than stocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

Northwestern Mutual Series Fund, Inc. NMSF–20

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Domestic Equity Portfolio

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

2016

2013

2007

2008

2009

2010

2011

2012

2015

2014

-6.33%

-38.49%

29.52%

14.62%

0.91%

14.35%

34.03%

13.87%

-0.09%

14.98%

Best Qtr: 3rd – ‘09 17.74% Worst Qtr: 4th – ‘08 -19.72%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Domestic Equity Portfolio14.98% 14.92% 5.64%

Russell 1000® Value Index(reflects no deduction for fees, expenses or taxes)17.34% 14.80% 5.72%

Lipper® Variable Insurance Products (VIP) Large Cap ValueFunds Average

(reflects deductions for fees and expenses)15.59% 13.80% 5.54%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Delaware Investments Fund Advisers (Delaware), a series of Macquarie Investment Management Business TrustPortfolio Managers: D. Tysen Nutt, Jr., Senior Vice President, Senior Portfolio Manager and Team Leader, has been withDelaware since 2004, and has co-managed the Portfolio since 2012.Robert A. Vogel, Jr., CFA, Vice President and Senior Portfolio Manager, has been with Delaware since 2004, and has co-managedthe Portfolio since 2012.Nikhil G. Lalvani, CFA, Vice President and Senior Portfolio Manager, has been with Delaware since 1997, and has co-managedthe Portfolio since 2012.Kristen E. Bartholdson, Vice President and Senior Portfolio Manager, has been with Delaware since 2006, and has co-managedthe Portfolio since 2012.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–21 Northwestern Mutual Series Fund, Inc.

Page 77: The Northwestern Mutual Life Insurance Company VariableLife

SUMMARY PROSPECTUSMAY 1, 2017 Equity Income Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital and income.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.63%

Distribution and Service (12b-1) Fees None

Other Expenses 0.03%

Total Annual Portfolio Operating Expenses 0.66%

Fee Waiver(1) (0.03)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.63%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$64 $208 $365 $820

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 23.09% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in common stocks, withan emphasis on larger capitalization stocks with a strong track record of paying dividends or that are believed to be undervalued.For this purpose, larger capitalization stocks are those with a market capitalization greater than $5 billion. The Portfolio generallyseeks investments in large-capitalization companies and the Portfolio’s yield, which reflects the level of dividends paid by thePortfolio, is expected to normally exceed the yield of the S&P 500® Stock Index. This level is merely a guideline and there can beno certainty this level will be achieved.

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Equity Income Portfolio

The Portfolio will typically employ a value approach in selecting investments. The adviser’s in-house research team seeks toidentify companies that appear to be undervalued as measured by price to earnings ratio, dividend yield, enterprise value to sales,among other metrics and may be temporarily out of favor, but have good prospects for capital appreciation and dividend growth.

The adviser has the discretion to deviate from the Portfolio’s normal investment criteria, as described above, and purchasesecurities the adviser believes could provide an opportunity for substantial appreciation. These special situations might arise whenthe adviser believes a security could increase in value for a variety of reasons, including a change in management, areorganization, a spin-off of a business line, a special dividend, or some other extraordinary corporate event, a new productintroduction or a favorable competitive development.

While most assets will be invested in U.S. common stocks, other securities may also be purchased, including preferred stocks,foreign securities and American Depositary Receipts (ADRs) (up to 20% of net assets), including those of issuers located inemerging markets.

The Portfolio may sell securities for a variety of reasons such as to secure gains, limit losses, or redeploy assets into morepromising opportunities.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Dividend-Paying Stock Risk – The Portfolio’s emphasis on dividend-paying stocks could cause the Portfolio to underperformsimilar funds that invest without consideration of a company’s track record of paying dividends. Stocks with a history ofpaying dividends may not participate in a broad market advance to the same degree as most other stocks. Currently, interestrates are near unprecedented historically low levels, and a sharp rise in interest rates or economic downturn could cause acompany to unexpectedly reduce or eliminate its dividend.

• Equity Securities Risk – The value of equity securities, such as common and preferred stocks, could decline if the financialcondition of the companies the Portfolio is invested in declines or if overall market and economic conditions deteriorate.Equity securities generally have greater price volatility than fixed income securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S.securities. The Portfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political,business and social frameworks to support securities markets.

• Investment Style Risk – A portfolio managed using a value style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Special Situation Risk – In special situations, the adviser may deviate from the Portfolio’s normal investment criteria whenpurchasing a security. In these special situations, there is the risk that the change or event anticipated by the adviser when

NMSF–23 Northwestern Mutual Series Fund, Inc.

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Equity Income Portfolio

purchasing a company might not occur or attract the expected attention, which could have a negative impact on the price of theissuer’s securities. Investing in special situations may involve heightened volatility in the value of the securities purchased andmay cause greater risk of loss.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-40%

-30%

-20%

-10%

0%

10%

20%

30%

2007

2008

2009

2010

2011

2012

2014

2013

2015

2016

-35.81%

-0.92%

3.26%

24.58%

15.33% 17.23%

29.94%

7.43%

-6.74%

19.17%

Best Qtr: 2nd – ‘09 19.48% Worst Qtr: 4th – ‘08 -22.22%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Equity Income Portfolio19.17% 12.71% 5.55%

Russell 1000® Value Index(reflects no deduction for fees, expenses or taxes)17.34% 14.80% 5.72%

Lipper® Variable Insurance Products (VIP) Equity IncomeFunds Average

(reflects deductions for fees and expenses)14.21% 12.55% 5.72%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: T. Rowe Price Associates, Inc. (T. Rowe Price)Portfolio Manager: John D. Linehan, CFA, Vice President, has been with T. Rowe Price since 1998. He has managed thePortfolio since November 2015.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–24

Page 80: The Northwestern Mutual Life Insurance Company VariableLife

SUMMARY PROSPECTUSMAY 1, 2017 Mid Cap Growth Stock Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.52%

Distribution and Service (12b-1) Fees None

Other Expenses 0.02%

Total Annual Portfolio Operating Expenses 0.54%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$55 $173 $302 $677

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 57.23% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in stocks of mid-sizedcompanies. The Portfolio considers a company to be a mid cap company if it has a market capitalization no smaller than thesmallest capitalized company, and no larger than the largest capitalized company, included in the Russell Midcap® Index at thetime of investment (as of December 31, 2016, from approximately $649 million to $58 billion). Securities of companies whosemarket capitalizations no longer meet this definition after purchase may continue to be held by the Portfolio.

The Portfolio invests primarily in common stocks of mid cap domestic growth companies that are expected to experience solidgrowth in earnings. In choosing investments, the adviser evaluates the extent to which a company meets one or more of thefollowing criteria, relative to the valuation of the security: (a) the company should have or should have the expectation ofbecoming, a significant provider in the primary markets it serves, (b) the company should have some distinctive attribute relativeto present or potential competitors, (c) the prices of the company’s products or services should be based to some degree upontheir value to the customer, rather than their production cost, (d) the company should participate in an industry expected to growrapidly due to economic factors or technological change or grow through market share gains in its industry and (e) the companyshould have a strong management team.

NMSF–25 Northwestern Mutual Series Fund, Inc.

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Mid Cap Growth Stock Portfolio

The Portfolio seeks to reduce overall risk by diversifying across economic sectors, industry groups and companies. ThePortfolio’s sector exposure relative to its benchmark is driven by the adviser’s fundamental company analysis and stock selectionprocess. As a result, Portfolio may at times have a relatively high percentage of its assets invested in a particular sector.

The Portfolio may invest up to 20% of net assets in American Depositary Receipts (ADRs) and other securities of foreign issuersdenominated in U.S. dollars.

The Portfolio commonly trims positions as valuation appears incrementally less attractive, and may sell a stock when theadviser’s investment thesis is no longer valid, typically due to an erosion of company fundamentals relative to expectations orwhen valuation is no longer attractive. The Portfolio may, but is not required, to exit a position if the company’s capitalizationgrows beyond the mid cap range.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S. securities.

• Investment Style Risk – A portfolio managed using a growth style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mid Cap Company Risk – Investing in mid cap stocks may cause greater risk of loss and price fluctuation than investing instocks of larger cap companies due to a more limited track record, narrower product markets, more limited resources and lessliquid trading markets. These stocks may be more volatile and more difficult to buy and sell than stocks with larger capitalizations.

• Sector Concentration Risk – To the extent the Portfolio invests a relatively high percentage of its assets in a particular sector,it will have greater exposure to the risks associated with that sector, including the risk that the securities of companies withinthe sector will underperform due to adverse economic conditions, regulatory or legislative changes or increased competitionaffecting the sector. To the extent the Portfolio is underweight other sectors, the Portfolio risks missing out on advances inthose sectors.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

Northwestern Mutual Series Fund, Inc. NMSF–26

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Mid Cap Growth Stock Portfolio

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2016

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

2015

2014

2013

2007

2008

2009

2010

2011

2012

20.70%

-40.08%

32.09%23.86%

-6.18%

11.97%

25.53%

8.49%0.71% 0.83%

Best Qtr: 1st – ‘09 18.76% Worst Qtr: 4th – ‘08 -24.55%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Mid Cap Growth Stock Portfolio0.83% 9.14% 5.57%

Russell MidCap® Growth Index(reflects no deduction for fees, expenses or taxes)7.33% 13.51% 7.83%

Lipper® Variable Insurance Products (VIP) Mid Cap GrowthFunds Average

(reflects deductions for fees and expenses)6.61% 12.52% 7.02%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Sub-Adviser: William Blair Investment Management, LLC (William Blair)Portfolio Managers: Robert C. Lanphier IV, a Partner of William Blair, joined in 1987 and has co-managed the Portfolio since 2013.David P. Ricci, CFA, a Partner of William Blair, joined in 1994 and has co-managed the Portfolio since 2013.Daniel Crowe, CFA, a Partner of William Blair, joined in 2011 and has co-managed the Portfolio since 2015.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–27 Northwestern Mutual Series Fund, Inc.

Page 83: The Northwestern Mutual Life Insurance Company VariableLife

SUMMARY PROSPECTUSMAY 1, 2017 Index 400 Stock Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is to achieve investment results that approximate the performance of the S&P MidCap400® Stock Price Index (“S&P MidCap 400® Index”).

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.25%

Distribution and Service (12b-1) Fees None

Other Expenses 0.03%

Total Annual Portfolio Operating Expenses 0.28%

Fee Waiver(1) (0.01)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.27%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$28 $89 $156 $355

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 19.44% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio employs a “passive management,” or indexing, investment approach designed to track the performance of the S&PMidCap 400® Index. The S&P MidCap 400® Index is composed of the stocks of companies whose capitalizations generally aresmaller than those of companies that comprise the S&P 500® Index. The S&P MidCap 400® Index does not include the stocks ofthe very large companies that account for most of the weighting in the S&P 500® Index. As of December 31, 2016, the marketcapitalization range of the S&P MidCap 400® Index was approximately $1 billion to $11 billion. The Portfolio attempts toachieve its objective by investing all, or substantially all, of its assets in the stocks that make up the S&P MidCap 400® Index,

Northwestern Mutual Series Fund, Inc. NMSF–28

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Index 400 Stock Portfolio

holding each stock in approximately the same proportion as its weighting in the Index. This is known as a full replicationstrategy. The Portfolio may also invest in S&P MidCap 400® Index stock futures and, to a lesser extent, purchase (long) totalreturn equity swap agreements to help achieve full replication.

Standard & Poor’s constructs the index by first identifying major industry categories and then allocating a representative sampleof the larger and more liquid stocks in those industries to the index. S&P weights each stock according to its float-adjustedmarket value. For example, the 50 largest companies in the index may account for over 50% of its value.

Because the Portfolio is managed with a goal of fully replicating the underlying S&P MidCap 400® Index, the approachemployed by the Portfolio with respect to reconstitution and rebalancing aligns with the process followed generally by the S&PMidCap 400® Index. Changes to the underlying company constituents of the S&P MidCap 400® Index are made on an as-neededbasis and are usually announced several days before they are scheduled to be implemented. The S&P MidCap 400® Indextypically makes weightings adjustments based on changes in the amount of a constituent company’s shares outstanding on aquarterly basis. The constituent and share-based weightings changes made by S&P MidCap 400® Index will be made in a parallelfashion by the Portfolio on substantially the same timeline. Additionally, the Portfolio utilizes cash equitization instruments, andrebalancing occurs as necessary to maintain balances within established target ranges for these instruments.

The Index 400 Stock Portfolio’s ability to match the performance of the S&P MidCap 400® Index will be affected to some extentby the size and timing of cash flows into and out of the Index 400 Stock Portfolio. The Portfolio will be managed with a view toreducing such effects.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that changes in the value of thederivatives may not correlate as intended with the underlying asset, rate or index and the risk of adverse price movements inthe market. Certain derivatives involve leverage, which could cause the Portfolio to lose more than the principal amountinvested. Other risks include counterparty and liquidity risks.

• Equity Securities Risk – The value of equity securities, such as the stocks in which the Portfolio invests, could decline if thefinancial condition of the companies the Portfolio is invested in declines or if overall market and economic conditionsdeteriorate. Equity securities generally have greater price volatility than fixed income securities.

• Index Concentration Risk – Since the Portfolio implements a full replication strategy with respect to the index which ittracks, to the extent the index may be concentrated in the securities of issuers in a particular market, industry, group ofindustries, sector or asset class, the Portfolio may be similarly concentrated. As a result, Portfolio performance may beadversely affected by such concentration, the Portfolio may be subject to increased price volatility, and the Portfolio may bemore susceptible to adverse economic, market, political or regulatory developments affecting that market, industry, group ofindustries, sector or asset class in which the concentration occurs.

• Indexing Strategy Risk – A Portfolio may not perform as well as the index it attempts to match due to the Portfolio’sexpenses, changes in securities markets, changes in the composition of the underlying index and the timing of purchases andredemptions of Portfolio shares. A Portfolio using a passive management strategy is not “actively” managed, and thereforedoes not engage in shifting portfolio assets to take advantage of market opportunity, and does not attempt to manage marketvolatility, use defensive strategies or reduce the effects of any long-term periods of poor stock performance. In addition,changes in the value of a derivative used to replicate an index may not correlate as intended with the underlying index.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mid Cap Company Risk – Investing in mid cap stocks may cause greater risk of loss and price fluctuation than investing instocks of larger cap companies due to a more limited track record, narrower product markets, more limited resources and lessliquid trading markets. These stocks may be more volatile and more difficult to buy and sell than stocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

NMSF–29 Northwestern Mutual Series Fund, Inc.

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Index 400 Stock Portfolio

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-40%

-30%

-20%

-10%

0%

10%

20%

40%

30%

2016

2007

2008

2009

2010

2011

2012

2015

2014

2013

-36.28%

-1.92%

7.93%

37.00%

26.29%

17.64%

33.16%

9.42%

-2.38%

20.38%

Best Qtr: 3rd – ‘09 19.84% Worst Qtr: 4th – ‘08 -25.60%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Index 400 Stock Portfolio20.38% 15.03% 8.92%

S&P MidCap 400® Index(reflects no deduction for fees, expenses or taxes)20.74% 15.33% 9.16%

Lipper® Variable Insurance Products (VIP) Mid Cap CoreFunds Average

(reflects deductions for fees and expenses)16.86% 13.97% 7.43%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Portfolio Managers: Daniel J. Meehan is a Director of MSA and joined MSA in 2004. He has co-managed the Portfolio since 2013.Steven A. Warren is a Director of MSA and joined The Northwestern Mutual Life Insurance Company (“Northwestern Mutual”)in 1998. He has co-managed the Portfolio since 2010.Joseph A. Travia is an Associate of MSA, joined MSA in 2002 and joined Northwestern Mutual in 1999. He has co-managed thePortfolio since 2014.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–30

Page 86: The Northwestern Mutual Life Insurance Company VariableLife

SUMMARY PROSPECTUSMAY 1, 2017 Mid Cap Value Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term capital growth. Current income is a secondary objective.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.85%

Distribution and Service (12b-1) Fees None

Other Expenses 0.05%

Total Annual Portfolio Operating Expenses 0.90%

Fee Waiver(1) (0.12)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.78%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$80 $275 $487 $1,097

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 53.81% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in equity securities ofmid-sized companies. The Portfolio invests primarily in a diversified portfolio of equity securities of mid-sized companies thatare determined by Portfolio’s adviser to be undervalued at the time of purchase. At the time of investment, companies purchasedtypically will fall within the capitalization range of the Russell 3000® Index, excluding the largest 100 such companies,(approximately $21 million to $50 billion as of December 31, 2016). The adviser intends to manage the Portfolio so that itsweighted capitalization falls within the capitalization range of the members of the Russell MidCap® Index (approximately $644million to $58 billion as of December 31, 2016).

NMSF–31 Northwestern Mutual Series Fund, Inc.

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Mid Cap Value Portfolio

In managing the Portfolio, the adviser uses its own fundamental value approach. In selecting securities for the Portfolio, theadviser attempts to identify companies whose long-term earnings, cash flows and/or assets are not reflected in the current marketprice of their securities and hold each security until it has returned to favor in the market and the price has increased to, or ishigher than a level the adviser believes more accurately reflects the fair value of the company. The adviser may also considerwhether the companies’ securities have a favorable dividend-paying history and whether dividend payments are expected tocontinue or increase. The adviser may also use this fundamental value approach to invest the Portfolio in initial public offerings(IPOs) from time to time when such opportunities are attractive and consistent with the Portfolio’s investment objectives.

While most assets will be invested in U.S. common stocks, other securities may also be purchased, including preferred stocks,warrants and securities convertible into common or preferred stocks, in keeping with the Portfolio’s objectives. The Portfolio mayinvest in American Depositary Receipts (ADRs) and foreign securities (up to 20% of net assets), including those of companies locatedin emerging markets, and may utilize forwards and futures for cash management purposes or to hedge foreign currency exposure.

The adviser may sell a stock from the Portfolio if it believes the stock no longer meets established valuation criteria, the stock’srisk parameters outweigh its return opportunity, specific events alter a stock’s prospects or more attractive opportunities areidentified. In seeking to achieve its investment objective, the adviser may sell shares from the Portfolio without regard to thelength of time a security has been held.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that the counterparty to a derivativestransaction fails to make the required payment or otherwise comply with the terms of the contract, the risk that changes in thevalue of the derivatives may not correlate as intended with the underlying asset, rate or index, and the risk of missedopportunities in other investments. Certain derivatives involve leverage, which could cause the Portfolio to lose more than theprincipal amount invested. Other risks include management, market, interest rate, and liquidity risks.

• Equity Securities Risk – The value of equity securities, such as common and preferred stocks, could decline if the financialcondition of the companies the Portfolio is invested in declines or if overall market and economic conditions deteriorate.Equity securities generally have greater price volatility than fixed income securities. Investments in warrants may be morevolatile than the underlying investments in stocks.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S.securities. The Portfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political,business and social frameworks to support securities markets.

• Investment Style Risk – A portfolio managed using a value style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

• IPO Risk – The value of securities acquired in an IPO may rise or fall more rapidly than other investments due to factors suchas the absence of an established public market, unseasoned trading and speculation, a potentially small number of securitiesavailable for trading, limited information about the issuer and other factors. The purchase of securities in an IPO may involvehigher transaction costs than those associated with the purchase of securities with an established market.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

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Mid Cap Value Portfolio

• Mid Cap Company Risk – Investing in mid cap stocks may cause greater risk of loss and price fluctuation than investing instocks of larger cap companies due to a more limited track record, narrower product markets, more limited resources and lessliquid trading markets. These stocks may be more volatile and more difficult to buy and sell than stocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-50%

-40%

-30%

-20%

-10%

10%

20%

30%

40%

0%

2016

2007

2008

2009

2010

2011

2012

2013

2015

2014

-0.16%

-35.07%

23.24%19.93%

-0.61%

16.57%

30.24%

16.69%

-1.33%

23.23%

Best Qtr: 3rd – ‘09 17.60% Worst Qtr: 4th – ‘08 -27.36%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Mid Cap Value Portfolio23.23% 16.59% 7.45%

Russell MidCap® Value Index(reflects no deduction for fees, expenses or taxes)20.00% 15.70% 7.59%

Lipper® Variable Insurance Products (VIP) Mid Cap ValueFunds Average

(reflects deductions for fees and expenses)19.06% 14.49% 6.39%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: American Century Investment Management, Inc. (American Century)Portfolio Managers: Phillip N. Davidson, CFA, Chief Investment Officer Value – Equity, Senior Vice President and SeniorPortfolio Manager joined American Century in 1993 as a Portfolio Manager, and began managing the Portfolio in 2009.Michael Liss, CFA, CPA, Vice President and Senior Portfolio Manager, has served American Century as a Portfolio Managersince 2004 and began managing the Portfolio in 2009.Kevin Toney, CFA, Senior Vice President and Senior Portfolio Manager, has served American Century as a Portfolio Managersince 2006 and began managing the Portfolio in 2009.Brian Woglom, CFA, Vice President and Portfolio Manager, has served American Century as a Portfolio Manager since 2012 andbegan managing the Portfolio in 2012.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

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SUMMARY PROSPECTUSMAY 1, 2017 Small Cap Growth Stock Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.55%

Distribution and Service (12b-1) Fees None

Other Expenses 0.04%

Total Annual Portfolio Operating Expenses 0.59%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$60 $189 $329 $738

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 44.26% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in common stocks ofsmall capitalization companies. The Portfolio defines small capitalization companies as companies with market capitalizationswithin the collective range of the Russell 2000® and S&P SmallCap 600® Indices. As of December 31, 2016, this range wasapproximately $21 million to $11 billion. Some of the companies in which the Portfolio invests may be considered micro capcompanies (defined as companies with stock market capitalizations less than $500 million at the time of investment).

The Portfolio’s investment process is derived from the observation that the quality and persistence of a company’s business isoften not reflected in its current stock price. Central to the investment process is intense, fundamental research focused onuncovering companies with improving quality metrics, business momentum, and attractive relative valuations. The investmentprocess is aided by a proprietary screening process that narrows the investment universe to companies that are consistent with theinvestment philosophy. The investment team conducts fundamental research on companies elevated by the screening process.Research emphasizes the sustainability of a business’s competitive advantages and the ability to generate revenue and increaseprofit margins. Other important considerations include capital allocation discipline, and other qualitative factors such as strengthof company management, and analysis of products and competition. Valuation analysis is an important component of theinvestment process and consists of both cash flow and earnings ratios that are compared with the industry average.

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Small Cap Growth Stock Portfolio

Portfolio construction emphasizes stock specific risk while minimizing other sources of active risk. The Portfolio is structured sothat its sector weights are generally similar to those of the Russell 2000® Growth Index, the Portfolio’s benchmark. As a result,the Portfolio may at times have a relatively high percentage of its assets invested in a particular sector and may hold securitieswhich are not represented in the benchmark. However, in constructing the Portfolio, the investment team monitors differentsources of active risk including stock-specific risk, industry risk and style risk. The goal of this analysis is to ensure that thePortfolio remains well diversified and does not have unrewarded or unintended industry and style exposure as a consequence ofindividual stock selections.

The Portfolio invests primarily in U.S. common stocks. The Portfolio may also invest up to 20% of net assets in AmericanDepositary Receipts (ADRs) and other equity securities of foreign issuers, including those located in emerging markets, whichare denominated in U.S. dollars.

The Portfolio may also utilize exchange-traded funds as part of its cash management strategy.

The Portfolio may sell a security for a variety of reasons including when it no longer demonstrates improving quality or exhibitsstrong fundamental momentum, when fundamentals have changed, where the risk/reward assessment is no longer favorable, or toredeploy assets into more promising opportunities. The Portfolio may, but is not required, to exit a position if the company’scapitalization grows beyond the small cap range.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money. The value of securities identified using quantitativeanalysis can react differently to issuer, political, market and economic developments from the market as a whole or securitiesidentified using only fundamental analysis. The factors used in quantitative analysis and the weight placed on those factorsmay not be predictive of a security’s value.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Exchange Traded Funds Risk – Investing in exchange traded funds (ETFs) may expose the Portfolio to greater risk of lossand price fluctuation than investing directly in a comparable portfolio of stocks comprising the index due to lack of liquidity,the additional expense incurred as a shareholder in another investment company, and tracking error. ETFs are also subject tothe risk that their market prices may trade at a premium or discount to their net asset value, which means the Portfolio willoverpay for an ETF’s assets if it is trading at a premium and will get less than the value of the ETF’s assets when selling if it istrading at a discount. An active market for an ETF may not be developed or maintained. Trading of an ETF’s shares may behalted by the exchange, in which case the Portfolio would be unable to sell its ETF shares unless and until trading is resumed.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S.securities. The Portfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political,business and social frameworks to support securities markets.

• Investment Style Risk – A portfolio managed using a growth style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

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Small Cap Growth Stock Portfolio

• Liquidity Risk – Markets for small and micro cap stocks and foreign securities, in particular emerging markets securities, maybe less liquid than markets for larger cap stocks and domestic securities, and therefore may be difficult to purchase or sell at anadvantageous time or price, if at all. These risks may be magnified during periods of economic turmoil or in an extendedeconomic downturn.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Micro Cap Company Risk – Investing in micro cap stocks may cause the Portfolio to experience more rapid and extremechanges in value than a fund that invests solely in small, mid and large cap stocks due to a more limited track record, narrowerproduct markets, more limited resources, higher risk of failure, and less liquid trading markets.

• Sector Concentration Risk – To the extent the Portfolio invests a relatively high percentage of its assets in a particular sector,it will have greater exposure to the risks associated with that sector, including the risk that the securities of companies withinthe sector will underperform due to adverse economic conditions, regulatory or legislative changes or increased competitionaffecting the sector. To the extent the Portfolio is underweight other sectors, the Portfolio risks missing out on advances inthose sectors.

• Small Cap Company Risk – Investing in small cap stocks may cause greater risk of loss and price fluctuation than investing instocks of larger cap companies due to a more limited track record, narrower product markets, more limited resources and lessliquid trading markets. These stocks may be more volatile and more difficult to buy and sell than stocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2007

2008

2009

2010

2011

2014

2013

2012

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

50%

40%

9.54%

-43.87%

31.17%25.85%

-2.78%

9.48%

38.60%

8.66%

2016

2015

12.25%

0.32%

Best Qtr: 4th – ‘10 17.08% Worst Qtr: 4th – ‘08 -26.31%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Small Cap Growth Stock Portfolio12.25% 13.17% 6.24%

Russell 2000® Growth Index(reflects no deduction for fees, expenses or taxes)11.32% 13.74% 7.76%

Lipper® Variable Insurance Products (VIP) Small Cap GrowthFunds Average

(reflects deductions for fees and expenses)9.97% 12.46% 7.29%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Sub-Adviser: Wellington Management Company LLP (Wellington Management)Portfolio Manager: Mammen Chally, CFA, Senior Managing Director and Equity Portfolio Manager, joined WellingtonManagement in 1994 and has managed the Portfolio since 2013.

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Small Cap Growth Stock Portfolio

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–37 Northwestern Mutual Series Fund, Inc.

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SUMMARY PROSPECTUSMAY 1, 2017 Index 600 Stock Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe Portfolio’s investment objective is to achieve investment results that approximate the performance of the Standard & Poor’sSmallCap 600® Index (“S&P SmallCap 600® Index”).

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.25%

Distribution and Service (12b-1) Fees None

Other Expenses 0.11%

Total Annual Portfolio Operating Expenses 0.36%

Expense Reimbursement(1) (0.01)%

Total Annual Portfolio Operating Expenses AfterExpense Reimbursement(1) 0.35%

(1) The Portfolio’s investment adviser has entered into awritten expense limitation agreement under which it hasagreed to limit the total expenses of the Portfolio (excludingtaxes, brokerage, other investment-related costs, interest anddividend expenses and charges, acquired fund fees andexpenses and such non-recurring and extra ordinary expensesas they may arise) to an annual rate of 0.35% of the Portfolio’saverage net assets. This expense limitation agreement may beterminated by the adviser at any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the expense reimbursementagreement with the investment adviser for the first year only.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$36 $115 $201 $455

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 52.14% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio employs a “passive management,” or indexing, investment approach designed to track the performance of the S&PSmallCap 600® Index. S&P SmallCap 600® Index is composed of 600 domestic stocks with market capitalizations rangingbetween approximately $52 million and $15 billion as of December 31, 2016. The Portfolio attempts to achieve its objective byinvesting all, or substantially all, of its assets in stock that make up the S&P SmallCap 600® Index, holding each stock in

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Index 600 Stock Portfolio

approximately the same proportion as its weighting in the Index. This is known as a full replication strategy. The Portfolio mayalso purchase (long) total return equity swap agreements and invest in exchange traded funds and, to a lesser extent, futurescontracts, for cash management purposes and to help achieve full replication.

Standard & Poor’s constructs the index by first identifying major industry categories and then allocating a representative sampleof the larger and more liquid stocks in those industries to the index. S&P weights each stock according to its float-adjustedmarket value. For example, the 50 largest companies in the index may account for over 50% of its value.

Because the Portfolio is managed with a goal of fully replicating the underlying S&P SmallCap 600® Index, the approachemployed by the Portfolio with respect to reconstitution and rebalancing aligns with the process followed generally by theS&P SmallCap 600® Index. Changes to the underlying company constituents of the S&P SmallCap 600® Index are made on anas-needed basis and are usually announced several days before they are scheduled to be implemented. The S&P SmallCap 600®

Index typically makes weightings adjustments based on changes in the amount of a constituent company’s shares outstanding ona quarterly basis. The constituent and share-based weightings changes made by S&P SmallCap 600® Index will be made in aparallel fashion by the Portfolio on substantially the same timeline. Additionally, the Portfolio utilizes cash equitizationinstruments, and rebalancing occurs as necessary to maintain balances within established target ranges for these instruments.

The Index 600 Stock Portfolio’s ability to match the performance of the S&P SmallCap 600® Index will be affected to someextent by the size and timing of cash flows into and out of the Index 600 Stock Portfolio. The Portfolio will be managed with aview to reducing such effects.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that changes in the value of thederivatives may not correlate as intended with the underlying asset, rate or index, the risk of adverse price movements in themarket. Certain derivatives involve leverage, which could cause the Portfolio to lose more than the principal amount invested.Other risks include counterparty and liquidity risks. In particular, the Portfolio’s purchase of total return equity swapagreements may pose risk arising from losses if the underlying reference asset does not perform as anticipated; suchagreements are also subject to counterparty credit, liquidity and leveraging risks. The Portfolio’s purchase of future contractsmay involve risks related to imperfect correlation between the changes in the prices of such instruments and the price of theunderlying asset, as well as leverage, liquidity and volatility risks.

• Equity Securities Risk – The value of equity securities, such as the stocks in which the Portfolio invests, could decline if thefinancial condition of the companies the Portfolio is invested in declines or if overall market and economic conditionsdeteriorate. Equity securities generally have greater price volatility than fixed income securities.

• Exchange Traded Funds Risk – Investing in exchange traded funds (ETFs) may expose the Portfolio to greater risk of lossand price fluctuation than investing directly in a comparable portfolio of stocks comprising the index due to lack of liquidity,the additional expenses incurred as a shareholder in another investment company, and tracking error. ETFs are also subject tothe risk that their market prices may trade at a premium or discount to their net asset value, which means the Portfolio willoverpay for an ETF’s assets if it is trading at a premium and will get less than the value of the ETF’s assets when selling if it istrading at a discount. An active market for an ETF may not be developed or maintained. Trading of an ETF’s shares may behalted by the exchange, in which case the Portfolio would be unable to sell its ETF shares unless and until trading is resumed.

• Index Concentration Risk – Since the Portfolio implements a full replication strategy with respect to the index which ittracks, to the extent the index may be concentrated in the securities of issuers in a particular market, industry, group ofindustries, sector or asset class, the Portfolio may be similarly concentrated. As a result, Portfolio performance may beadversely affected by such concentration, the Portfolio may be subject to increased price volatility, and the Portfolio may bemore susceptible to adverse economic, market, political or regulatory developments affecting that market, industry, group ofindustries, sector or asset class in which the concentration occurs.

• Indexing Strategy Risk – A Portfolio may not perform as well as the index it attempts to match due to the Portfolio’sexpenses, changes in securities markets, changes in the composition of the underlying index and the timing of purchases andredemptions of Portfolio shares. A Portfolio using a passive management strategy is not “actively” managed, and thereforedoes not engage in shifting portfolio assets to take advantage of market opportunity, and does not attempt to manage marketvolatility, use defensive strategies or reduce the effects of any long-term periods of poor stock performance. In addition,changes in the value of a derivative used to replicate an index may not correlate as intended with the underlying index.

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Index 600 Stock Portfolio

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Small Cap Company Risk – Investing in small cap stocks may cause greater risk of loss and price fluctuation than investing instocks of larger cap companies due to a more limited track record, narrower product markets, more limited resources and lessliquid trading markets. These stocks may be more volatile and more difficult to buy and sell than stocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2008

2009

2010

2011

2012

2013

2014

-40%

-30%

-20%

-10%

10%

20%

30%

50%

40%

0%

-31.30%

0.90%

25.17%25.90%

15.80%

40.67%

5.34%

2015

2016

26.12%

-2.35%

Best Qtr: 2nd – ‘09 21.02% Worst Qtr: 4th – ‘08 -25.21%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Index 600 Stock Portfolio26.12% 16.14% 8.35%

S&P SmallCap 600® Index(reflects no deduction for fees, expenses or taxes)26.56% 16.62% 8.74%

Lipper® Variable Insurance Products (VIP) Small Cap CoreFunds Average

(reflects deductions for fees and expenses)21.76% 14.29% —

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Portfolio Managers: Daniel J. Meehan is a Director of MSA and joined MSA in 2004. He has co-managed the Portfolio since 2013.Steven A. Warren is a Director of MSA and joined The Northwestern Mutual Life Insurance Company (“Northwestern Mutual”)in 1998. He has co-managed the Portfolio since 2010.Joseph A. Travia is an Associate of MSA, joined MSA in 2002 and joined Northwestern Mutual in 1999. He has co-managed thePortfolio since 2014.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–40

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SUMMARY PROSPECTUSMAY 1, 2017 Small Cap Value Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.85%

Distribution and Service (12b-1) Fees None

Other Expenses 0.04%

Acquired Fund Fees and Expenses 0.14%

Total Annual Portfolio Operating Expenses(1) 1.03%

(1) Includes fees and expenses incurred indirectly by thePortfolio as a result of investments in other investmentcompanies (Acquired Fund Fees and Expenses). The operatingexpenses of the Portfolio reflected in the Portfolio’s mostrecent annual report and Financial Highlights do not includeAcquired Fund Fees and Expenses.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$105 $328 $569 $1,261

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 24.02% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets in common stocks of companies with market capitalizations that do notexceed the maximum market capitalization of any security in the Russell 2000® Index at the time of purchase (approximately $11billion as of December 31, 2016). The market capitalization of companies in the Portfolio and the Index changes over time andthe Portfolio will not sell a stock just because the company has grown to a market capitalization outside of the range. ThePortfolio may, on occasion, purchase companies with a market capitalization above the range. Securities falling outside of themarket capitalization range noted above will not be included in the overall calculation of assets but not counted as fulfilling the80% minimum. The Portfolio may also invest in the equity securities of micro cap companies (defined as companies with stockmarket capitalizations less than $500 million at the time of investment).

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Small Cap Value Portfolio

Reflecting a value approach to investing, the Portfolio will seek the stocks of companies whose current stock prices do not appearto adequately reflect their underlying value as measured by assets, earnings, cash flow or business franchises. The in-houseresearch team at the adviser generally looks for some of the following:

• low price/earnings, price/book value, or price/cash flow ratios relative to the Russell 2000® Index the company’s peers, or itsown historical norm;

• low stock price relative to a company’s underlying asset values;

• above-average dividend yield relative to a company’s peers or its own historical norm;

• a plan to improve the business through restructuring; and

• a sound balance sheet and other positive financial characteristics.

While the Portfolio does not seek to focus its investments in any particular economic sector, the Portfolio may at times have arelatively high percentage of its assets invested in a particular sector as a result of the adviser’s stock selection process.

In pursuing its investment objective, the adviser has the discretion to deviate from its normal investment criteria, as describedabove, and purchase securities the adviser believes could provide an opportunity for substantial appreciation. These specialsituations might arise when the adviser believes a security could increase in value for a variety of reasons, including a change inmanagement, a reorganization, a spin-off of a business line, a special dividend, or some other extraordinary corporate event, anew product introduction or innovation, or a favorable competitive environment.

While most assets will be invested in U.S. common stocks, other securities may also be purchased, including AmericanDepositary Receipts (ADRs) and foreign securities (up to 20% of net assets), including those of issuers located in emergingmarkets, real estate investment trust (REITs) and securities of other investment companies, including open-end funds, closed-endfunds, exchange traded funds (ETFs) and business development companies (BDCs), in keeping with the Portfolio’s objectives.

The Portfolio may sell securities for a variety of reasons, such as to secure gains, limit losses or redeploy assets into morepromising opportunities.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S.securities. The Portfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political,business and social frameworks to support securities markets.

• Investment Style Risk – A portfolio managed using a value style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

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Small Cap Value Portfolio

• Micro Cap Company Risk – Investing in micro cap stocks may cause the Portfolio to experience more rapid and extremechanges in value than a fund that invests solely in small, mid and large cap stocks due to a more limited track record, narrowerproduct markets, more limited resources, higher risk of failure, and less liquid trading markets.

• Other Investment Companies Risk – The Portfolio will indirectly bear its pro rata portion of the expenses of the investmentcompanies in which it invests, including advisory fees, in addition to the direct expenses of the Portfolio. The expensesassociated with some business development companies may be significant. Investments in other investment companies aresubject to market and selection risks, and generally entail the same risks as the underlying securities held by them. ETFs,closed-end funds and BDCs are also subject to the risk that their market prices may trade at a premium or a discount to theirnet asset value, which means the Portfolio will overpay for a fund’s assets if it is trading at a premium and will get less than thevalue of the fund’s assets when selling if it is trading at a discount. An active trading market for an ETF, closed-end fund orBDC may not be developed or maintained. In the event of a trading halt by the exchange, the Portfolio would be unable to sellits ETF, closed-end or BDC shares unless and until trading is resumed. BDCs invest in small and medium-sized privatecompanies that may not have access to public equity markets. As a result, a BDC’s portfolio may be less liquid, may be moreadversely affected by poor economic or market conditions, and may be adversely affected by risks associated with industriesand sectors in which portfolio companies may concentrate.

• REITs Risk – REITs must satisfy specific requirements for favorable tax treatment and can involve unique risks in addition tothe risks generally affecting the real estate industry. REITs are dependent upon the quality of their management, may havelimited financial resources and heavy cash flow dependency, and may not be diversified geographically or by property type.

• Sector Concentration Risk – To the extent the Portfolio invests a relatively high percentage of its assets in a particular sector,it will have greater exposure to the risks associated with that sector, including the risk that the securities of companies withinthe sector will underperform due to adverse economic conditions, regulatory or legislative changes or increased competitionaffecting the sector. To the extent the Portfolio is underweight other sectors, the Portfolio risks missing out on advances inthose sectors.

• Small Cap Company Risk – Investing in small cap stocks may cause greater risk of loss and price fluctuation than investing instocks of larger cap companies due to a more limited track record, narrower product markets, more limited resources and lessliquid trading markets. These stocks may be more volatile and more difficult to buy and sell than stocks with larger capitalizations.

• Special Situation Risk – In special situations, the adviser may deviate from the Portfolio’s normal investment criteria whenpurchasing a security. In these special situations, there is the risk that the change or event anticipated by the adviser whenpurchasing a company might not occur or attract the expected attention, which could have a negative impact on the price of thecompany’s securities. Investing in special situations may involve heightened volatility in the value of the securities purchasedand may cause greater risk of loss.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

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Small Cap Value Portfolio

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2015

2014

2013

-30%

-20%

-10%

0%

10%

20%

30%

40%

2007

2008

2009

2010

2011

2012

2016

-0.83%

-28.13%

28.18%21.95%

-1.36%-5.45%

16.33%

31.76%

0.22%

32.39%

Best Qtr: 2nd – ‘09 20.83% Worst Qtr: 4th – ‘08 -25.12%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Small Cap Value Portfolio32.39% 13.97% 7.77%

Russell 2000® Value Index(reflects no deduction for fees, expenses or taxes)31.74% 15.07% 6.26%

Lipper® Variable Insurance Products (VIP) Small Cap ValueFunds Average

(reflects deductions for fees and expenses)27.76% 14.61% 7.10%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: T. Rowe Price Associates, Inc. (T. Rowe Price)Portfolio Manager: J. David Wagner, CFA, a Vice President of T. Rowe Price, joined T. Rowe Price in 2000 and has managedthe Portfolio since 2014.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

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SUMMARY PROSPECTUSMAY 1, 2017 International Growth Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.62%

Distribution and Service (12b-1) Fees None

Other Expenses 0.09%

Total Annual Portfolio Operating Expenses 0.71%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$73 $227 $395 $883

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 25.57% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio will invest at least 80% of net assets (plus any borrowings for investment purposes) in the securities ofissuers from countries outside the United States. The Portfolio may invest in emerging markets but will normally limit suchinvestments to 20% of its net assets, measured at the time of purchase. The adviser normally invests the Portfolio’s assetsprimarily in foreign common stocks and American Depositary Receipts (ADRs) and other depositary receipts. While the advisernormally allocates the Portfolio’s assets across different countries and regions, the Portfolio may invest a relatively largepercentage of its assets in a single country, a small number of countries, or a particular geographic region. The Portfolio investsprimarily in large capitalization companies, but may invest in companies of any size. Although the Portfolio primarily invests itsassets in issuers located outside the U.S., it also invests in U.S. issuers.

The adviser invests the Portfolio’s assets in companies it believes operate in a market environment, or with a competitive advantage,that make it difficult for competition to disrupt current and future profitability, in combination with growth drivers that may offerabove-average growth potential measured by factors such as earnings or revenue. Companies with high growth potential tend to becompanies with higher than average price/earnings (P/E) or price/book (P/B) ratios. Companies with strong growth potential oftenhave new products, technologies, distribution channels, or other opportunities, or have a strong industry or market position. The

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International Growth Portfolio

stocks of these companies are often called “growth” stocks. In buying and selling securities for the Portfolio, the adviser relies onfundamental analysis, which involves a “bottom up” assessment of a company’s potential for success in light of factors such as itsfinancial condition, earnings outlook, strategy, management, industry position, and economic and market conditions.

The Portfolio may reduce or sell its position in a particular holding when the adviser believes a stock is fully valued, the conditionsupon which the adviser based its original investment thesis no longer holds true, or due to portfolio construction considerations.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Emerging Markets Risk – Investing in emerging market securities increases foreign investing risk, and may subject thePortfolio to more rapid and extreme changes in value or more losses than a fund that invests exclusively in U.S. securities or inforeign, developed countries. This risk is due to smaller markets, illiquidity, significant price and market volatility, currency,interest rate and commodity price fluctuations, restrictions on foreign investment, changes in tax policy, differing securitiesmarket structures, higher transaction costs, and various administrative difficulties, such as delays in executing, clearing andsettling portfolio transactions or in receiving payment of dividends.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Foreign Currency Risk – The risk that foreign (non-U.S. dollar) currency denominated securities, or derivatives that provideexposure to foreign currencies, may be adversely affected by decreases in foreign currency values relative to the U.S. dollar.Investments in securities subject to foreign currency risk may have more rapid and extreme changes in value or more lossesthan investments in U.S. dollar denominated securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be less liquid, more volatile, and harderto value than U.S. securities.

• Geographic Concentration Risk – To the extent a relatively large percentage of the Portfolio’s assets are invested in issuerslocated in a single country, a small number of countries, or a particular geographic region, the Portfolio’s performance could bemore volatile than that of a more geographically diversified fund, and the Portfolio’s performance may be more closely tied tothe market, currency, economic, political, or regulatory conditions in those countries or that region.

• Investment Style Risk – A portfolio managed using a growth style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Liquidity Risk – Markets for small cap stocks and foreign securities, in particular emerging markets securities, may be lessliquid than markets for larger cap stocks and domestic securities, and therefore may be difficult to purchase or sell at anadvantageous time or price, if at all. These risks may be magnified during periods of economic turmoil or in an extendedeconomic downturn.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

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• Small and Mid Cap Company Risk – Investing in small and mid cap stocks may cause greater risk of loss and pricefluctuation than investing in stocks of larger cap companies due to a more limited track record, narrower product markets, morelimited resources and less liquid trading markets. These stocks may be more volatile and more difficult to buy and sell thanstocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance, the returns of an additionalindex of securities with characteristics similar to those that the Portfolio typically holds, and the average returns of a peer groupof portfolios underlying variable insurance products with similar characteristics to those of the Portfolio. Returns are based onpast results and are not an indication of future performance. Neither the bar chart nor the table reflects the fees and expensesseparately charged by the variable annuity contract or variable life insurance policy separate account that invests in the Portfolioand returns would be lower if those fees and expenses were reflected.

2007

2008

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

50%

40%

30%

2009

2010

2011

2012

2015

2014

2013

2016

-46.19%

-13.17%

12.62%

23.16%16.43% 17.99%19.81%

-4.52%-1.73%-3.41%

Best Qtr: 2nd – ‘09 17.83% Worst Qtr: 3rd – ‘08 -22.62%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

International Growth Portfolio-3.41% 5.08% -0.34%

MSCI EAFE® (Europe-Australasia-Far East) Growth Index (Gross)(reflects no deduction for fees, expenses or taxes)-2.66% 7.06% 2.01%

MSCI® All Country World (ex-US) Growth Index (Gross)(reflects no deduction for fees, expenses or taxes)0.49% 5.71% 1.87%

Lipper® Variable Insurance Products (VIP) International Multi-CapGrowth Funds Average

(reflects deductions for fees and expenses)-1.09% 6.18% 1.35%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: FIAM LLC (FIAM)Portfolio Managers: Jed Weiss, Portfolio Manager, began managing the Portfolio in 2015.Vincent Montemaggiore, effective June 15, 2017 has been named interim portfolio manager while Jed Weiss is on a leave ofabsence. Mr. Weiss is expected to return in the fourth quarter of 2017.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–47 Northwestern Mutual Series Fund, Inc.

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SUMMARY PROSPECTUSMAY 1, 2017 Research International Core Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016 are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is to seek capital appreciation.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.81%

Distribution and Service (12b-1) Fees None

Other Expenses 0.11%

Total Annual Portfolio Operating Expenses 0.92%

Fee Waiver(1) (0.05)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.87%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$89 $288 $504 $1,127

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 40.80% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio normally invests primarily in foreign equity securities, including emerging market equity securities. The Portfolionormally allocates its investments across different countries and regions, but the Portfolio may invest a large percentage of itsassets in issuers in a single country, a small number of countries, or a particular geographic region.

A team of investment research analysts selects investments for the Portfolio. The adviser allocates the Portfolio’s assets toanalysts by broad market sectors, which generally approximate the sector weightings in the MSCI EAFE® Index (the “Index”).While the Portfolio’s investments are normally allocated across broad market sectors that approximate the Index, the Portfolio

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Research International Core Portfolio

may at times invest a significant percentage of its assets in issuers in a small number of sectors, or industries within those sectors.The Portfolio does not, as a matter of policy, seek to concentrate in any particular industry. The Portfolio is not constrained to anyparticular investment style. The adviser may invest the Portfolio’s assets in the stocks of companies it believes to have aboveaverage earnings growth potential compared to other companies (growth companies), in the stocks of companies it believes areundervalued compared to their perceived worth (value companies), or in a combination of growth and value companies. ThePortfolio’s investments in equity securities may include small, medium and large capitalization companies, and could includecommon stocks, preferred stocks, securities convertible into stock and American Depositary Receipts (ADRs) and otherdepositary receipts for those securities.

The adviser uses a “bottom up” investment approach to buying and selling investments for the Portfolio, which emphasizesindividual stock selection. Investments are selected primarily based on fundamental analysis of individual issuers and their potentialin light of their financial condition, and market, economic, political and regulatory conditions. Factors considered may includeanalysis of an issuer’s earnings, cash flows, competitive position and management ability. Quantitative models that systematicallyevaluate an issuer’s valuation, price and earnings momentum, earnings quality and other factors, may also be considered.

The adviser may sell securities for a variety of reasons such as to seek to secure gains, limit losses, or redeploy assets intoopportunities believed to be more promising, among others.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Emerging Markets Risk – Investing in emerging market securities increases foreign investing risk, and may subject thePortfolio to more rapid and extreme changes in value or more losses than a fund that invests exclusively in U.S. securities or inforeign, developed countries. This risk is due to smaller markets, illiquidity, significant price and market volatility, currency,interest rate and commodity price fluctuations, restrictions on foreign investment, changes in tax policy, differing securitiesmarket structures, higher transaction costs, and various administrative difficulties, such as delays in executing, clearing andsettling portfolio transactions or in receiving payment of dividends.

• Equity Securities Risk – The value of equity securities, such as common and preferred stocks, could decline if the financialcondition of the companies the Portfolio is invested in declines or if overall market and economic conditions deteriorate.Equity securities generally have greater price volatility than fixed income securities.

• Foreign Currency Risk – The risk that foreign (non-U.S. dollar) currency denominated securities, or derivatives that provideexposure to foreign currencies, may be adversely affected by decreases in foreign currency values relative to the U.S. dollar.Investments in securities subject to foreign currency risk may have more rapid and extreme changes in value or more lossesthan investments in U.S. dollar denominated securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be less liquid, more volatile, and harderto value than U.S. securities.

• Geographic Concentration Risk – The Portfolio’s performance could be more volatile than that of a more geographicallydiversified fund and could be significantly impacted as a result of the Portfolio investing a large percentage of its assets inissuers located in a single country, a small number of countries, or a particular geographic region. Also, the Portfolio’sperformance may be more closely tied to the market, currency, economic, political, or regulatory conditions in those countriesor that region.

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• Investment Style Risk – A portfolio managed using a particular style of investing, such as growth or value or a combination ofboth, may underperform when the market does not favor the particular style used by the Portfolio. Different investment stylestend to shift in and out of favor, depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Liquidity Risk – Markets for small cap stocks and foreign securities, in particular emerging markets securities, may be lessliquid than markets for larger cap stocks and domestic securities, and therefore may be difficult to purchase or sell at anadvantageous time or price, if at all. These risks may be magnified during periods of economic turmoil or in an extendedeconomic downturn.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Sector Concentration Risk –To the extent the Portfolio invests a relatively high percentage of its assets in a particular sectoror industries within a sector, it will have greater exposure to the risks associated with that sector, including the risk that thesecurities of companies within the sector will underperform due to adverse economic conditions, regulatory or legislativechanges or increased competition affecting the sector. To the extent the Portfolio is underweight other sectors, the Portfoliorisks missing out on advances in those sectors.

• Small and Mid Cap Company Risk – Investing in small and mid cap stocks may cause greater risk of loss and pricefluctuation than investing in stocks of larger cap companies due to a more limited track record, narrower product markets, morelimited resources and less liquid trading markets. These stocks may be more volatile and more difficult to buy and sell thanstocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance, the returns of an additionalindex of securities with characteristics similar to those that the Portfolio typically holds, and the average returns of a peer groupof portfolios underlying variable insurance products with similar characteristics to those of the Portfolio. Returns are based onpast results and are not an indication of future performance. Neither the bar chart nor the table reflects the fees and expensesseparately charged by the variable annuity contract or variable life insurance policy separate account that invests in the Portfolioand returns would be lower if those fees and expenses were reflected.

2008

2009

2010

2011

2012

2013

2014

-50%

-40%

-30%

-20%

-10%

10%

20%

30%

40%

0%

-42.54%

-10.48%

30.82%

11.05%16.76%18.92%

-6.71%

2015

2016

-1.11%-1.12%

Best Qtr: 2nd – ‘09 24.05% Worst Qtr: 3rd – ‘08 -20.62%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Research International Core Portfolio-1.12% 4.84% -0.01%

MSCI® All Country World (ex-US) Index (Gross)(reflects no deduction for fees, expenses or taxes)5.01% 5.48% 0.60%

MSCI EAFE® (Europe-Australasia-Far East) Index (Gross)(reflects no deduction for fees, expenses or taxes)1.51% 7.02% 0.38%

Lipper® Variable Insurance Products (VIP) InternationalMulti-Cap Core Funds Average

(reflects deductions for fees and expenses)0.95% 5.85% —

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PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Massachusetts Financial Services Company (MFS®)Portfolio Managers: Jose Luis Garcia, Investment Officer of MFS, has managed the Portfolio since 2007.Thomas Melendez, Investment Officer of MFS, has managed the Portfolio since 2007.Victoria Higley, Investment Officer of MFS, has managed the Portfolio since 2016.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

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SUMMARY PROSPECTUSMAY 1, 2017 International Equity Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is long-term growth of capital. Any income realized will be incidental.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.66%

Distribution and Service (12b-1) Fees None

Other Expenses 0.06%

Total Annual Portfolio Operating Expenses 0.72%

Fee Waiver(1) (0.13)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.59%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$60 $217 $388 $882

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 16.25% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in equity securities and atleast 65% of net assets in securities of issuers from a minimum of three countries outside the U.S. The Portfolio may purchasesecurities in any foreign country, including those with developed markets and emerging markets. From time to time, based oneconomic conditions, the Portfolio may have significant investments in one or more countries or in particular sectors. ThePortfolio invests primarily in foreign common stocks, and may also invest in American Depositary Receipts (ADRs) and othersimilar depositary receipts.

The Portfolio’s investments in equity securities may include small, medium and large capitalization issues that the Portfolio’s adviserbelieves are undervalued. The strategy for the Portfolio will reflect a “bottom up”, value oriented and long-term investmentphilosophy. In choosing equity investments, the adviser will focus on the market price of a company’s securities in relation to thecompany’s long-term earnings (typically 5 years), asset value and cash flow potential. A company’s historical value measures,

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including price/earnings ratio, profit margins and liquidation value, will also be considered. In determining whether a company islocated in a country “outside” the U.S., the Portfolio’s adviser considers a variety of factors, such as location of companymanagement, location of the exchange on which the company’s stock is primarily traded, sources of revenue, and reporting currency.

The adviser may consider selling an equity security when it believes the security has become overvalued due to either its priceappreciation or changes in the company’s fundamentals, or when the adviser believes another security provides a more attractiveinvestment opportunity.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Emerging Markets Risk – Investing in emerging market securities increases foreign investing risk, and may subject thePortfolio to more rapid and extreme changes in value or more losses than a fund that invests exclusively in U.S. securities or inforeign, developed countries. This risk is due to smaller markets, illiquidity, significant price and market volatility, currency,interest rate and commodity price fluctuations, restrictions on foreign investment, changes in tax policy, differing securitiesmarket structures, higher transaction costs, and various administrative difficulties, such as delays in executing, clearing andsettling portfolio transactions or in receiving payment of dividends.

• Equity Securities Risk – The value of equity securities, such as common stocks, could decline if the financial condition of thecompanies the Portfolio is invested in declines or if overall market and economic conditions deteriorate. Equity securitiesgenerally have greater price volatility than fixed income securities.

• Foreign Currency Risk – The risk that foreign (non-U.S. dollar) currency denominated securities may be adversely affectedby decreases in foreign currency values relative to the U.S. dollar. Investments in securities subject to foreign currency riskmay have more rapid and extreme changes in value or more losses than investments in U.S. dollar denominated securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities and may be less liquid, more volatile, andharder to value than U.S. securities.

• Geographic Concentration Risk – The Portfolio’s performance could be more volatile than that of a more geographicallydiversified fund and could be significantly impacted as a result of the Portfolio investing a relatively large percentage of itsassets in issuers located in a single country, a small number of countries, or a particular geographic region. Also, the Portfolio’sperformance may be more closely tied to the market, currency, economic, political, or regulatory conditions in those countriesor that region.

• Investment Style Risk – A portfolio managed using a value style of investing, such as the Portfolio, may underperform whenthe market does not favor the particular style used by the Portfolio. Different investment styles tend to shift in and out of favor,depending on market conditions and investor sentiment.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Sector Concentration Risk – To the extent the Portfolio invests a relatively high percentage of its assets in a particular sector, itwill have greater exposure to the risks associated with that sector, including the risk that the securities of companies within thesector will underperform due to adverse economic conditions, regulatory or legislative changes or increased competition affectingthe sector. To the extent the Portfolio is underweight other sectors, the Portfolio risks missing out on advances in those sectors.

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• Small and Mid Cap Company Risk – Investing in small and mid cap stocks may cause greater risk of loss and pricefluctuation than investing in stocks of larger cap companies due to a more limited track record, narrower product markets, morelimited resources and less liquid trading markets. These stocks may be more volatile and more difficult to buy and sell thanstocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance, the returns of an additionalindex of securities with characteristics similar to those that the Portfolio typically holds, and the average returns of a peer groupof portfolios underlying variable insurance products with similar characteristics to those of the Portfolio. Returns are based onpast results and are not an indication of future performance. Neither the bar chart nor the table reflects the fees and expensesseparately charged by the variable annuity contract or variable life insurance policy separate account that invests in the Portfolioand returns would be lower if those fees and expenses were reflected.

2015

2014

2013

-50%

-30%

-40%

-20%

-10%

0%

10%

20%

30%

50%

40%

2007

2008

2009

2010

2011

2012

2016

18.06%

-43.78%

33.11%

7.67%

-10.10%

21.52%21.38%

-8.80%-2.21%

2.89%

Best Qtr: 2nd – ‘09 26.04% Worst Qtr: 4th – ‘08 -21.31%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

International Equity Portfolio2.89% 6.24% 1.47%

MSCI® All Country World (ex-US) Index (Gross)(reflects no deduction for fees, expenses or taxes)5.01% 5.48% 1.42%

MSCI EAFE® (Europe-Australasia-Far East) Index (Gross)(reflects no deduction for fees, expenses or taxes)1.51% 7.02% 1.22%

Lipper® Variable Insurance Products (VIP) International Multi-CapValue Funds Average

(reflects deductions for fees and expenses)5.52% 6.54% 0.86%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Templeton Investment Counsel, LLC (Templeton)Portfolio Manager: Antonio T. Docal, CFA, Executive Vice President, Deputy Director of Research and Portfolio Manager ofTempleton, joined Templeton in 2001 and has been a portfolio manager of the Portfolio since December 2014.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

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SUMMARY PROSPECTUSMAY 1, 2017 Emerging Markets Equity Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe Portfolio’s investment objective is to seek capital appreciation.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 1.11%

Distribution and Service (12b-1) Fees None

Other Expenses 0.14%

Total Annual Portfolio Operating Expenses 1.25%

Fee Waiver(1) (0.14)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 1.11%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$113 $383 $673 $1,499

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 47.33% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio normally invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities ofissuers that are tied economically to emerging market countries. The Portfolio invests primarily in common stocks, but may alsoinvest in other types of equity securities, including but not limited to, preferred stocks and American Depositary Receipts (ADRs)and other depositary receipts for those securities.

Emerging market countries include countries determined by the Portfolio’s adviser to have emerging market economies, takinginto account a number of factors, such as the country’s credit rating, its political and economic stability and the development of

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its financial and capital markets. Emerging market countries include every nation in the world except the United States, Canada,Japan, Australia, New Zealand and most countries located in Western Europe. A company is considered to be an emerging marketcompany if the adviser determines that the company meets one or more of the following criteria: the company

• is organized under the laws of, or has its principal office in an emerging market country;

• has its principal securities trading market in an emerging market country;

• derives the highest concentration of its annual revenue or earnings or assets from goods produced, sales made or servicesperformed in an emerging market country; or

• issues securities denominated in the currency of an emerging market country (and meets one of the other criteria set forth above).

The Portfolio may also invest in equity securities of issuers that are not tied economically to emerging market countries. Suchinvestments will not exceed 20% of the net assets of the Portfolio. The Portfolio may invest in securities denominated in U.S.Dollars and currencies of emerging market countries in which it is permitted to invest. The Portfolio typically has full currencyexposure to those markets in which it invests.

The Portfolio may invest in companies of any size. The Portfolio may invest in securities of any market sector and, from time totime, may hold a significant amount of securities of companies within a single sector. The adviser may invest a large percentageof the Portfolio’s assets in issuers in a single country, a small number of countries, or a particular geographic region.

The adviser employs a fundamental “bottom up” equity investment style, which is characterized by intensive, first-hand researchand disciplined company evaluation. Investments are identified for their long-term, fundamental value. The stock selectionprocess contains two filters, first quality and then price. In the quality filter, the adviser seeks to determine whether the companyis a business that has good growth prospects and a balance sheet that supports expansion. The team also considers how acompany’s corporate governance and risk management practices may affect that company’s long-term value. In the price filter,the adviser assesses the value of a company by reference to standard financial ratios, and estimates the value of the companyrelative to its market price and the valuations of companies within a relevant universe.

The Portfolio may sell a security when the adviser perceives that a company’s business direction or growth prospects havechanged or the company’s valuations are no longer attractive.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• ADR Risk – ADRs are receipts representing ownership of shares of a foreign issuer held by a U.S. bank or similar financialinstitution that entitle the holder to dividends and capital gains on the underlying foreign shares. ADRs are alternatives todirectly purchasing the underlying foreign securities in their national markets and currencies. They are subject to many of therisks associated with direct investments in the foreign securities, such as currency risk, political and economic risk and marketrisk, because their values depend on the performance of the non-dollar denominated underlying foreign securities. ThePortfolio is also subject to fees and the credit risk of the financial institution holding the ADRs.

• Emerging Markets Risk – Investing in emerging market securities increases foreign investing risk, and may subject thePortfolio to more rapid and extreme changes in value or more losses than a fund that invests exclusively in U.S. securities or inforeign, developed countries. This risk is due to smaller markets, illiquidity, significant price and market volatility, currency,interest rate and commodity price fluctuations, restrictions on foreign investment, changes in tax policy, differing securitiesmarket structures, higher transaction costs, and various administrative difficulties, such as delays in executing, clearing andsettling portfolio transactions or in receiving payment of dividends.

• Equity Securities Risk – The value of equity securities, such as common and preferred stocks, could decline if the financialcondition of the companies the Portfolio is invested in declines or if overall market and economic conditions deteriorate.Equity securities generally have greater price volatility than fixed income securities.

• Foreign Currency Risk – The risk that foreign (non-U.S. dollar) currency denominated securities, or derivatives that provideexposure to foreign currencies, may be adversely affected by decreases in foreign currency values relative to the U.S. dollar.Investments in securities subject to foreign currency risk may have more rapid and extreme changes in value or more lossesthan investments in U.S. dollar denominated securities.

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• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions or diplomatic developments. Foreign securities may be less liquid, more volatile, and harderto value than U.S. securities.

• Geographic Concentration Risk – The Portfolio’s performance could be more volatile than that of a more geographicallydiversified fund and could be significantly impacted as a result of the Portfolio investing a large percentage of its assets in issuerslocated in a single country, a small number of countries, or a particular geographic region. Also, the Portfolio’s performance maybe more closely tied to the market, currency, economic, political, or regulatory conditions in those countries or that region.

• Large Cap Company Risk – Investing in large cap stocks could cause the Portfolio to underperform in markets favoringfaster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow and may not have thesame growth potential as stocks with smaller capitalizations.

• Liquidity Risk – Markets for small and micro cap stocks and foreign securities, in particular emerging markets securities, maybe less liquid than markets for larger cap stocks and domestic securities, and therefore may be difficult to purchase or sell at anadvantageous time or price, if at all. These risks may be magnified during periods of economic turmoil or in an extendedeconomic downturn. The lack of active trading markets may make it difficult to obtain an accurate price for a security held bythe Portfolio.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Micro Cap Company Risk – Investing in micro cap stocks may cause the Portfolio to experience more rapid and extremechanges in value than a fund that invests solely in small, mid and large cap stocks due to a more limited track record, narrowerproduct markets, more limited resources higher risk of failure, and less liquid trading markets.

• Sector Concentration Risk – To the extent the Portfolio invests a relatively high percentage of its assets in a particular sector,it will have greater exposure to the risks associated with that sector, including the risk that the securities of companies withinthe sector will underperform due to adverse economic conditions, regulatory or legislative changes or increased competitionaffecting the sector. To the extent the Portfolio is underweight other sectors, the Portfolio risks missing out on advances inthose sectors.

• Small and Mid Cap Company Risk – Investing in small and mid cap stocks may cause greater risk of loss and pricefluctuation than investing in stocks of larger cap companies due to a more limited track record, narrower product markets, morelimited resources and less liquid trading markets. These stocks may be more volatile and more difficult to buy and sell thanstocks with larger capitalizations.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

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PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Prior to March 24, 2017, the sub-adviser to the Portfolio was different. Performance shown may have been different if the currentstrategy, and the current sub-adviser, had been in place during the periods shown. Returns are based on past results and are not anindication of future performance. Neither the bar chart nor the table reflects the fees and expenses separately charged by thevariable annuity contract or variable life insurance policy separate account that invests in the Portfolio and returns would be lowerif those fees and expenses were reflected.

2008

2009

2010

2011

2012

2013

2014

-80%

-60%

-40%

-20%

20%

40%

60%

80%

0%

-55.22%

-18.66%

69.73%

24.08% 18.83%9.06%

-5.15%-6.25%

2015

2016

-12.24%

Best Qtr: 2nd – ‘09 30.57% Worst Qtr: 3rd – ‘08 -30.50%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Emerging Markets Equity Portfolio9.06% 0.23% -0.34%

MSCI® Emerging Markets Index (Gross)(reflects no deduction for fees, expenses or taxes)11.60% 1.64% 1.52%

Lipper® Variable Insurance Products (VIP) Emerging MarketsFunds Average

(reflects deductions for fees and expenses)9.09% 1.56% —

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Aberdeen Asset Managers Limited (“Aberdeen”)Portfolio Managers: The Portfolio is managed using a team-based approach, with the following team members being jointly andprimarily responsible for the day-to-day management of the Portfolio:Hugh Young,Managing Director – Asia, has managed the Portfolio since March 2017.Devan Kaloo, Head of Equities, has managed the Portfolio since March 2017.Joanne Irvine, Head of Emerging Markets (ex-Asia), has managed the Portfolio since March 2017.Mark Gordon-James, CFA, Senior Investment Manager, has managed the Portfolio since March 2017.Flavia Cheong, CFA, Head of Equities – Asia (ex-Japan), has managed the Portfolio since March 2017

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the sale ofPortfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer to theprospectuses for the variable products for important information about compensation paid to financial intermediaries for sales ofvariable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–58

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SUMMARY PROSPECTUSMAY 1, 2017 Government Money Market Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is to realize maximum current income to the extent consistent with liquidity andstability of capital.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.30%

Distribution and Service (12b-1) Fees None

Other Expenses 0.02%

Total Annual Portfolio Operating Expenses 0.32%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$33 $103 $180 $406

PRINCIPAL INVESTMENT STRATEGIESAs a government money market portfolio, the Portfolio invests at least 99.5% of its total assets in cash, U.S. Treasury bills, notesand other obligations issued or guaranteed as to principal and interest by the U.S. Government, its agencies or instrumentalities,and repurchase agreements secured by such obligations or cash. The Portfolio may invest 100% of its total assets in suchrepurchase agreements. Under normal circumstances, the Portfolio will invest at least 80% of its net assets in obligations issuedor guaranteed as to principal and interest by the U.S. Government, its agencies or instrumentalities, and repurchase agreementssecured by such obligations. The Portfolio invests in a portfolio of securities maturing in 397 days or less (with certainexceptions) that will have a dollar-weighted average maturity of 60 days or less and a dollar-weighted average life of 120 days orless. The Portfolio may invest in variable and floating rate instruments, and transact in securities on a when-issued, delayeddelivery or forward commitment basis. The Portfolio seeks to maintain a net asset value of $1.00 per share.

PRINCIPAL RISKSThe main risks of investing in the Portfolio are identified below.

• Active Management Risk – The securities selected for the Portfolio may underperform the markets, relevant indices, orsecurities selected by other funds with similar investment objectives and investment strategies.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security or the counterparty to arepurchase agreement is unwilling or unable to meet its financial obligations.

• Income Risk – The risk that the Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds arereinvested in securities with different interest rates.

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Government Money Market Portfolio

• Interest Rate Risk – Prices of fixed income instruments generally rise and fall in response to changes in market interest rates.In a rising interest rate environment, the value of the Portfolio’s fixed income investments is likely to decline. A low interestrate environment poses additional risks to the Portfolio. Low yields on the Portfolio’s holdings may have an adverse impact onthe Portfolio’s ability to provide a positive yield to its shareholders or pay expenses out of Portfolio assets. Additionally,securities issued or guaranteed by the U.S. government, its agencies and instrumentalities have historically involved little riskof loss of principal if held to maturity. However, due to fluctuations in interest rates, the market value of such securities mayvary during the period you are invested in the Portfolio.

• Liquidity Risk – Investments for the Portfolio may be difficult to purchase or sell at an advantageous time or price, if at all.These risks may be magnified during periods of economic turmoil or in an extended economic downturn. The liquidityrequirements applicable to government money market funds are designed to help mitigate the potential impact of these risks.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Repurchase Agreements Risk – If the other party to a repurchase agreement defaults on its obligation under the agreement,the Portfolio may suffer delays and incur costs or lose money in exercising its rights under the agreement. These risks may beheightened if the other party is located outside of the U.S. If the seller fails to repurchase the security and the market value ofthe security declines, the Portfolio may lose money.

• Stable Net Asset Value Risk – The Portfolio may not be able to maintain a stable net asset value (“NAV”) of $1.00 per shareat all times. If the Portfolio fails to maintain a stable NAV (or there is a perceived threat of such failure), the Portfolio, alongwith other money market funds, could be subject to increased redemption activity.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

• U.S. Government Securities Risk – Not all obligations of the U.S. government, its agencies and instrumentalities are backedby the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency orinstrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or itsagencies or instrumentalities of a security held by the Portfolio does not apply to the market value of such security or to sharesof the Portfolio itself.

• Variable and Floating Rate Instrument Risk – Variable and floating rate securities provide for a periodic adjustment in theinterest rate paid on the obligations. The absence of an active market for these securities could make it difficult for thePortfolio to dispose of them if the issuer defaults.

• When-Issued and Delayed Delivery Transactions Risk – When issued and delayed delivery securities involve the risk thatthe security will lose value prior to its delivery. There is also the risk that the security will not be issued or that the other partyto the transaction will not meet its obligation. If this occurs, the Portfolio loses both the investment opportunity for the assets itset aside to pay for the security and any gain the security’s price.

You could lose money by investing in the Government Money Market Portfolio. Although the Portfolio seeks to preserve the valueof your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the Portfolio is not insured orguaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Portfolio’s sponsor has no legalobligation to provide financial support to the Portfolio, and you should not expect that the sponsor will provide financial supportto the Portfolio at any time.

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Government Money Market Portfolio

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods. Returns are based on past results and are not an indication of future performance. Prior to May 1, 2016, the Portfoliooperated as a prime money market fund and invested in certain types of securities that the Portfolio is no longer permitted to hold.Consequently, the performance information below may have been different if the current investment limitations had been ineffect during the period prior to the Portfolio’s conversion to a government money market fund. Neither the bar chart nor thetable reflects the fees and expenses separately charged by the variable annuity contract or variable life insurance policy separateaccount that invests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-1%

0%

1%

2%

6%

5%

4%

3%

2007

2008

5.28%

2009

2010

2011

2014

2013

2012

0.76%

2.76%

0.29% 0.14% 0.15% 0.10% 0.07%

2015

0.01%2016

0.13%

Best Qtr: 4th – ‘07 1.37% Worst Qtr: 4th – ‘13 0.00%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Government Money Market Portfolio0.13% 0.09% 0.96%

For the seven-day period ended March 31, 2017, the GovernmentMoney Market Portfolio’s yield was 0.44%.

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: BlackRock Advisors, LLC

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–61 Northwestern Mutual Series Fund, Inc.

Page 117: The Northwestern Mutual Life Insurance Company VariableLife

SUMMARY PROSPECTUSMAY 1, 2017 Short-Term Bond Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe primary investment objective of the Portfolio is to provide as high a level of current income as is consistent with prudentinvestment risk.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.34%

Distribution and Service (12b-1) Fees None

Other Expenses 0.09%

Total Annual Portfolio Operating Expenses 0.43%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$44 $138 $241 $542

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 36.61% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in a diversified portfolioof investment grade debt securities. The Portfolio may also invest up to 10% of net assets in non-investment grade, high yield/high risk bonds (so called “junk bonds”). Investment grade securities are generally securities rated investment grade by majorcredit rating agencies (BBB- or higher by S&P; Baa3 or higher by Moody’s; BBB- or higher by Fitch) and non-investment gradesecurities are generally securities rated below investment grade by major credit rating agencies (BB+ or lower by S&P; Ba1 orlower by Moody’s; BB+ or lower by Fitch), or, if unrated, determined by the Portfolio’s adviser to be of comparable quality.Also, the Portfolio may invest up to 20% of net assets in foreign securities, including those of issuers located in emergingmarkets, consistent with its investment objective. Foreign securities held by the Portfolio may consist of both U.S. dollar and non-U.S. dollar denominated securities. Debt securities may be of any maturity, but under normal market conditions, the Portfolio’saverage effective maturity will not exceed three years. The Portfolio primarily invests in corporate, government and mortgage-and asset-backed securities. The Portfolio may also utilize futures and forward contracts primarily to adjust the Portfolio’sduration and yield curve exposure, as well as hedge foreign currency exposure, swap agreements, including the purchase or sale

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of credit default swaps and interest rate swaps (to take a position on interest rates moving either up or down) in keeping with itsinvestment objective. Duration is a measure of the sensitivity of the price of a Portfolio’s fixed income securities to changes ininterest rates; the longer the duration, the more sensitive the price will be to changes in interest rates.

The adviser uses both a “top down” and “bottom up” investment approach to construct the portfolio of investments. The top downinvestment approach involves an evaluation by the adviser of the overall macroeconomic environment and its potential impact onthe level and direction of interest rates. The adviser then identifies sectors it believes have the best potential for performancebased on its economic outlook. The bottom up investment approach focuses on fundamental research of individual issuers.Investment decisions reflect the adviser’s outlook for interest rates and the economy, as well as the prices, yields, and creditquality of various securities in which the Portfolio may invest.

The adviser may sell a portfolio security for a variety of reasons, such as to adjust the Portfolio’s average maturity, duration, orcredit quality or to shift assets into and out of higher-yielding or lower-yielding securities or different sectors.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected and the adviser’squality determinations with respect to securities that are unrated by the major credit rating agencies may be inaccurate, whichcould cause the Portfolio to underperform other mutual funds or lose money.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security is unwilling or unable tomeet its financial obligations.

• Debt Obligations of Foreign Governments Risk – The issuer of the foreign debt or the governmental authorities that controlthe repayment of such debt may be unable or unwilling to repay principal or interest when due, and the Portfolio may havelimited recourse in the event of a default. The market prices of debt obligations of governments and their agencies, and thePortfolio’s net asset value, may be more volatile than prices of U.S. debt obligations.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that changes in the value of thederivatives may not correlate as intended with the underlying asset, rate or index, the risk of adverse price movements in themarket and the risk that the counterparty to a derivatives transaction fails to make the required payment or otherwise complywith the terms of the contract. Certain derivatives involve leverage, which could cause the Portfolio to lose more than theprincipal amount invested. Other risks include management, interest rate, and liquidity risks, and the risk of missedopportunities in other investments.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar and may be less liquid, more volatile, and harder to value than U.S.securities. The Portfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political,business and social frameworks to support securities markets.

• High Yield Debt Risk – High yield debt securities (so called “junk bonds”) in which the Portfolio invests have greater interest rateand credit risk, may be more difficult to sell or sell at a reasonable price, and have greater risk of loss than higher rated securities.

• Interest Rate Risk – Prices of fixed income instruments generally rise and fall in response to changes in market interest rates.In a rising interest rate environment, the value of the Portfolio’s fixed income investments is likely to decline. Currently,interest rates are near unprecedented historically low levels. A significant rise in interest rates over a short period of time couldcause significant losses in the market value of the Portfolio’s fixed income instruments. A portfolio with a longer averageportfolio duration will be more sensitive to changes in interest rates than a portfolio with a shorter average portfolio duration.

• Liquidity Risk – Fixed income and derivative investments can be difficult to purchase or sell at an advantageous time or price,if at all, during periods of reduced marketability for the investment or due to the size of the transaction. These risks may bemagnified during periods of economic turmoil or in an extended economic downturn or when investing in emerging markets.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

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Short-Term Bond Portfolio

• Mortgage- and Asset-Backed Securities Risk – The risks of investing in mortgage-related and other asset-backed securities,including interest rate risk, credit risk, liquidity risk, prepayment risk and extension risk.

• Prepayment and Extension Risk – Prepayment risk is the risk that principal on a debt obligation will be paid earlier thanscheduled or expected, which could reduce yield and market value of the security and shorten the Portfolio’s average effectivematurity. The rate of prepayments tends to increase as interest rates fall. Extension risk is the risk that, as interest rates rise,repayments on a debt obligation may occur more slowly than anticipated by the market and the obligation may remainoutstanding longer.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

• U.S. Government Securities Risk – Not all obligations of the U.S. government, its agencies and instrumentalities are backedby the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency orinstrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or itsagencies or instrumentalities of a security held by the Portfolio does not apply to the market value of such security or to sharesof the Portfolio itself.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2012

2008

2009

2010

2011

2013

2014

-5%

0%

5%

10%

2.71%

7.22%

3.63%

0.55%

2.07%

0.55% 0.38%

2015

2016

0.72%1.67%

Best Qtr: 1st – ‘09 2.53% Worst Qtr: 3rd – ‘08 -1.06%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Short-Term Bond Portfolio1.67% 1.07% 2.32%

Bloomberg Barclays® 1-3 Year U.S. Government/CreditBond Index

(reflects no deduction for fees, expenses or taxes)1.28% 0.92% 2.34%

Lipper® Variable Insurance Products (VIP) Short InvestmentGrade Debt Funds Average

(reflects deductions for fees and expenses)2.33% 1.45% —

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Sub-Adviser: T. Rowe Price Associates, Inc. (T. Rowe Price)Portfolio Manager: Michael F. Reinartz, CFA, Portfolio Manager and Chairman of T. Rowe Price’s Short-Term BondInvestment Advisory Committee, joined T. Rowe Price in 1996 and has managed the portfolio since 2015.

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TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–65 Northwestern Mutual Series Fund, Inc.

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SUMMARY PROSPECTUSMAY 1, 2017 Select Bond Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe primary investment objective of the Portfolio is to provide as high a level of total return as is consistent with prudentinvestment risk. A secondary objective is to seek preservation of shareholders’ capital.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.30%

Distribution and Service (12b-1) Fees None

Other Expenses 0.02%

Total Annual Portfolio Operating Expenses 0.32%

Fee Waiver(1) (0.01)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.31%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$32 $102 $179 $405

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 524.79% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in a diversified portfolioof investment grade debt securities with maturities exceeding one year. The Portfolio may also invest up to 10% of net assets innon-investment grade, high yield/high risk bonds (so called “junk bonds”). Investment grade securities are generally securitiesrated investment grade by major credit rating agencies (BBB- or higher by S&P; Baa3 or higher by Moody’s; BBB- or higher byFitch) and non-investment grade securities are generally securities rated below investment grade by major credit rating agencies(BB+ or lower by S&P; Ba1 or lower by Moody’s; BB+ or lower by Fitch), or, if unrated, determined by the Portfolio’s adviser tobe of comparable quality. The Portfolio invests primarily in U.S. Government obligations, corporate bonds and mortgage- andasset-backed securities, including mortgage dollar rolls, and may invest in Rule 144A securities. Also, the Portfolio may invest upto 20% of net assets in foreign securities, consistent with its investment objectives. Foreign securities held by the Portfolio consist

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primarily of U.S. dollar denominated securities but may also include non-U.S. dollar denominated securities. Debt securities maybe of any maturity or duration, but under normal market conditions, the Portfolio attempts to maintain an overall dollar-weightedaverage effective duration that is within 10% of the Bloomberg Barclays® U.S. Aggregate Index, which had a duration of 5.47years as of March 31, 2016. Duration is a measure of the sensitivity of the price of the Portfolio’s fixed income securities tochanges in interest rates; the longer the duration, the more sensitive the price will be to changes in interest rates. The Portfoliodoes not target an average effective maturity.

The adviser uses a fundamental, relative value investment approach to construct the portfolio of investments. The adviser investsin debt securities that it believes offer competitive returns and are undervalued, offering additional income and/or priceappreciation potential relative to other debt securities of similar credit quality and interest rate sensitivity. The adviser mayengage in active and frequent trading of portfolio securities to achieve its investment objectives.

The adviser may sell a portfolio security that has achieved its desired return or if the adviser believes the security or its sector hasbecome overvalued. The adviser may also sell a security if a more attractive opportunity becomes available or if the security is nolonger attractive due to its risk profile or as a result of changes in the overall market environment.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected and the adviser’squality determinations with respect to securities that are unrated by the major credit rating agencies may be inaccurate, whichcould cause the Portfolio to underperform other mutual funds or lose money.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security is unwilling or unable tomeet its financial obligations.

• Debt Obligations of Foreign Governments Risk – The issuer of the foreign debt or the governmental authorities that controlthe repayment of such debt may be unable or unwilling to repay principal or interest when due, and the Portfolio may havelimited recourse in the event of a default. The market prices of debt obligations of governments and their agencies, and thePortfolio’s net asset value, may be more volatile than prices of U.S. debt obligations.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. The risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be less liquid, more volatile, and harderto value than U.S. securities.

• High Portfolio Turnover Risk – Active and frequent trading may cause higher brokerage expenses and other transactioncosts, which may adversely affect the Portfolio’s performance.

• High Yield Debt Risk – High yield debt securities (so called “junk bonds”) in which the Portfolio invests have greater interest rateand credit risk, may be more difficult to sell or sell at a reasonable price, and have greater risk of loss than higher rated securities.

• Interest Rate Risk – Prices of fixed income instruments generally rise and fall in response to changes in market interest rates.In a rising interest rate environment, the value of the Portfolio’s fixed income investments is likely to decline. Currently,interest rates are near unprecedented historically low levels. A significant rise in interest rates over a short period of time couldcause significant losses in the market value of the Portfolio’s fixed income instruments. A portfolio with a longer averageportfolio duration will be more sensitive to changes in interest rates than a portfolio with a shorter average portfolio duration.

• Liquidity Risk – Fixed income investments, including Rule 144A securities, may be difficult to purchase or sell at anadvantageous time or price, if at all, during periods of reduced marketability for the investment or due to the size of thetransaction. These risks may be magnified during periods of economic turmoil or in an extended economic downturn.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mortgage- and Asset-Backed Securities Risk – The risks of investing in mortgage-related and other asset-backed securities,including mortgage dollar rolls, include interest rate risk, credit risk, liquidity risk, prepayment risk and extension risk.

• Prepayment and Extension Risk – Prepayment risk is the risk that principal on a debt obligation will be paid earlier than scheduledor expected, which could reduce yield and market value of the security and shorten the Portfolio’s average effective maturity. Therate of prepayments tends to increase as interest rates fall. Extension risk is the risk that, as interest rates rise, repayments on a debtobligation may occur more slowly than anticipated by the market and the obligation may remain outstanding longer.

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• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

• U.S. Government Securities Risk – Not all obligations of the U.S. government, its agencies and instrumentalities are backedby the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency orinstrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or itsagencies or instrumentalities of a security held by the Portfolio does not apply to the market value of such security or to sharesof the Portfolio itself.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2007

2008

-5%

0%

5%

10%

15%

2009

2010

2011

2012

2014

2015

2013

2016

6.39%

3.26%

9.37%

6.59% 7.16%

4.96%

-2.16%

5.56%

0.53%

3.06%

Best Qtr: 3rd – ‘09 4.19% Worst Qtr: 4th – ‘16 -2.79%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Select Bond Portfolio3.06% 2.35% 4.42%

Bloomberg Barclays® U.S. Aggregate Index(reflects no deduction for fees, expenses or taxes)2.65% 2.23% 4.34%

Lipper® Variable Insurance Products (VIP) Core BondFunds Average

(reflects deductions for fees and expenses)3.36% 2.86% 4.05%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Wells Capital Management, Inc. (WellsCap)Portfolio Managers: Troy Ludgood, Senior Portfolio Manager at WellsCap, has been with WellsCap since 2004 and has co-managed the Portfolio since 2014.Thomas O’Connor, CFA, Senior Portfolio Manager at WellsCap, has been with WellsCap since 2000 and has co-managed thePortfolio since 2014.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–68

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SUMMARY PROSPECTUSMAY 1, 2017 Long-Term U.S. Government Bond Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe Portfolio’s investment objective is to seek maximum total return, consistent with preservation of capital and prudentinvestment management.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentage ofthe value of your investment)

Management Fee 0.55%

Distribution and Service (12b-1) Fees None

Other Expenses 0.22%

Total Annual Portfolio Operating Expenses 0.77%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$79 $246 $428 $954

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 126.34% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio seeks to achieve its investment objective by investing under normal circumstances at least 80% of its net assets(plus any borrowings for investment purposes) in a diversified portfolio of fixed income securities that are issued or guaranteedby the U.S. Government, its agencies or government sponsored enterprises (“U.S. Government Securities”), which may berepresented by forwards or derivatives such as options, futures contracts or interest rate swap agreements (to take a position oninterest rates moving either up or down). Assets not invested in U.S. Government Securities may be invested in other types ofnon-government related investment grade fixed income instruments, such as corporate debt securities of U.S. issuers andmortgage- and asset-backed securities, subject to the quality restrictions described below. The Portfolio may also invest up to10% of its net assets in preferred stocks.

The Portfolio will normally have a minimum average portfolio duration of eight years and, for point of reference, the dollarweighted average maturity of the Portfolio, under normal circumstances, is expected to be more than ten years. Duration is ameasure of the sensitivity of the price of the Portfolio’s fixed income securities to changes in interest rates; the longer theduration, the more sensitive the price will be to changes in interest rates.

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The Portfolio may invest all of its assets in derivative instruments, such as options, futures contracts or interest rate swapagreements (to take a position on interest rates moving either up or down), in municipal bonds or in mortgage- or asset-backedsecurities, subject to the Portfolio’s objective and the Fund’s policies. The adviser may invest in derivatives at any time it deemsappropriate. It will generally do so when it believes that U.S. Government Securities are overvalued relative to derivativeinstruments or to adjust the overall duration of the Portfolio. The potential leverage created by use of derivatives may cause thePortfolio to be more sensitive to interest rate movements and thus more volatile than other long-term U.S. government bond fundsthat do not use derivatives.

The Portfolio may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis and may engage inshort sales. A short sale involves the sale of a security that is borrowed from a broker or other institution, and which must bepurchased in the market at a later date and returned to the lender. The Portfolio may, without limitation, seek to obtain marketexposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using otherinvestment techniques (such as buy backs or dollar rolls).

The “total return” sought by the Portfolio consists of income earned on the Portfolio’s investments, plus capital appreciation, ifany, which generally arises from decreases in interest rates or improving credit fundamentals for a particular sector or security.The Portfolio may engage in frequent and active trading of portfolio securities to achieve its investment objective, particularlyduring periods of volatile market movements.

The Portfolio’s investments in fixed income securities are limited to investment grade U.S. dollar denominated securities of U.S.issuers that are rated at least A by Moody’s or equivalently rated by S&P or Fitch, or, if unrated, determined by the adviser to beof comparable quality. If a downgrade in the rating of a security in which the Portfolio is invested causes it to fall outside theseparameters, the adviser will sell the impacted security as soon as reasonably practicable. In addition, with respect to thePortfolio’s investments in fixed income securities that are not U.S. Government Securities, the Portfolio may only invest up to10% of its total assets in securities rated A by Moody’s or equivalently rated by S&P or Fitch, or, if unrated, determined by theadviser to be of comparable quality, and may only invest up to 25% of its total assets in securities rated Aa by Moody’s orequivalently rated by S&P or Fitch or, if unrated, determined by the adviser to be of comparable quality.

The Portfolio may sell a position when, in the adviser’s opinion, it no longer represents a good value, when a superior risk/returnopportunity exists in a substitute position, or when it no longer fits within the Portfolio’s macroeconomic or structural strategy.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected and the adviser’squality determinations with respect to securities that are unrated by the major credit rating agencies may be inaccurate, whichcould cause the Portfolio to underperform other mutual funds or lose money.

• Counterparty Risk – The Portfolio may sustain a loss in the event the other party(s) in an agreement or a participant to atransaction, such as a broker or swap counterparty, defaults on a contract or fails to perform by failing to pay amounts due,failing to fulfill delivery conditions, or failing to otherwise comply with the terms of the contract. Counterparty risk is inherentin many transactions, including derivatives transactions.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security or the counterparty to aderivatives contract is unwilling or unable to meet its financial obligations.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The Portfolio’s use of derivatives involves risks different from, or possibly greater than, the risks associated withinvesting directly in securities or other traditional investments. Investments in derivatives may not have the intended effectsand may result in losses for the Portfolio that may not otherwise have occurred or missed opportunities for the Portfolio.Certain derivatives involve leverage, which could cause the Portfolio to lose more than the principal amount invested. Thederivatives could involve management, credit, interest rate, liquidity and market risks, and the risks of misplacing or impropervaluation. Changes in the value of the derivative may not correlate as intended with the underlying asset, rate or index. Inaddition, the Portfolio could sustain a loss in the event the counterparty to a derivatives transaction fails to make the requiredpayments or otherwise comply with the terms of the contract.

• Equity Securities Risk – The value of equity securities, such as common and preferred stocks, could decline if the financialcondition of the companies the Portfolio is invested in declines or if overall market and economic conditions deteriorate.Equity securities generally have greater price volatility than fixed income securities. Investments in rights and warrants may bemore volatile than the underlying investments in stocks.

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• High Portfolio Turnover Risk – Active and frequent trading may cause higher brokerage expenses and other transactioncosts, which may adversely affect the Portfolio’s performance.

• Inflation Risk – Your investment in the Portfolio may not provide enough income to keep pace with inflation.

• Interest Rate Risk – Prices of fixed income instruments generally rise and fall in response to changes in market interest rates.In a rising interest rate environment, the value of the Portfolio’s fixed income investments is likely to decline. Currently,interest rates are near unprecedented historically low levels. A significant rise in interest rates over a short period of time couldcause significant losses in the market value of the Portfolio’s fixed income instruments. A Portfolio with a longer averageportfolio duration will be more sensitive to changes in interest rates than a portfolio with a shorter average portfolio duration.

• Issuer Risk – The risk that the value of a security may decline for a reason directly related to the issuer, such as managementperformance, financial leverage and reduced demand for the issuer’s goods or services.

• Leverage Risk – Certain transactions, such as when issued, delayed delivery or forward commitments transactions, or the useof derivative transactions, may give rise to leverage, causing more volatility than if the Portfolio had not been leveraged.

• Liquidity Risk – Fixed income and derivative investments can be difficult to purchase or sell at an advantageous time or price,if at all, during periods of reduced marketability for the investment or due to the size of the transaction. These risks may bemagnified during periods of economic turmoil or in an extended economic downturn.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mortgage- and Asset-Backed Securities Risk – The risks of investing in mortgage-related and other asset-backed securities,including interest rate risk, credit risk, liquidity risk, prepayment risk and extension risk.

• Municipal Securities Risk – The value of municipal securities in which the Portfolio invests may be more sensitive to certainadverse conditions than other fixed income securities and the yields of municipal securities may move differently andadversely compared to the yields of the overall debt securities markets. Certain municipal securities may be or become highlyilliquid. Illiquidity may be exacerbated from time to time by market or economic events. Municipal securities may lose theirtax-exempt status if certain legal requirements are not met, or if federal or state tax laws change. The Portfolio’s investments incertain municipal securities with principal and interest payments that are made from the revenues of a specific project orfacility, and not general tax revenues, may have increased risks.

• Prepayment and Extension Risk – Prepayment risk is the risk that principal on a debt obligation will be paid earlier thanscheduled or expected, which could reduce yield and market value of the security and shorten the Portfolio’s average effectivematurity. The rate of prepayments tends to increase as interest rates fall. Extension risk is the risk that, as interest rates rise,repayments on a debt obligation may occur more slowly than anticipated by the market and the obligation may remainoutstanding longer.

• Short Sale Risk – The risk of entering into short sales, including the potential loss of more money than the actual cost of theinvestment, and the risk that the third party to the short sale may fail to honor its contract terms, causing a loss to the Portfolio.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

• U.S. Government Securities Risk – Not all obligations of the U.S. government, its agencies and instrumentalities are backedby the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency orinstrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or itsagencies or instrumentalities of a security held by the Portfolio does not apply to the market value of such security or to sharesof the Portfolio itself.

• When Issued, Delayed Delivery and Forward Commitment Risk – When issued, delayed delivery purchases and forwardcommitment transactions involve a risk of loss if the value of the securities declines prior to the settlement date. This risk is inaddition to the risk that the Portfolio’s other assets will decline in value. Therefore, these transactions may result in a form ofleverage and increase the Portfolio’s overall investment exposure.

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PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2012

2008

2009

2010

2011

2013

2014

-20%

-10%

0%

20%

10%

30%

20.76%

-6.98%

-13.27%

-1.47%

10.62%

28.92%

3.75%

23.73%

1.09%2015

2016

Best Qtr: 3rd – ‘11 22.86% Worst Qtr: 4th – ‘16 -11.41%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Long-Term U.S. Government Bond Portfolio1.09% 2.09% 6.92%

Bloomberg Barclays® Long-Term U.S. Treasury Index(reflects no deduction for fees, expenses or taxes)1.33% 2.52% 6.70%

Morningstar® US Insurance Fund Long Government Average(reflects deductions for fees and expenses)0.60% 1.71% —

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Pacific Investment Management Company LLC (PIMCO)Portfolio Managers: Stephen Rodosky, joined PIMCO in 2001 and is a Managing Director in PIMCO’s Newport Beach office.He has managed the Portfolio since 2007.Michael Cudzil, joined PIMCO in 2012 and is an Executive Vice President in PIMCO’s Newport Beach office. He has managedthe Portfolio since February 2016.Josh Thimons, joined PIMCO in 2010 and is a Managing Director in PIMCO’s Newport Beach office. He has managed thePortfolio since February 2016.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–72

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SUMMARY PROSPECTUSMAY 1, 2017 Inflation Protection Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe Portfolio’s investment objective is to pursue total return using a strategy that seeks to protect against U.S. inflation.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.55%

Distribution and Service (12b-1) Fees None

Other Expenses 0.08%

Total Annual Portfolio Operating Expenses 0.63%

Fee Waiver(1) (0.04)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.59%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$60 $198 $347 $783

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 33.80% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESThe Portfolio invests substantially all of its assets in investment-grade debt securities. To help protect against U.S. inflation (asmeasured by the change in the Consumer Price Index over time), under normal conditions, the Portfolio will invest over 50% of itsnet assets (plus any borrowings for investment purposes) in inflation-indexed debt securities. These securities include inflation-indexed U.S. Treasury Securities, inflation-indexed securities issued by U.S. government agencies and instrumentalities other thanthe U.S. Treasury, and inflation-indexed securities issued by domestic and foreign corporations and governments, and may includethose located in emerging markets. Inflation-indexed securities are designed to protect the future purchasing power of the money

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invested in them. The Portfolio also may invest in fixed income securities that are not inflation-indexed, including mortgage- andasset-backed securities. Investment grade securities are generally securities rated investment grade by major credit rating agencies(BBB- or higher by S&P; Baa3 or higher by Moody’s; BBB- or higher by Fitch) or, if unrated, determined by the Portfolio’sadviser to be of comparable quality.

Due to Internal Revenue Code provisions and regulations governing insurance product funds, no more than 55% of the Portfolio’sassets may be invested in securities issued by the same entity. Because the number of inflation-indexed debt securities issued byother entities is limited, at times the Portfolio may have a substantial position in non-inflation-indexed securities. To seek toreduce the impact of this limitation, the adviser may purchase (long) inflation swap agreements to manage or reduce the risk ofthe effects of inflation with respect to the Portfolio’s position in non-inflation-indexed securities. The Portfolio is classified as“non-diversified” under the Investment Company Act of 1940, as amended, which means it may hold larger positions in a singlesecurity or smaller number of securities than a “diversified” fund.

The adviser is not limited to a specific weighted average maturity or duration range. However, the adviser monitors thePortfolio’s weighted average maturity and duration and seeks to adjust it as appropriate, taking into account market conditions,the current inflation rate and other relevant factors.

The Portfolio may invest up to 20% of its total assets in securities denominated in foreign currencies and may invest beyond thislimit in U.S. dollar denominated securities of foreign issuers. The Portfolio may hedge some or all of its foreign currency byutilizing foreign currency contracts and futures to seek to reduce the risk of loss due to fluctuations in the currency exchangerates, when the adviser deems it to be advantageous.

The Portfolio may sell a security for a variety of reasons, including its assessment of the security’s relative attractiveness in light of itsevaluation of current economic conditions or the risk of inflation, or to manage the Portfolio’s maturity and credit quality standards.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective and there is no guarantee of inflation protection. The main risks of investingin this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected and the adviser’squality determinations with respect to securities that are unrated by the major credit rating agencies may be inaccurate, whichcould cause the Portfolio to underperform other mutual funds or lose money.

• Counterparty Risk – The Portfolio may sustain a loss in the event the other party(s) in an agreement or a participant to atransaction, such as a broker or swap counterparty, defaults on a contract or fails to perform by failing to pay amounts due,failing to fulfill delivery conditions, or failing to otherwise comply with the terms of the contract. Counterparty risk is inherentin many transactions, including derivatives transactions.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security is unwilling or unable tomeet its financial obligations.

• Debt Obligations of Foreign Governments Risk – The issuer of the foreign debt or the governmental authorities that controlthe repayment of such debt may be unable or unwilling to repay principal or interest when due, and the Portfolio may havelimited recourse in the event of a default. The market prices of debt obligations of governments and their agencies, and thePortfolio’s net asset value, may be more volatile than prices of U.S. debt obligations. In addition, unlike debt instrumentsissued by the U.S. Treasury, inflation-linked bonds issued by corporations or foreign governments do not generally provideprincipal protection, and in a deflationary environment, such bonds may result in the loss of principal.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that the counterparty to a derivativestransaction fails to make the required payment or otherwise comply with the terms of the contract, the risk that changes in the valueof the derivatives may not correlate as intended with the underlying asset, rate or index, and the risk of adverse price movements inthe market. Certain derivatives involve leverage, which could cause the Portfolio to lose more than the principal amount invested.Other risks include management, interest rate, liquidity risks and the risk of missed opportunities in other investments.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar, or in the case of hedged positions, that the U.S. dollar will decline in value

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relative to the currency being hedged, and may be less liquid, more volatile, and harder to value than U.S. securities. ThePortfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political, business andsocial frameworks to support securities markets.

• Inflation Risk – Your investment in the Portfolio may not provide enough income to keep pace with inflation. To the extentthat the Portfolio holds investments in non-inflation-linked debt securities, as noted above, that portion of the Portfolio will notbe automatically protected from inflation.

• Interest Rate Risk – Prices of fixed income instruments, including inflation-indexed debt securities, generally rise and fall inresponse to changes in market interest rates. In a rising interest rate environment, the value of the Portfolio’s fixed incomeinvestments is likely to decline. Currently, interest rates are near unprecedented historically low levels. A significant rise ininterest rates over a short period of time could cause significant losses in the market value of the Portfolio’s fixed incomeinstruments. A portfolio with a longer average portfolio duration will be more sensitive to changes in interest rates than aportfolio with a shorter average portfolio duration.

• Liquidity Risk – Fixed income and derivative investments can be difficult to purchase or sell at an advantageous time or price,if at all, during periods of reduced marketability for the investment or due to the size of the transaction. These risks may bemagnified during periods of economic turmoil or in an extended economic downturn or when investing in emerging markets.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mortgage- and Asset-Backed Securities Risk – The risks of investing in mortgage-related and other asset-backed securities,including interest rate risk, credit risk, liquidity risk, prepayment risk and extension risk.

• Non-Diversification Risk – The Portfolio is classified as a non-diversified fund and is permitted to invest a greater portion ofits assets in a single security or a small number of securities. As a result, an increase or decrease in the value of single securityheld by the Portfolio may have a greater impact on the Portfolio’s net asset value and total return, and, the Portfolio’sperformance could be more volatile than the performance of funds that hold a greater number of securities.

• Prepayment and Extension Risk – Prepayment risk is the risk that principal on a debt obligation will be paid earlier thanscheduled or expected, which could reduce yield and market value of the security and shorten the Portfolio’s average effectivematurity. The rate of prepayments tends to increase as interest rates fall. Extension risk is the risk that, as interest rates rise,repayments on a debt obligation may occur more slowly than anticipated by the market and the obligation may remainoutstanding longer.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

• U.S. Government Securities Risk – Not all obligations of the U.S. government, its agencies and instrumentalities are backedby the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency orinstrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or itsagencies or instrumentalities of a security held by the Portfolio does not apply to the market value of such security or to sharesof the Portfolio itself.

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PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the table reflects thefees and expenses separately charged by the variable annuity contract or variable life insurance policy separate account thatinvests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2008

2009

2010

2011

2012

2013

2014

-10%

-5%

5%

10%

15%

0%-1.38%

9.98%

5.60%7.35%

-8.33%

-2.20%

11.93%

3.14%4.68%

2015

2016

Best Qtr: 4th – ‘07 4.33% Worst Qtr: 2nd – ‘13 -6.92%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Inflation Protection Portfolio4.68% 0.77% 3.71%

Bloomberg Barclays® U.S. Treasury Inflation Protected Securities(TIPS) Index

(reflects no deduction for fees, expenses or taxes)4.68% 0.89% 4.17%

Lipper® Variable Insurance Products (VIP) Inflation ProtectedBond Funds Average

(reflects deductions for fees and expenses)4.96% 0.76% —

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: American Century Investment Management, Inc. (American Century)Portfolio Managers: Brian Howell, Vice President and Senior Portfolio Manager, has served American Century as a portfoliomanager since 1996 and has managed the Portfolio since 2008.James E. Platz, CFA, Vice President and Senior Portfolio Manager, has served American Century as a portfolio manager since2003 and has managed the Portfolio since 2008.Robert V. Gahagan, Senior Vice President and Senior Portfolio Manager, has served American Century as a portfolio managersince 1991 and has managed the Portfolio since 2007.Miguel Castillo, Portfolio Manager, has served American Century as a portfolio manager since 2014 and has managed thePortfolio since 2015.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

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SUMMARY PROSPECTUSMAY 1, 2017 High Yield Bond Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is to achieve high current income and capital appreciation.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.42%

Distribution and Service (12b-1) Fees None

Other Expenses 0.05%

Total Annual Portfolio Operating Expenses 0.47%

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.Although your actual costs may be higher or lower, based onthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$48 $151 $263 $591

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 35.58% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in non-investment gradedebt securities. Non-investment grade securities are generally securities rated below investment grade by major credit ratingagencies (BB+ or lower by S&P; Ba1 or lower by Moody’s; BB+ or lower by Fitch), or, if unrated, determined by the Portfolio’sadviser to be of comparable quality. There is no minimal acceptable rating for a security to be purchased or held by the Portfolio.The Portfolio may invest up to 30% of net assets in non-investment grade foreign securities, including those of issuers located inemerging markets, consistent with its investment objective. Foreign securities held by the Portfolio consist primarily of U.S.dollar denominated securities but may also include non-U.S. dollar denominated securities.

The securities in which the Portfolio primarily invests are considered speculative and are sometimes known as “junk bonds.”These securities tend to offer higher yields than higher rated securities of comparable maturities primarily because of the market’sgreater uncertainty about the issuer’s ability to make all required interest and principal payments, and therefore about the returnsthat will in fact be realized by the Portfolio.

The adviser selects securities that it believes have attractive investment characteristics and seeks to minimize default risk and otherrisks through careful security selection and diversification. The adviser’s securities selection process consists of a credit-intensive,

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fundamental analysis of the issuer. The adviser’s analysis focuses on the issuer’s financial condition, business and product strength,competitive position and management expertise. Further, the adviser considers current economic, financial market and industryfactors, which may affect the issuer. The adviser does not limit the Portfolio’s investments to securities of a particular maturity rangeand does not target an average effective maturity or duration.

The adviser strives to adhere to a strong sell discipline and generally effects a sale if it believes a security’s future total return hasbecome less attractive relative to other securities, the company begins to perform poorly, the industry outlook changes, or anyother event occurs that changes the adviser’s conclusion.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected and the adviser’squality determinations with respect to securities that are unrated by the major credit rating agencies may be inaccurate, whichcould cause the Portfolio to underperform other mutual funds or lose money.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security is unwilling or unable tomeet its financial obligations.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Foreign securities may be adversely affected by decreases inforeign currency values relative to the U.S. dollar, or in the case of hedged positions, that the U.S. dollar will decline in valuerelative to the currency being hedged, and may be less liquid, more volatile, and harder to value than U.S. securities. ThePortfolio’s investments in emerging markets heighten these risks due to a lack of established legal, political, business andsocial frameworks to support securities markets.

• High Yield Debt Risk – High yield debt securities (so called “junk bonds”) in which the Portfolio invests have greater interest rateand credit risk, may be more difficult to sell or sell at a reasonable price, and have greater risk of loss than higher rated securities.

• Inflation Risk – Your investment in the Portfolio may not provide enough income to keep pace with inflation.

• Interest Rate Risk – Prices of fixed income instruments generally rise and fall in response to changes in market interest rates.In a rising interest rate environment, the value of the Portfolio’s fixed income investments is likely to decline. Currently,interest rates are near unprecedented historically low levels. A significant rise in interest rates over a short period of time couldcause significant losses in the market value of the Portfolio’s fixed income instruments. Duration measures the price sensitivityof a fixed income instrument to changes in interest rates. A portfolio with a longer average portfolio duration will be moresensitive to changes in interest rates than a portfolio with a shorter average portfolio duration.

• Liquidity Risk – High yield debt securities may be difficult to purchase or sell at an advantageous time or price, if at all. Theserisks may be magnified during periods of economic turmoil or in an extended economic downturn or when investing inemerging markets.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

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PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance as well as with the averagereturns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of the Portfolio.In addition, the broader market exposure which results from the Index’s 2% issuer cap more closely aligns with the Portfolio’sinvestment objective and strategy. Returns are based on past results and are not an indication of future performance. Neither thebar chart nor the table reflects the fees and expenses separately charged by the variable annuity contract or variable life insurancepolicy separate account that invests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-30%

-15%

0%

15%

30%

60%

45%

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2.38%

-21.35%

45.39%

14.56%

4.59%

13.89%5.84%

1.18%

-1.36%

14.59%

Best Qtr: 2nd – ‘09 18.75% Worst Qtr: 4th – ‘08 -14.12%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

High Yield Bond Portfolio14.59% 6.63% 6.82%

Bloomberg Barclays® U.S. Corporate High Yield 2% IssuerCapped Index

(reflects no deduction for fees, expenses or taxes)17.13% 7.36% 7.55%

Lipper® Variable Insurance Products (VIP) High YieldFunds Average

(reflects deductions for fees and expenses)13.08% 6.20% 6.06%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Sub-Adviser: Federated Investment Management Company (Federated)Portfolio Manager: Mark E. Durbiano, CFA, Senior Portfolio Manager and Senior Vice President of Federated, has been withFederated since 1982 and has managed the Portfolio since 2014.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–79 Northwestern Mutual Series Fund, Inc.

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SUMMARY PROSPECTUSMAY 1, 2017 Multi-Sector Bond Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe Portfolio’s investment objective is to seek maximum total return, consistent with prudent investment management.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.78%

Distribution and Service (12b-1) Fees None

Other Expenses 0.07%

Total Annual Portfolio Operating Expenses 0.85%

Fee Waiver(1) (0.07)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1) 0.78%

(1) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$80 $264 $465 $1,043

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 42.81% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESNormally, the Portfolio seeks to achieve its investment objective by investing at least 80% of its net assets (plus any borrowingsfor investment purposes) in a diversified portfolio of fixed income instruments of varying maturities, which may be representedby forwards or derivatives such as options, futures contracts or swap agreements, including the purchase or sale of credit defaultswaps, and interest rate swaps (to take a position on interest rates moving either up or down). The average portfolio duration ofthe Portfolio normally varies from three to eight years, based on the adviser’s forecast for interest rates. Duration is a measure ofthe sensitivity of the price of the Portfolio’s fixed income securities to changes in interest rates; the longer the duration, the moresensitive the price will be to changes in interest rates.

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The Portfolio may invest all of its assets in high yield securities subject to a maximum of 10% of its total assets in securities ratedbelow B by Moody’s or equivalently rated by S&P or Fitch or, if unrated, determined by the Portfolio’s adviser to be ofcomparable quality (so called “junk bonds”). The Portfolio may invest, without limitation, in securities denominated in foreigncurrencies and U.S. dollar denominated securities of foreign issuers. In addition, the Portfolio may invest without limit in fixedincome securities of issuers that are economically tied to emerging securities markets. The Portfolio may invest in illiquidsecurities. The Portfolio may also invest up to 10% of its net assets in preferred stocks.

The Portfolio may invest all of its assets in derivative instruments, such as options, futures contracts or swap agreementsincluding the purchase or sale of credit defaults swaps, and interest rate swaps (to take a position on interest rates moving eitherup or down), in municipal bonds, or in mortgage- or asset-backed securities, subject to the Portfolio’s objective and policies. Theadviser may invest in derivatives at any time it deems appropriate, generally when relative value and liquidity conditions makethese investments more attractive relative to cash bonds.

The Portfolio may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis and may engage inshort sales. A short sale involves the sale of a security that is borrowed from a broker or other institution, and which must bepurchased in the market at a later date and returned to the lender. The Portfolio may, without limitation, seek to obtain marketexposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using otherinvestment techniques (such as buy backs or dollar rolls).

The “total return” sought by the Portfolio consists of income earned on the Portfolio’s investments, plus capital appreciation, ifany, which generally arises from a decrease in interest rates or improving credit fundamentals for a particular sector or security.The Portfolio may engage in frequent and active trading of portfolio securities to achieve its investment objective, particularlyduring periods of volatile market movements.

In selecting securities for a Portfolio, the adviser develops an outlook for interest rates, foreign currency exchange rates and theeconomy, analyzes credit and call risks, which involves both macro and fundamental analysis. The proportion of a Portfolio’sassets committed to investment in securities with particular characteristics (such as quality, sector, interest rate or maturity) variesbased on the adviser’s outlook for the U.S. and foreign economies, the financial markets and other factors.

The adviser attempts to identify areas of the bond market that are undervalued relative to the rest of the market. The adviseridentifies these areas by grouping bonds into the following sectors: money markets, governments, corporates, mortgages, asset-backed and international. Sophisticated proprietary software then assists in evaluating sectors and pricing specific securities.Once investment opportunities are identified, the adviser will shift assets among sectors depending upon changes in relativevaluations and credit spreads.

The Portfolio may sell a position when, in the adviser’s opinion, it no longer represents a good value, when a superior risk/returnopportunity exists in a substitute position, or when it no longer fits within the Portfolio’s macroeconomic or structural strategy.

PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected and the adviser’squality determinations with respect to securities that are unrated by the major credit rating agencies may be inaccurate, whichcould cause the Portfolio to underperform other mutual funds or lose money.

• Counterparty Risk – The Portfolio may sustain a loss in the event the other party(s) in an agreement or a participant to atransaction, such as a broker or swap counterparty, defaults on a contract or fails to perform by failing to pay amounts due,failing to fulfill delivery conditions, or failing to otherwise comply with the terms of the contract. Counterparty risk is inherentin many transactions, including derivatives transactions.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security is unwilling or unable tomeet its financial obligations.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The Portfolio’s use of derivatives involves risks different from, or possibly greater than, the risks associated withinvesting directly in securities or other traditional investments. Investments in derivatives may not have the intended effectsand may result in losses for the Portfolio that may not otherwise have occurred or missed opportunities for the Portfolio.Certain derivatives involve leverage, which could cause the Portfolio to lose more than the principal amount invested.Derivatives could involve management, credit, interest rate, liquidity and market risks, and the risks of misplacing or improper

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valuation. Changes in the value of the derivative may not correlate as intended with the underlying asset, rate or index. Inaddition, the Portfolio could sustain a loss in the event the counterparty to a derivatives transaction fails to make the requiredpayments or otherwise comply with the terms of the contract.

• Equity Securities Risk – The value of equity securities, such as common and preferred stocks, could decline if the financialcondition of the companies the Portfolio is invested in declines or if overall market and economic conditions deteriorate.Equity securities generally have greater price volatility than fixed income securities. Investments in rights and warrants may bemore volatile than the underlying investments in stocks.

• Foreign Currency Risk – The risk that foreign (non-U.S. dollar) currency denominated securities, or derivatives that provideexposure to foreign currencies, may be adversely affected by decreases in foreign currency values relative to the U.S. dollar, or,in the case of hedged positions, that the U.S. dollar will decline in value relative to the currency being hedged. Investments insecurities subject to foreign currency risk may have more rapid and extreme changes in value or more losses than investmentsin U.S. dollar denominated securities.

• Foreign Investing Risk – Investing in foreign securities may subject the Portfolio to more rapid and extreme changes in valueor more losses than a fund that invests exclusively in U.S. securities. This risk is due to potentially smaller markets, differingreporting, accounting and auditing standards, and nationalization, expropriation or confiscatory taxation, currency blockage,political and economic conditions, or diplomatic developments. Investments in emerging markets impose risks different from,and greater than, investments in developed markets. Foreign securities may be less liquid, more volatile, and harder to valuethan U.S. securities. The Portfolio’s investments in emerging markets heighten these risks due to a lack of established legal,political, business and social frameworks to support securities markets.

• High Portfolio Turnover Risk – Active and frequent trading may cause higher brokerage expenses and other transactioncosts, which may adversely affect the Portfolio’s performance.

• High Yield Debt Risk – High yield debt securities (so called “junk bonds”) in which the Portfolio invests have greater interest rateand credit risk, may be more difficult to sell or sell at a reasonable price, and have greater risk of loss than higher rated securities.

• Inflation Risk – Your investment in the Portfolio may not provide enough income to keep pace with inflation.

• Interest Rate Risk – Prices of fixed income instruments generally rise and fall in response to changes in market interest rates.In a rising interest rate environment, the value of the Portfolio’s fixed income investments is likely to decline. Currently,interest rates are near unprecedented historically low levels. A significant rise in interest rates over a short period of time couldcause significant losses in the market value of the Portfolio’s fixed income instruments. A portfolio with a longer averageportfolio duration will be more sensitive to changes in interest rates than a portfolio with a shorter average portfolio duration.

• Issuer Risk – The risk that the value of a security may decline for a reason directly related to the issuer, such as managementperformance, financial leverage and reduced demand for the issuer’s goods or services.

• Leverage Risk – Certain transactions, such as when issued, delayed delivery or forward commitments transactions, orderivative transactions, may give rise to leverage, causing more volatility than if the Portfolio had not been leveraged.

• Liquidity Risk – Fixed income and derivative investments can be difficult to purchase or sell at an advantageous time or price,if at all, during periods of reduced marketability for the investment or due to the size of the transaction. These risks may bemagnified during periods of economic turmoil or in an extended economic downturn or when investing in emerging markets.

• Market Risk – The risk that the market price of securities owned by the Portfolio may go up or down, sometimes rapidly orunpredictably, due to factors affecting securities markets generally or particular industries.

• Mortgage- and Asset-Backed Securities Risk – The risks of investing in mortgage-related and other asset-backed securities,including interest rate risk, credit risk, liquidity risk, prepayment risk and extension risk.

• Municipal Securities Risk – The value of municipal securities in which the Portfolio invests may be more sensitive to certainadverse conditions than other fixed income securities and the yields of municipal securities may move differently andadversely compared to the yields of the overall debt securities markets. Certain municipal securities may be or become highlyilliquid. Illiquidity may be exacerbated from time to time by market or economic events. Municipal securities may lose theirtax-exempt status if certain legal requirements are not met, or if federal or state tax laws change. The Portfolio’s investments incertain municipal securities with principal and interest payments that are made from the revenues of a specific project orfacility, and not general tax revenues, may have increased risks.

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• Prepayment and Extension Risk – Prepayment risk is the risk that principal on a debt obligation will be paid earlier than scheduledor expected, which could reduce yield and market value of the security and shorten the Portfolio’s average effective maturity. The rateof prepayments tends to increase as interest rates fall. Extension risk is the risk that, as interest rates rise, repayments on a debtobligation may occur more slowly than anticipated by the market and the obligation may remain outstanding longer.

• Short Sale Risk – The risk of entering into short sales, including the potential loss of more money than the actual cost of theinvestment, and the risk that the third party to the short sale may fail to honor its contract terms, causing a loss to the Portfolio.

• Underlying Portfolio Risk – The Portfolio may serve as an investment option, or “Underlying Portfolio,” for other portfoliosof Northwestern Mutual Series Fund, Inc. that are managed as “fund of funds.” As a result, from time to time, the Portfoliomay experience relatively large investments or redemptions from those other portfolios and could be required to invest cash orsell securities at a time when it is not advantageous to do so.

• U.S. Government Securities Risk – Not all obligations of the U.S. government, its agencies and instrumentalities are backedby the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency orinstrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or itsagencies or instrumentalities of a security held by the Portfolio does not apply to the market value of such security or to sharesof the Portfolio itself.

• When Issued, Delayed Delivery and Forward Commitment Risk – When issued, delayed delivery purchases and forwardcommitment transactions involve a risk of loss if the value of the securities declines prior to the settlement date. This risk is inaddition to the risk that the Portfolio’s other assets will decline in value. Therefore, these transactions may result in a form ofleverage and increase the Portfolio’s overall investment expense.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance, the returns of an equallyweighted blend of certain indices of securities with characteristics similar to those that the Portfolio typically holds, and theaverage returns of a peer group of portfolios underlying variable insurance products with similar characteristics to those of thePortfolio. Returns are based on past results and are not an indication of future performance. Neither the bar chart nor the tablereflects the fees and expenses separately charged by the variable annuity contract or variable life insurance policy separateaccount that invests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2008

2009

2010

2011

2012

2013

2014

2015

2016

-10%

0%

10%

20%

30%

-6.86%

22.08%

13.19%

4.99%

14.94%

-1.58% -2.22%

3.25%

11.09%

Best Qtr: 3rd – ‘09 9.27% Worst Qtr: 3rd – ‘08 -4.77%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs

SinceInception on04/30/07

Multi-Sector Bond Portfolio11.09% 4.88% 5.84%

Bloomberg Barclays® Global Credit Hedged USD Index(reflects no deduction for fees, expenses or taxes)7.34% 5.13% 5.28%

331⁄3% each of the following three indices: Bloomberg Barclays®

Global Aggregate – Credit Component ex Emerging Markets,Hedged USD; BofA Merrill Lynch® Global High Yield BB-BRated Constrained Developed Markets Index, Hedged USD;and JPMorgan® EMBI Global

(reflects no deduction for fees, expenses or taxes)9.81% 5.99% 6.32%

Morningstar® US Insurance Fund Multisector Bond Average(reflects deductions for fees and expenses)7.44% 4.48% —

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PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLCSub-Adviser: Pacific Investment Management Company LLC (PIMCO)Portfolio Managers: Eve Tournier, Executive Vice President of PIMCO, joined PIMCO in 2008 and has managed the Portfoliosince 2010.Daniel J. Ivascyn, Group Chief Investment Officer and Managing Director of PIMCO, joined PIMCO in 1998 and has managedthe Portfolio since May 2016.Alfred T. Murata, Managing Director of PIMCO, joined PIMCO in 2001 and has managed the Portfolio since May 2016.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

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SUMMARY PROSPECTUSMAY 1, 2017 Balanced Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is to realize as high a level of total return as is consistent with prudent investment risk,through income and capital appreciation.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.30%

Distribution and Service (12b-1) Fees None

Other Expenses 0.01%

Acquired Fund Fees and Expenses 0.46%

Total Annual Portfolio Operating Expenses(1) 0.77%

Fee Waiver(2) (0.25)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1), (2) 0.52%

(1) Includes fees and expenses incurred indirectly by the Portfolio as aresult of investments in other investment companies (Acquired FundFees and Expenses). The operating expenses of the Portfolio reflectedin the Portfolio’s most recent annual report and Financial Highlightsdo not include Acquired Fund Fees and Expenses.(2) The Portfolio’s investment adviser has entered into a writtenagreement to waive a portion of its management fee. This fee waiveragreement may be terminated by the adviser at any time afterApril 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$54 $222 $405 $936

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 23.64% of the average value of its portfolio.

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PRINCIPAL INVESTMENT STRATEGIESInvesting in the stock, bond and money market sectors, the Portfolio attempts to capitalize on the variation in return potentialproduced by the interaction of changing financial markets and economic conditions while maintaining a balance over timebetween investment opportunities and their associated potential risks by following a flexible policy of allocating assets across thethree market sectors.

The Portfolio is tactically and strategically managed to capitalize on changing financial markets and economic conditionsfollowing a flexible policy for allocating assets according to the following benchmarks:

Equity Exposure Fixed Income or Debt Exposure Cash Equivalents

35 – 55% 40 – 60% 0 – 20%

These benchmarks are not minimum and maximum limits and the adviser, in pursuit of total return, may invest a greater or lesserpercentage in any component.

The Portfolio operates primarily as a “fund of funds” to gain the Portfolio’s equity and fixed income exposure by investing in oneor more of the equity and international portfolios, and one or more of the fixed income portfolios, of Northwestern Mutual SeriesFund, Inc. (each, an “Underlying Portfolio”). The adviser allocates the Portfolio’s assets among the Underlying Portfolios based onthe adviser’s economic and market outlook and the investment objectives and strategies of the Underlying Portfolios. With respectto the equity and international Underlying portfolios, the adviser considers their investment focus on small, mid or large marketcapitalizations, domestic or foreign investments, whether the Underlying Portfolio is diversified or non-diversified and whether itemploys a “growth” or “value” style of investing, among other characteristics. With respect to fixed income Underlying Portfolios,the adviser considers their focus on investment grade or non-investment grade securities, domestic or foreign investments, whetherthe issuer is a government or government agency, the duration (that is, a measure of the sensitivity of a portfolio’s fixed incomesecurities to changes in interest rates) and maturity of the Underlying Portfolio, and other characteristics. The adviser regularlyreviews and adjusts the allocation among the Underlying Portfolios to favor investments in those Underlying Portfolios that theadviser believes provide the most favorable position for achieving the Portfolio’s investment objective.

In connection with the allocation process, the Portfolio may invest more than 25% of its assets in one Underlying Portfolio,except that no more than 20% of the Portfolio’s assets will be allocated to the High Yield Bond Portfolio. The Portfolio mayinvest up to 25% of its assets in international Underlying Portfolios. The Portfolio may have exposure to high yield debt securities(so called “junk bonds”) and foreign investments in excess of these limits from time to time through its investment in otherUnderlying Portfolios.

Through its investments in the equity and international Underlying Portfolios, the Portfolio may be exposed to a wide range ofequity securities and other instruments, including small, mid and large cap U.S. and non-U.S. stocks. Equity securities couldinclude common and preferred stocks, securities convertible into stocks and depositary receipts for those securities. Through itsinvestments in the fixed income Underlying Portfolios, the Portfolio may be exposed to a wide range of fixed income securitieswith varying durations and maturities, including investment grade and non-investment grade debt securities, debt of corporate andgovernment issuers, inflation-indexed debt securities, and other fixed income instruments. An Underlying Portfolio may invest alarge percentage of its assets in a single issuer, security, market or sector (or a limited group thereof) or in the case of aninternational Underlying Portfolio, may invest in emerging markets, a small number of countries or a particular geographicregion. An Underlying Portfolio may also use certain derivative instruments including futures, forwards, options and swaps tomeet its investment objective and for cash management purposes.

The cash equivalent portion of the Portfolio may include, but is not limited to, investments in debt securities issued or guaranteedby the U.S. government or its agencies or instrumentalities, including mortgage- and asset-backed securities, as well ascommercial paper, banker’s acceptances, certificates of deposit and time deposits.

When the adviser deems it to be more efficient or advantageous in managing the Portfolio, the adviser may utilize futures andexchange-traded funds (“ETFs”) and, to a lesser extent, options, forwards and swap agreements (including the purchase and sale oftotal return equity swaps and credit default swaps) to gain additional exposure to certain markets, sectors or regions as alternativesto investments in Underlying Portfolios, to adjust the Portfolio for the adviser’s view on style or term structure and duration, toprovide increased flexibility in asset allocation, to earn income and to otherwise seek to enhance returns or to hedge foreigncurrency exposure. The ETFs in which the Portfolio may invest are not portfolios of Northwestern Mutual Series Fund, Inc.

The Portfolio is designed primarily for investors who want their investment allocated across major asset classes while pursuingthe growth potential of equities, but who also want the income potential of bonds. The investor should be willing to acceptfluctuation in share prices that are typical for a portfolio that holds equity investments.

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PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The Portfolio bears all of the risks associated with the investment strategiesused by the Underlying Portfolios. Except as otherwise stated, references in this section to the “Portfolio” may relate to thePortfolio, one or more Underlying Portfolios, or both. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform other mutual funds or lose money.

• Affiliated Portfolio Risk – In managing the Portfolio, the adviser has the authority to select, and allocate among, UnderlyingPortfolios. The adviser may be subject to potential conflicts of interest in selecting Underlying Portfolios because the fees paidto it by some Underlying Portfolios are higher than the fees paid by other Underlying Portfolios. Moreover, a situation couldoccur where proper action for the Portfolio could be adverse to the interest of the Underlying Portfolios or vice versa.

• Asset Allocation Risk – This Portfolio allocates its investments between stock, bond and money market sectors, certainsecurities and among Underlying Portfolios, based upon judgments made by the adviser. The Portfolio could miss attractiveinvestment opportunities by underweighting markets or sectors where there are significant returns, and could lose value byoverweighting markets where there are significant declines, or may not correctly predict the times to shift assets from one typeof investment to another.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security held directly or through anUnderlying Portfolio is unwilling or unable to meet its financial obligations.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that changes in the value of thederivatives may not correlate as intended with the underlying asset, rate or index, the risk of adverse price movements in themarket, the risk of missed opportunities in other investments and the risk that the counterparty to a derivatives transaction failsto make the required payment or otherwise comply with the terms of the contract. Certain derivatives involve leverage, whichcould cause the Portfolio to lose more than the principal amount invested. Other risks include management, interest rate andliquidity risks.

• Equity Securities Risk – The value of equity securities held through the Underlying Portfolios, such as common and preferredstocks, could decline if the financial condition of the companies an Underlying Portfolio is invested in declines or if overallmarket and economic conditions deteriorate. Equity securities generally have greater price volatility than fixed incomesecurities. Investments in rights and warrants may be more volatile than the underlying investments in stocks.

• Exchange Traded Funds Risk – Investing in exchange traded funds (ETFs) may expose the Portfolio to greater risk of lossand price fluctuation than investing directly in a comparable portfolio of stocks comprising the index due to lack of liquidity,the additional expenses incurred as a shareholder in another investment company, and tracking error. ETFs are also subject tothe risk that their market prices may trade at a premium or discount to their net asset value, which means the Portfolio willoverpay for an ETF’s assets if it is trading at a premium and will get less than the value of the ETF’s assets when selling if it istrading at a discount. An active market for an ETF may not be developed or maintained. Trading of an ETF’s shares may behalted by the exchange, in which case the Portfolio would be unable to sell its ETF shares unless and until trading is resumed.

• Foreign Investing Risk – Exposure to investments in foreign securities, including through Underlying Portfolios and ETFs,may subject the Portfolio to more rapid and extreme changes in value or more losses than a fund that invests exclusively inU.S. securities. This risk is due to potentially smaller markets, differing reporting, accounting and auditing standards, andnationalization, expropriation or confiscatory taxation, currency blockage, political and economic conditions, or diplomaticdevelopments. Foreign securities may be adversely affected by decreases in foreign currency values relative to the U.S. dollarand may be less liquid, more volatile, and harder to value than U.S. securities. Exposure to investments in emerging marketsheighten these risks due to a lack of established legal, political, business and social frameworks to support securities markets.

• Fund of Funds Investing Risk – The Portfolio’s investment performance is significantly impacted by the investmentperformance of the Underlying Portfolios it holds. The ability of the Portfolio to meet its investment objective is related to theability of the Underlying Portfolios to meet their respective investment objectives as well as the adviser’s allocation decisionswith respect to the Underlying Portfolios. Each of the Underlying Portfolios has its own investment risks, and the Portfolio isindirectly exposed to all the risks of the Underlying Portfolios in direct proportion to the amount of assets the Portfolioallocates to each Underlying Portfolio. To the extent that the Portfolio invests a significant portion of its assets in a singleUnderlying Portfolio, it will be particularly sensitive to the risks associated with that Underlying Portfolio. Changes in thevalue of that Underlying Portfolio may have a significant effect on the Portfolio’s net asset value. The Portfolio will bear a prorata share of the Underlying Portfolios’ expenses.

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• Geographic Concentration Risk – The Portfolio’s performance could be more volatile than that of a more geographicallydiversified fund and could be significantly impacted as a result of the Portfolio investing a relatively large percentage of itsassets in issuers located in a single country, a small number of countries, or a particular geographic region. Also, the Portfolio’sperformance may be more closely tied to the market, currency, economic, political, or regulatory conditions in those countriesor that region. Similarly, the extent to which an Underlying Portfolio invests a significant portion of its assets in a singlecountry, a small number of countries or a particular geographic region, may also adversely impact the Portfolio, depending onthe Portfolio’s level of investment in that Underlying Portfolio.

• High Yield Debt Risk – High yield debt securities (so called “junk bonds”) to which the Portfolio has exposure have greaterinterest rate and credit risk, may be more difficult to sell or sell at a reasonable price, and have greater risk of loss than higherrated securities.

• Interest Rate Risk – Prices of fixed income instruments generally rise and fall in response to changes in market interest rates.In a rising interest rate environment, the value of the fixed income investments to which the Portfolio has exposure is likely todecline. Currently, interest rates are near unprecedented historically low levels. A significant rise in interest rates over a shortperiod of time could cause significant losses in the market value of the Portfolio’s fixed income instruments. Durationmeasures the price sensitivity of a fixed income instrument to changes in interest rates. The Portfolio’s exposure to fixedincome instruments and Underlying Portfolios with a longer average portfolio duration will be more sensitive to changes ininterest rates than those with a shorter average duration.

• Investment Style Risk – The Portfolio is subject to risks associated with an Underlying Portfolio’s particular style ofinvesting, such as growth or value or a combination of both, and may underperform with respect to its allocation to theUnderlying Portfolio when the market does not favor that particular investment style. Different investment styles tend to shiftin and out of favor, depending on market conditions and investor sentiment.

• Large Cap Company Risk – Exposure to investments in large cap stocks could cause the Portfolio to underperform inmarkets favoring faster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow andmay not have the same growth potential as stocks with smaller capitalizations.

• Large Transaction Risk – The Underlying Portfolios are used as investments for certain fund of funds, including thePortfolio, and may have a large percentage of their shares owned by such funds. Large redemption activity by the Portfolio oranother fund of funds could result in the Underlying Portfolio being forced to sell portfolio securities at a loss to meetredemptions. The adviser may coordinate directly with the portfolio managers of the Underlying Portfolios to attempt to ensurethat transactions are accommodated efficiently, including possibly implementing trades over a period of days rather than all atonce. These practices may temporarily affect the adviser’s ability to fully implement the Portfolio’s investment strategies.

• Liquidity Risk – Particular investments, such as small and micro cap stocks, fixed income securities, foreign securities, inparticular emerging markets securities, and derivatives to which the Portfolio has exposure, can be difficult to purchase or sellat an advantageous time or price, if at all. These risks may be magnified during periods of economic turmoil or in an extendedeconomic downturn.

• Market Risk – The risk that the market price of securities owned by the Portfolio or an Underlying Portfolio in which thePortfolio invests may go up or down, sometimes rapidly or unpredictably, due to factors affecting securities markets generallyor particular industries.

• Micro Cap Company Risk – Exposure to investments in micro cap stocks may cause the Portfolio to experience more rapidand extreme changes in value than a fund that invests solely in small, mid and large cap stocks due to a more limited trackrecord, narrower product markets, more limited resources, higher risk of failure, and less liquid trading markets.

• Mortgage- and Asset-Backed Securities Risk – The risks of investing in mortgage-related and other asset-backed securities,including interest rate risk, credit risk, liquidity risk, extension risk and prepayment risk.

• Sector Concentration Risk – To the extent the Portfolio invests in Underlying Portfolios with a relatively high percentage ofassets in a particular sector, it will have greater exposure to the risks associated with that sector, including the risk that thesecurities of companies within the sector will underperform due to adverse economic conditions, regulatory or legislativechanges or increased competition affecting the sector. To the extent the Portfolio invests in Underlying Portfolios that areunderweight other sectors, the Portfolio risks missing out on advances in those sectors.

• Small and Mid Cap Company Risk – Exposure to investments in small and mid cap stocks may cause greater risk of loss andprice fluctuation than investing in stocks of larger cap companies due to a more limited track record, narrower product markets,more limited resources and less liquid trading markets. These stocks may be more volatile and more difficult to buy and sellthan stocks with larger capitalizations.

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• U.S. Government Securities Risk – Not all obligations of the U.S. government, its agencies and instrumentalities are backedby the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency orinstrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or itsagencies or instrumentalities of a security held by the Portfolio does not apply to the market value of such security or to sharesof the Portfolio itself.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance for both equity and fixedincome securities, the returns of a composite of indices of securities with characteristics similar to those the Portfolio typicallyholds, and the average returns of a peer group of portfolios underlying variable insurance products with similar characteristics tothose of the Portfolio. Returns are based on past results and are not an indication of future performance. Neither the bar chart northe table reflects the fees and expenses separately charged by the variable annuity contract or variable life insurance policyseparate account that invests in the Portfolio and returns would be lower if those fees and expenses were reflected.

2016

2015

-30%

-20%

-10%

0%

10%

20%

30%

2013

2014

2007

2008

2009

2010

2011

2012

6.58%6.15%

-22.72%

-0.12%

21.43%

11.96%

2.11%

9.69%12.08%

5.56%

Best Qtr: 3rd – ‘09 11.15% Worst Qtr: 4th – ‘08 -12.20%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Balanced Portfolio6.58% 6.68% 4.64%

S&P 500® Index(reflects no deduction for fees, expenses or taxes)11.96% 14.66% 6.95%

Bloomberg Barclays® U.S. Aggregate Index(reflects no deduction for fees, expenses or taxes)2.65% 2.23% 4.34%

Balanced Portfolio Blended Composite: Russell 1000® Index (26%),Russell MidCap Index (9%), Russell 2000 Index (3%), MSCI®EAFE Index (9%), MSCI® Emerging Markets Index (2%),Bloomberg Barclays® U.S. Aggregate Bond Index (41%),Bloomberg Barclays® U.S. Corporate High Yield 2% IssuerCapped Bond Index (6%) and BofA Merrill Lynch® US 3-MonthTreasury Bill Index (4%).

(reflects no deduction for fees, expenses or taxes)7.74% 7.84% 5.68%

Lipper® Variable Insurance Products (VIP) Mixed-Asset TargetAllocation Moderate Funds Average

(reflects deductions for fees and expenses)6.14% 7.37% 4.76%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Portfolio Manager: Daniel J. Meehan manages the allocation of the Portfolio’s assets among the asset classes and among theUnderlying Portfolios. He is a Director of MSA, joined MSA in 2004 and has managed the Portfolio since 2013.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

NMSF–89 Northwestern Mutual Series Fund, Inc.

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SUMMARY PROSPECTUSMAY 1, 2017 Asset Allocation Portfolio

Before you invest, you may want to review the Portfolio’s prospectus, which contains more information about the Portfolioand its risks. You can find the Portfolio’s prospectus and other information about the Portfolio online atwww.nmseriesfund.com. You can also get this information at no cost by calling 1-888-455-2232 or by sending an e-mailrequest to [email protected]. The current prospectus and statement of additional information, eachdated May 1, 2017, along with the Portfolio’s most recent annual report dated December 31, 2016, are incorporated byreference into this Summary Prospectus. The Portfolio’s statement of additional information and annual report may beobtained, free of charge, in the same manner as the prospectus.

INVESTMENT OBJECTIVEThe investment objective of the Portfolio is to realize as high a level of total return as is consistent with reasonable investment risk.

FEES AND EXPENSES OF THE PORTFOLIOThe table below describes the fees and expenses that you may pay when you buy and hold interests in a separate account thatinvests in shares of the Portfolio as a result of your purchase of a variable annuity contract or variable life insurance policy. Thefees and expenses shown in the table and Example do not reflect fees and expenses separately charged by variable annuitycontracts or variable life insurance policies. If the fees and expenses separately charged by variable annuity contracts and variablelife insurance policies were included, the fees and expenses shown in the table and the Example would be higher.

Shareholder Fees(fees paid directly from your investment) N/A

Annual Portfolio Operating Expenses(expenses that you pay each year as a percentageof the value of your investment)

Management Fee 0.54%

Distribution and Service (12b-1) Fees None

Other Expenses 0.04%

Acquired Fund Fees and Expenses 0.52%

Total Annual Portfolio Operating Expenses(1) 1.10%

Fee Waiver(2) (0.49)%

Total Annual Portfolio Operating Expenses AfterFee Waiver(1), (2) 0.61%

(1) Includes fees and expenses incurred indirectly by thePortfolio as a result of investments in other investmentcompanies (Acquired Fund Fees and Expenses). The operatingexpenses of the Portfolio reflected in the Portfolio’s mostrecent annual report and Financial Highlights do not includeAcquired Fund Fees and Expenses.(2) The Portfolio’s investment adviser has entered into awritten agreement to waive a portion of its management fee.This fee waiver agreement may be terminated by the adviserat any time after April 30, 2018.

ExampleThis Example is intended to help you compare the cost ofinvesting in the Portfolio with the cost of investing in othermutual funds. The Example assumes that you invest $10,000in the Portfolio for the time periods indicated and then redeemall of your shares at the end of those periods. The Examplealso assumes that your investment has a 5% return each yearand that the Portfolio’s operating expenses remain the same.The Example reflects adjustments made to the Portfolio’soperating expenses due to the fee waiver agreement with theinvestment adviser for the first year only. Although youractual costs may be higher or lower, based on theseassumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$63 $302 $560 $1,298

Portfolio TurnoverThe Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Ahigher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in Annual PortfolioOperating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’sportfolio turnover rate was 25.59% of the average value of its portfolio.

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PRINCIPAL INVESTMENT STRATEGIESInvesting in the stock, bond and money market sectors, the Portfolio attempts to capitalize on the variation in return potentialproduced by the interaction of changing financial markets and economic conditions while maintaining a balance over timebetween investment opportunities and their associated potential risks by following a flexible policy of allocating assets across thethree market sectors.

The Portfolio is tactically and strategically managed to capitalize on changing financial markets and economic conditionsfollowing a flexible policy for allocating assets according to the following benchmarks:

Equity Exposure Fixed Income or Debt Exposure Cash Equivalents

55 – 75% 25 – 45% 0 – 15%

These benchmarks are not minimum and maximum limits and the adviser, in pursuit of total return, may invest a greater or lesserpercentage in any component.

The Portfolio operates primarily as a “fund of funds” to gain the Portfolio’s equity and fixed income exposure by investing in oneor more of the equity and international portfolios, and one or more of the fixed income portfolios, of Northwestern Mutual SeriesFund, Inc. (each, an “Underlying Portfolio”). The adviser allocates the Portfolio’s assets among the Underlying Portfolios based onthe adviser’s economic and market outlook and the investment objectives and strategies of the Underlying Portfolios. With respectto the equity and international Underlying Portfolios, the adviser considers their investment focus on small, mid or large marketcapitalizations, domestic or foreign investments, whether the Underlying Portfolio is diversified or non-diversified and whether itemploys a “growth” or “value” style of investing, among other characteristics. With respect to fixed income Underlying Portfolios,the adviser considers their focus on investment grade or non-investment grade securities, domestic or foreign investments, whetherthe issuer is a government or government agency, the duration (that is, a measure of the sensitivity of a portfolio’s fixed incomesecurities to changes in interest rates) and maturity of the Underlying Portfolio, and other characteristics. The adviser regularlyreviews and adjusts the allocation among the Underlying Portfolios to favor investments in those Underlying Portfolios that theadviser believes provide the most favorable position for achieving the Portfolio’s investment objective.

In connection with the allocation process, the Portfolio may invest more than 25% of its assets in one Underlying Portfolio,except that no more than 20% of the Portfolio’s assets will be allocated to the High Yield Bond Portfolio. The Portfolio mayinvest up to 30% of its assets in international Underlying Portfolios. The Portfolio may have exposure to high yield debt securities(so called “junk bonds”) and foreign investments in excess of these limits from time to time through its investments in otherUnderlying Portfolios.

Through its investments in the equity Underlying Portfolios, the Portfolio may be exposed to a wide range of equity securities andother instruments, including small, mid and large cap U.S. and non-U.S. stocks. Equity securities could include common andpreferred stocks, securities convertible into stocks and depositary receipts for those securities. Through its investments in thefixed income Underlying Portfolios, the Portfolio may be exposed to a wide range of fixed income securities with varyingdurations and maturities, including investment grade and non-investment grade debt securities, debt of corporate and governmentissuers, inflation-indexed debt securities, and other fixed income instruments. An Underlying Portfolio may invest a largepercentage of its assets in a single issuer, security, market or sector (or a limited group thereof) or in the case of an internationalUnderlying Portfolio, may invest in emerging markets, a small number of countries or a particular geographic region. AnUnderlying Portfolio may also use certain derivative instruments including futures, forwards, options and swaps to meet itsinvestment objective and for cash management purposes.

The cash equivalent portion of the Portfolio may include, but is not limited to, investments in debt securities issued or guaranteedby the U.S. government or its agencies or instrumentalities, including mortgage- and asset-backed securities, as well ascommercial paper, banker’s acceptance, certificates of deposit and time deposits.

When the adviser deems it to be more efficient or advantageous in managing the Portfolio, the adviser may utilize futures andexchange-traded funds (“ETFs”) and, to a lesser extent, options, forwards and swap agreements (including the purchase and sale oftotal return equity swaps and credit default swaps) to gain additional exposure to certain markets, sectors or regions as alternativesto investments in Underlying Portfolios, to adjust the Portfolio for the adviser’s view on style or term structure and duration, toprovide increased flexibility in asset allocation, to earn income and to otherwise seek to enhance returns or to hedge foreigncurrency exposure. The ETFs in which the Portfolio may invest are not portfolios of Northwestern Mutual Series Fund, Inc.

The Portfolio is designed primarily for investors who want their investment allocated across major asset classes while pursuingthe growth potential of equities with a smaller allocation to bonds. The investor should be willing to accept fluctuation in shareprices that are typical for a portfolio that holds equity investments.

NMSF–91 Northwestern Mutual Series Fund, Inc.

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PRINCIPAL RISKSPortfolio shares will rise and fall in value and there is a risk you could lose money by investing in the Portfolio. There can be noassurance that the Portfolio will achieve its objective. The Portfolio bears all of the risks associated with the investment strategiesused by the Underlying Portfolios. Except as otherwise stated, references in this section to the “Portfolio” may relate to thePortfolio, one or more Underlying Portfolios, or both. The main risks of investing in this Portfolio are identified below.

• Active Management Risk – The adviser’s investment strategies and techniques may not perform as expected which couldcause the Portfolio to underperform or lose money.

• Affiliated Portfolio Risk – In managing the Portfolio, the adviser has the authority to select, and allocate among, UnderlyingPortfolios. The adviser may be subject to potential conflicts of interest in selecting Underlying Portfolios because the fees paidto it by some Underlying Portfolios are higher than the fees paid by other Underlying Portfolios. Moreover, a situation couldoccur where proper action for the Portfolio could be adverse to the interest of the Underlying Portfolio or vice versa.

• Asset Allocation Risk – This Portfolio allocates its investments between stock, bond and money market sectors, certainsecurities, and among Underlying Portfolios, based upon judgments made by the adviser. The Portfolio could miss attractiveinvestment opportunities by underweighting markets or sectors where there are significant returns, and could lose value byoverweighting markets where there are significant declines, or may not correctly predict the times to shift assets from one typeof investment to another.

• Credit Risk – The Portfolio could lose money if the issuer or guarantor of a fixed income security held directly or through anUnderlying Portfolio is unwilling or unable to meet its financial obligations.

• Derivatives Risk – The value of a derivative generally depends upon, or is derived from, an underlying asset, reference rate orindex. The primary risks associated with the Portfolio’s use of derivatives are the risk that changes in the value of the derivativesmay not correlate as intended with the underlying asset, rate or index, the risk of adverse price movements in the market, the riskof missed opportunities in other investments and the risk that the counterparty to a derivatives transaction fails to make therequired payment or otherwise comply with the terms of the contract. Certain derivatives involve leverage, which could cause thePortfolio to lose more than the principal amount invested. Other risks include management, interest rate and liquidity risks.

• Equity Securities Risk – The value of equity securities held through the Underlying Portfolios, such as common and preferredstocks, could decline if the financial condition of the companies an Underlying Portfolio is invested in declines or if overallmarket and economic conditions deteriorate. Equity securities generally have greater price volatility than fixed incomesecurities. Investments in rights and warrants may be more volatile than the underlying investments in stocks.

• Exchange Traded Funds Risk – Investing in exchange traded funds (ETFs) may expose the Portfolio to greater risk of lossand price fluctuation than investing directly in a comparable portfolio of stocks comprising the index due to lack of liquidity,the additional expenses incurred as a shareholder in another investment company, and tracking error. ETFs are also subject tothe risk that their market prices may trade at a premium or discount to their net asset value, which means the Portfolio willoverpay for an ETF’s assets if it is trading at a premium and will get less than the value of the ETF’s assets when selling if it istrading at a discount. An active market for an ETF may not be developed or maintained. Trading of an ETF’s shares may behalted by the exchange, in which case the Portfolio would be unable to sell its ETF shares unless and until trading is resumed.

• Foreign Investing Risk – Exposure to investments in foreign securities, including through Underlying Portfolios and ETFs,may subject the Portfolio to more rapid and extreme changes in value or more losses than a fund that invests exclusively inU.S. securities. This risk is due to potentially smaller markets, differing reporting, accounting and auditing standards, andnationalization, expropriation or confiscatory taxation, currency blockage, political and economic conditions, or diplomaticdevelopments. Foreign securities may be adversely affected by decreases in foreign currency values relative to the U.S. dollarand may be less liquid, more volatile, and harder to value than U.S. securities. Exposure to investments in emerging marketsheighten these risks due to a lack of established legal, political, business and social frameworks to support securities markets.

• Fund of Funds Investing Risk – The Portfolio’s investment performance is significantly impacted by the investmentperformance of the Underlying Portfolios it holds. The ability of the Portfolio to meet its investment objective is related to theability of the Underlying Portfolios to meet their respective investment objectives as well as the adviser’s allocation decisionswith respect to the Underlying Portfolios. Each of the Underlying Portfolios has its own investment risks, and the Portfolio isindirectly exposed to all the risks of the Underlying Portfolios in direct proportion to the amount of assets the Portfolioallocates to each Underlying Portfolio. To the extent that the Portfolio invests a significant portion of its assets in a singleUnderlying Portfolio, it will be particularly sensitive to the risks associated with that Underlying Portfolio. Changes in thevalue of that Underlying Portfolio may have a significant effect on the Portfolio’s net asset value. The Portfolio will bear a prorata share of the Underlying Portfolios’ expenses.

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• Geographic Concentration Risk – The Portfolio’s performance could be more volatile than that of a more geographicallydiversified fund and could be significantly impacted as a result of the Portfolio investing a relatively large percentage of itsassets in issuers located in a single country, a small number of countries, or a particular geographic region. Also, the Portfolio’sperformance may be more closely tied to the market, currency, economic, political, or regulatory conditions in those countriesor that region. Similarly, the extent to which an Underlying Portfolio invests a significant portion of its assets in a singlecountry, a small number of countries or a particular geographic region, may also adversely impact the Portfolio, depending onthe Portfolio’s level of investment in that Underlying Portfolio.

• High Yield Debt Risk – High yield debt securities (so called “junk bonds”) to which the Portfolio has exposure have greaterinterest rate and credit risk, may be more difficult to sell or sell at a reasonable price, and have greater risk of loss than higherrated securities.

• Interest Rate Risk – Prices of fixed income instruments generally rise and fall in response to changes in market interest rates.In a rising interest rate environment, the value of the fixed income investments to which the Portfolio has exposure is likely todecline. Currently, interest rates are near unprecedented historically low levels. A significant rise in interest rates over a shortperiod of time could cause significant losses in the market value of the Portfolio’s fixed income instruments. Durationmeasures the price sensitivity of a fixed income instrument to changes in interest rates. The Portfolio’s exposure to fixedincome instruments and Underlying Portfolios with a longer average portfolio duration will be more sensitive to changes ininterest rates than those with a shorter average duration.

• Investment Style Risk – The Portfolio is subject to risks associated with an Underlying Portfolio’s particular style ofinvesting, such as growth or value or a combination of both, and may underperform with respect to its allocation to theUnderlying Portfolio when the market does not favor that particular investment style. Different investment styles tend to shiftin and out of favor, depending on market conditions and investor sentiment.

• Large Cap Company Risk – Exposure to investments in large cap stocks could cause the Portfolio to underperform inmarkets favoring faster growing companies. Large cap stocks tend to be more mature with fewer opportunities to grow andmay not have the same growth potential as stocks with smaller capitalizations.

• Large Transaction Risk – The Underlying Portfolios are used as investments for certain fund of funds, including thePortfolio, and may have a large percentage of their shares owned by such funds. Large redemption activity by the Portfolio oranother fund of funds could result in the Underlying Portfolio being forced to sell portfolio securities at a loss to meetredemptions. The adviser may coordinate directly with the portfolio managers of the Underlying Portfolios to attempt to ensurethat transactions are accommodated efficiently, including possibly implementing trades over a period of days rather than all atonce. These practices may temporarily affect the adviser’s ability to fully implement the Portfolio’s investment strategies.

• Liquidity Risk – Particular investments, such as small and micro cap stocks, fixed income securities, foreign securities, inparticular emerging markets securities, and derivatives to which the Portfolio has exposure, can be difficult to purchase or sellat an advantageous time or price, if at all. These risks may be magnified during periods of economic turmoil or in an extendedeconomic downturn.

• Market Risk – The risk that the market price of securities owned by the Portfolio or an Underlying Portfolio in which thePortfolio invests may go up or down, sometimes rapidly or unpredictably, due to factors affecting securities markets generallyor particular industries.

• Micro Cap Company Risk – Exposure to investments in micro cap stocks may cause the Portfolio to experience more rapidand extreme changes in value than a fund that invests solely in small, mid and large cap stocks due to a more limited trackrecord, narrower product markets, more limited resources, higher risk of failure, and less liquid trading markets.

• Mortgage- and Asset-Backed Securities Risk – The risks of investing in mortgage-related and other asset-backed securities,including interest rate risk, credit risk, liquidity risk, extension risk and prepayment risk.

• Sector Concentration Risk – To the extent the Portfolio invests in Underlying Portfolios with a relatively high percentage ofassets in a particular sector, it will have greater exposure to the risks associated with that sector, including the risk that thesecurities of companies within the sector will underperform due to adverse economic conditions, regulatory or legislativechanges or increased competition affecting the sector. To the extent the Portfolio invests in Underlying Portfolios that areunderweight other sectors, the Portfolio risks missing out on advances in those sectors.

• Small and Mid Cap Company Risk – Exposure to investments in small and mid cap stocks may cause greater risk of loss andprice fluctuation than investing in stocks of larger cap companies due to a more limited track record, narrower product markets,more limited resources and less liquid trading markets. These stocks may be more volatile and more difficult to buy and sellthan stocks with larger capitalizations.

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• U.S. Government Securities Risk – Not all obligations of the U.S. government, its agencies and instrumentalities are backedby the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency orinstrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or itsagencies or instrumentalities of a security held by the Portfolio does not apply to the market value of such security or to sharesof the Portfolio itself.

PERFORMANCEThe following bar chart illustrates the risks of investing in the Portfolio by showing how the performance of the Portfolio hasvaried from year to year. The table to the right of the bar chart shows the Portfolio’s average annual total return over certain timeperiods and compares the Portfolio’s returns with those of a broad measure of market performance for both equity and fixedincome securities, the returns of a composite of indices of securities with characteristics similar to those the Portfolio typicallyholds, and the average returns of a peer group of portfolios underlying variable insurance products with similar characteristics tothose of the Portfolio. Returns are based on past results and are not an indication of future performance. Neither the bar chart northe table reflects the fees and expenses separately charged by the variable annuity contract or variable life insurance policyseparate account that invests in the Portfolio and returns would be lower if those fees and expenses were reflected.

-40%

-30%

-20%

-10%

0%

10%

20%

40%

30%

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

7.79%9.40%

-30.13%

-0.43%

27.09%

13.01%

-0.08%

11.02%16.67%

5.15%

Best Qtr: 2nd – ‘09 13.51% Worst Qtr: 4th – ‘08 -16.40%

Average Annual Total Return(for periods ended December 31, 2016)

1 Yr 5 Yrs 10 Yrs

Asset Allocation Portfolio7.79% 7.89% 4.84%

S&P 500® Index(reflects no deduction for fees, expenses or taxes)11.96% 14.66% 6.95%

Bloomberg Barclays® U.S. Aggregate Index(reflects no deduction for fees, expenses or taxes)2.65% 2.23% 4.34%

Asset Allocation Blended Composite: Russell 1000® Index (33%),Russell MidCap Index (11%), Russell 2000 Index (5%), MSCI®EAFE Index (13%), MSCI® Emerging Markets Index (3%),Bloomberg Barclays® U.S. Aggregate Bond Index (24%),Bloomberg Barclays® U.S. Corporate High Yield 2% IssuerCapped Bond Index (8%) and BofA Merrill Lynch® US 3-MonthTreasury Bill Index (3%).

(reflects no deduction for fees, expenses or taxes)9.56% 9.49% 5.91%

Lipper® Variable Insurance Products (VIP) Mixed-Asset TargetAllocation Growth Funds Average

(reflects deductions for fees and expenses)6.93% 8.81% 5.21%

PORTFOLIO MANAGEMENTInvestment Adviser: Mason Street Advisors, LLC (MSA)Portfolio Manager: Daniel J. Meehan manages the allocation of the Portfolio’s assets among the asset classes and among theUnderlying Portfolios. He is a Director of MSA, joined MSA in 2004 and has managed the Portfolio since 2013.

TAX INFORMATIONShares of the Portfolio are offered only for funding variable annuity contracts and variable life insurance policies offered by TheNorthwestern Mutual Life Insurance Company through separate accounts. Insurance company separate accounts generally do notpay tax on dividends or capital gain distributions. Investors in variable annuity contracts and variable life insurance policiesshould refer to the prospectuses for the variable products for a discussion of the tax considerations that affect the insurancecompany and its separate accounts and the tax consequences to investors of owning such products.

COMPENSATION TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIESNeither the Portfolio nor any related companies pay compensation to broker-dealers or other financial intermediaries for the saleof Portfolio shares or related services. Investors in variable annuity contracts and variable life insurance policies should refer tothe prospectuses for the variable products for important information about compensation paid to financial intermediaries for salesof variable annuity contracts and variable life insurance policies.

Northwestern Mutual Series Fund, Inc. NMSF–94

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Fidelity® Variable Insurance Products

Initial Class, Service Class, and Service Class 2Mid Cap Portfolio

Summary ProspectusApril 30, 2017

Before you invest, you may want to review the fund’s prospectus, which contains more information about the fund and its risks. You can find the fund’s prospectus and other information about the fund (including the fund’s SAI) online at institutional.fidelity.com/vipfunddocuments. You can also get this information at no cost by calling 1-866-997-1254 or by sending an e-mail request to [email protected]. The fund’s prospectus and SAI dated April 30, 2017 are incorporated herein by reference.

245 Summer Street, Boston, MA 02210

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Fund Summary

Fund/Class:VIP Mid Cap Portfolio/Initial Class, Service Class, Service Class 2

Investment ObjectiveThe fund seeks long-term growth of capital.

Fee TableThe following table describes the fees and expenses that may be incurred, directly or indirectly, when you, as a variable product

owner, buy and hold interests in a separate account that invests in shares of the fund. The table does not include any fees or other expenses of any variable annuity or variable life insurance product; if it did, overall fees and expenses would be higher.

Fees(fees paid directly from your investment) Not Applicable

Annual Operating Expenses(expenses that you pay each year as a % of the value of your investment)

Initial ClassService Class

Service Class 2

Management fee 0.55% 0.55% 0.55%

Distribution and/or Service (12b-1) fees None 0.10% 0.25%

Other expenses 0.08% 0.08% 0.08%

Total annual operating expenses 0.63% 0.73% 0.88%

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let’s say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant

to suggest actual or expected fees and expenses or returns, all of which may vary. This example does not include any fees or other expenses of any variable annuity or variable life insurance product; if it did, overall expenses would be higher. For every $10,000 invested, here’s how much you, as a variable product owner, would pay in total expenses if all interests in a separate account that invests in shares of the fund were redeemed at the end of each time period indicated:

Initial Class Service Class Service Class 2

1 year $ 64 $ 75 $ 90

3 years $ 202 $ 233 $ 281

5 years $ 351 $ 406 $ 488

10 years $ 786 $ 906 $ 1,084

Portfolio TurnoverThe fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 30% of the average value of its portfolio.

Principal Investment Strategies• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of compa-nies with medium market capitalizations (which, for purposes of this fund, are those companies with market capitalizations similar

to companies in the Russell Midcap® Index or the S&P MidCap 400® Index).

• Potentially investing in companies with smaller or larger market capitalizations.

• Investing in domestic and foreign issuers.

• Investing in either “growth” stocks or “value” stocks or both.

• Using fundamental analysis of factors such as each issuer’s finan-cial condition and industry position, as well as market and economic conditions, to select investments.

Principal Investment Risks• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regula-tory, market, or economic developments. Different parts of the

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3 Summary Prospectus

market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform dif-ferently from the U.S. market.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can per-form differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

• Mid Cap Investing. The value of securities of medium size, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers.

You could lose money by investing in the fund.

PerformanceThe following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund’s shares from year to year and compares the performance of the fund’s shares to the perfor-mance of a securities market index over various periods of time. The index description appears in the Additional Index Information sec-tion of the prospectus. Returns for shares of the fund do not include the effect of any sales charges or other expenses of any variable annuity or variable life insurance product; if they did, returns for shares of the fund would be lower. Past performance is not an indica-tion of future performance.

Year-by-Year Returns

5040302010

0-10-20-30-40

2016201520142013201220112010200920082007

12.23%-1.39%6.29%36.23%14.83%-10.61%28.83%40.09%-39.44%15.63%

Calendar Years

Percentage (%)

During the periods shown in the chart for Initial Class: Returns Quarter endedHighest Quarter Return 19.29% June 30, 2009Lowest Quarter Return –23.63% December 31, 2008

Average Annual Returns

For the periods ended December 31, 2016Past 1

yearPast 5 years

Past 10 years

Initial Class 12.23% 12.97% 7.59%

Service Class 12.11% 12.86% 7.48%

Service Class 2 11.92% 12.69% 7.32%

S&P MidCap 400® Index (reflects no deduction for fees, expenses, or taxes) 20.74% 15.33% 9.16%

Investment AdviserFidelity Management & Research Company (FMR) (the Adviser) is the fund’s manager. FMR Co., Inc. (FMRC) and other investment advisers serve as sub-advisers for the fund.

Portfolio Manager(s)Tom Allen (portfolio manager) has managed the fund since June 2001.

Purchase and Sale of SharesOnly Permitted Accounts, including separate accounts of insur-ance companies and qualified funds of funds that have signed the appropriate agreements with the fund, if applicable, can buy or sell shares. Insurance companies offer variable annuity and variable life insurance products through separate accounts. A qualified fund of funds is an eligible insurance-dedicated mutual fund that invests in other mutual funds.

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Fund Summary – continued

Permitted Accounts - not variable product owners - are the share-holders of the fund. Variable product owners hold interests in separate accounts, including separate accounts that are sharehold-ers of qualified funds of funds. The terms of the offering of interests in separate accounts are included in the variable annuity or variable life insurance product prospectus.

The price to buy one share is its net asset value per share (NAV). Shares will be bought at the NAV next calculated after an order is received in proper form.

The price to sell one share is its NAV. Shares will be sold at the NAV next calculated after an order is received in proper form.

The fund is open for business each day the New York Stock Exchange (NYSE) is open.

The fund has no minimum investment requirement.

Tax InformationVariable product owners seeking to understand the tax conse-quences of their investment should consult with their tax advisers or the insurance company that issued their variable product, or refer to their variable annuity or variable life insurance product prospectus. Insurance company separate accounts generally do not pay tax on dividends or capital gain distributions from the fund.

Payments to Broker-Dealers and Other Financial IntermediariesThe fund, the Adviser, Fidelity Distributors Corporation (FDC), and/or their affiliates may pay intermediaries, which may include insur-ance companies and their affiliated broker-dealers and service-pro-viders (who may be affiliated with the Adviser or FDC), for the sale of fund shares and related services. These payments may create a conflict of interest by influencing your intermediary and your invest-ment professional to recommend the fund over another investment. Ask your investment professional or visit your intermediary’s web site for more information.

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FDC is a member of the Securities Investor Protection Corporation (SIPC). You may obtain information about SIPC, including the SIPC brochure, by visiting www.sipc.org or calling SIPC at 202-371-8300.

Fidelity and Fidelity Investments & Pyramid Design are registered service marks of FMR LLC. © 2017 FMR LLC. All rights reserved.

Any third-party marks that may appear above are the marks of their respective owners.

The term “VIP” as used in this document refers to Fidelity® Variable Insurance Products.

1.907844.108 VMC-SUM-0417

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Fidelity® Variable Insurance Products

Initial Class, Service Class, and Service Class 2Contrafund® Portfolio

Summary ProspectusApril 30, 2017

As Revised November 17, 2017

Before you invest, you may want to review the fund’s prospectus, which contains more information about the fund and its risks. You can find the fund’s prospectus and other information about the fund (including the fund’s SAI) online at institutional.fidelity.com/vipfunddocuments. You can also get this information at no cost by calling 1-866-997-1254 or by sending an e-mail request to [email protected]. The fund’s prospectus dated April 30, 2017, as supplemented on November 17, 2017, and SAI dated April 30, 2017, as supplemented on October 23, 2017, are incorporated herein by reference.

245 Summer Street, Boston, MA 02210

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2Summary Prospectus

Fund Summary

Fund/Class:VIP ContrafundSM Portfolio/Initial Class, Service Class, Service Class 2

Investment ObjectiveThe fund seeks long-term capital appreciation.

Fee TableThe following table describes the fees and expenses that may be incurred, directly or indirectly, when you, as a variable product

owner, buy and hold interests in a separate account that invests in shares of the fund. The table does not include any fees or other expenses of any variable annuity or variable life insurance product; if it did, overall fees and expenses would be higher.

Fees(fees paid directly from your investment) Not Applicable

Annual Operating Expenses(expenses that you pay each year as a % of the value of your investment)

Initial ClassService Class

Service Class 2

Management fee 0.55% 0.55% 0.55%

Distribution and/or Service (12b-1) fees None 0.10% 0.25%

Other expenses 0.08% 0.08% 0.08%

Total annual operating expenses 0.63% 0.73% 0.88%

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let’s say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant

to suggest actual or expected fees and expenses or returns, all of which may vary. This example does not include any fees or other expenses of any variable annuity or variable life insurance product; if it did, overall expenses would be higher. For every $10,000 invested, here’s how much you, as a variable product owner, would pay in total expenses if all interests in a separate account that invests in shares of the fund were redeemed at the end of each time period indicated:

Initial Class Service Class Service Class 2

1 year $ 64 $ 75 $ 90

3 years $ 202 $ 233 $ 281

5 years $ 351 $ 406 $ 488

10 years $ 786 $ 906 $ 1,084

Portfolio TurnoverThe fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 62% of the average value of its portfolio.

Principal Investment Strategies• Normally investing primarily in common stocks.

• Investing in securities of companies whose value FidelityManagement & Research Company (FMR) believes is not fully recognized by the public.

• Investing in domestic and foreign issuers.

• Allocating the fund’s assets across different market sectors (atpresent, consumer discretionary, consumer staples, energy, finan-cials, health care, industrials, information technology, materials, real estate, telecom services, and utilities), using different Fidelity managers.

• Investing in either “growth” stocks or “value” stocks or both.

• Using fundamental analysis of factors such as each issuer’s finan-cial condition and industry position, as well as market and economic conditions, to select investments.

Principal Investment Risks• Stock Market Volatility. Stock markets are volatile and candecline significantly in response to adverse issuer, political, regula-tory, market, or economic developments. Different parts of the

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3 Summary Prospectus

market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile thanthe U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform dif-ferently from the U.S. market.

• Issuer-Specific Changes. The value of an individual securityor particular type of security can be more volatile than, and can perform differently from, the market as a whole.

You could lose money by investing in the fund.

PerformanceThe following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund’s shares from year to year and compares the performance of the fund’s shares to the perfor-mance of a securities market index over various periods of time. The index description appears in the Additional Index Information sec-tion of the prospectus. Returns for shares of the fund do not include the effect of any sales charges or other expenses of any variable annuity or variable life insurance product; if they did, returns for shares of the fund would be lower. Past performance is not an indica-tion of future performance.

Year-by-Year Returns

40302010

0-10-20-30-40-50

2016201520142013201220112010200920082007

8.04%0.64%11.94%31.29%16.42%-2.53%17.22%35.71%-42.51%17.59%

Calendar Years

Percentage (%)

During the periods shown in the chart for Initial Class: Returns Quarter endedHighest Quarter Return 18.85% June 30, 2009Lowest Quarter Return –23.07% December 31, 2008

Average Annual Returns

For the periods ended December 31, 2016Past 1

yearPast 5 years

Past 10 years

Initial Class 8.04% 13.22% 6.91%

Service Class 7.91% 13.10% 6.80%

Service Class 2 7.76% 12.93% 6.64%

S&P 500® Index (reflects no deduction for fees, expenses, or taxes) 11.96% 14.66% 6.95%

Investment AdviserFMR (the Adviser) is the fund’s manager. FMR Co., Inc. (FMRC) and other investment advisers serve as sub-advisers for the fund.

Portfolio Manager(s)The fund is managed by members of FMR’s Stock Selector Large Cap Group.

Robert Stansky (co-manager), Steven Kaye (co-manager), Robert Lee (co-manager), Douglas Simmons (co-manager), and Pierre Sorel (co-manager) have managed the fund since October 2007.

Jonathan Kasen (co-manager) has managed the fund since July 2013.

Brian Lempel (co-manager) has managed the fund since April 2013.

John Mirshekari (co-manager) has managed the fund since October 2016.

Chip Perrone (co-manager) has managed the fund since August 2017.

Richard Malnight (co-manager) has managed the fund since November 2017.

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4Summary Prospectus

Fund Summary – continued

Purchase and Sale of SharesOnly Permitted Accounts, including separate accounts of insur-ance companies and qualified funds of funds that have signed the appropriate agreements with the fund, if applicable, can buy or sell shares. Insurance companies offer variable annuity and variable life insurance products through separate accounts. A qualified fund of funds is an eligible insurance-dedicated mutual fund that invests in other mutual funds.

Permitted Accounts - not variable product owners - are the share-holders of the fund. Variable product owners hold interests in separate accounts, including separate accounts that are sharehold-ers of qualified funds of funds. The terms of the offering of interests in separate accounts are included in the variable annuity or variable life insurance product prospectus.

The price to buy one share is its net asset value per share (NAV). Shares will be bought at the NAV next calculated after an order is received in proper form.

The price to sell one share is its NAV. Shares will be sold at the NAV next calculated after an order is received in proper form.

The fund is open for business each day the New York Stock Exchange (NYSE) is open.

The fund has no minimum investment requirement.

Tax InformationVariable product owners seeking to understand the tax conse-quences of their investment should consult with their tax advisers or the insurance company that issued their variable product, or refer to their variable annuity or variable life insurance product prospectus. Insurance company separate accounts generally do not pay tax on dividends or capital gain distributions from the fund.

Payments to Broker-Dealers and Other Financial IntermediariesThe fund, the Adviser, Fidelity Distributors Corporation (FDC), and/or their affiliates may pay intermediaries, which may include insur-ance companies and their affiliated broker-dealers and service-pro-viders (who may be affiliated with the Adviser or FDC), for the sale of fund shares and related services. These payments may create a conflict of interest by influencing your intermediary and your invest-ment professional to recommend the fund over another investment. Ask your investment professional or visit your intermediary’s web site for more information.

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FDC is a member of the Securities Investor Protection Corporation (SIPC). You may obtain information about SIPC, including the SIPC brochure, by visiting www.sipc.org or calling SIPC at 202-371-8300.

Fidelity, Contrafund, and Fidelity Investments & Pyramid Design are registered service marks of FMR LLC. © 2017 FMR LLC. All rights reserved.

VIP Contrafund is a service mark of FMR LLC.

Any third-party marks that may appear above are the marks of their respective owners.

The term “VIP” as used in this document refers to Fidelity® Variable Insurance Products.

1.907822.116 VCON-SUM-0417-02

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May 1, 2017

SOCIALLY RESPONSIVE PORTFOLIO

SUMMARY PROSPECTUSClass I

The Fund is offered to certain life insurance companies to serve as an investment vehicle for premiums paid under their variable annuity and variable life insurance contracts(each, a “variable contract”) and to certain qualified pension and other retirement plans (each, a “qualified plan”). Before you invest, you may want to review the Fund’sprospectus, which contains more information about the Fund and its risks. You can find the Fund’s prospectus and other information about the Fund (including the Fund’sSAI) online at http://www.nb.com/amtportfolios/i. You can also get this information at no cost by calling 800-877-9700 or by sending an e-mail request to [email protected] can also get this information from your investment provider or any investment provider authorized to sell the Fund’s shares. The Fund’s prospectus and SAI, each datedMay 1, 2017 (as each may be amended or supplemented), are incorporated herein by reference.

GOALThe Fund seeks long-term growth of capital by investing primarily in securities of companies that meet the Fund’s financialcriteria and social policy.

FEES AND EXPENSESThese tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund. These tables do not reflectany fees and expenses charged by your insurance company under your variable contract or by your qualified plan. If the tables didreflect such fees and expenses, the overall expenses would be higher than those shown. Please refer to the prospectus for yourvariable contract or your qualified plan documentation for information on their separate fees and expenses.

Shareholder Fees (fees paid directly from your investment) None

Annual Fund Operating Expenses (expenses that you pay each year as a % of the value of your investment)

Management fees 0.84

Distribution and/or shareholder service (12b-1) fees None

Other expenses 0.16

Total annual operating expenses 1.00

Expense ExampleThe expense example can help you compare costs among mutual funds. The example assumes that you invested $10,000 for theperiods shown, that you redeemed all of your shares at the end of those periods, that the Fund earned a hypothetical 5% totalreturn each year, and that the Fund’s expenses were those in the table. Actual performance and expenses may be higher or lower.

1 Year 3 Years 5 Years 10 Years

Expenses $102 $318 $552 $1,225

Portfolio TurnoverThe Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higherportfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual operating expenses orin the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 31% ofthe average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIESTo pursue its goal, the Fund invests primarily in common stocks of mid- to large-capitalization companies that meet the Fund’ssocial policy.

The Fund seeks to reduce risk by investing across many different industries.

The Portfolio Managers employ a research driven and valuation sensitive approach to stock selection, with a long term perspective.They look for solid balance sheets, strong management teams with a track record of success, good cash flow and the prospect forabove-average earnings growth. They seek to purchase the stock of businesses that they believe to be well positioned and

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undervalued by the market. Among companies that meet these criteria, the Portfolio Managers look for those that show leadershipin environmental concerns, and progressive workplace practices including diversity and community relations.

In addition, the Portfolio Managers typically look at a company’s record in public health and the nature of its products. ThePortfolio Managers judge firms on their corporate citizenship overall, considering their accomplishments as well as their goals.While these judgments are inevitably subjective, the Fund endeavors to avoid companies that derive revenue from gambling or theproduction of alcohol, tobacco, weapons, or nuclear power. The Fund also does not invest in any company that derives its totalrevenue primarily from non-consumer sales to the military.

Please see the Statement of Additional Information for a detailed description of the Fund’s social investing policies.

Although the Fund invests primarily in domestic stocks, it may also invest in stocks of foreign companies.

The Portfolio Managers follow a disciplined selling strategy and may sell a stock when it reaches a target price, if a company’sbusiness fails to perform as expected, or when other opportunities appear more attractive.

The Fund may change its goal without shareholder approval, although it does not currently intend to do so. As a sociallyresponsive fund, the Fund is required by the federal securities laws to have a policy, which it cannot change without providinginvestors at least 60 days’ written notice, of investing at least 80% of its net assets in equity securities selected in accordance withits social policy. The 80% test is applied at the time the Fund invests; later percentage changes caused by a change in Fund assets,market values or company circumstances will not require the Fund to dispose of a holding. In practice, the Portfolio Managersintend to hold only securities selected in accordance with the Fund’s social investing policies.

Valuation Sensitive Investing. In addition to employing traditional value criteria – that is, looking for value among companieswhose stock prices are below their historical average, based on earnings, cash flow, or other financial measures – the PortfolioManagers may buy a company’s shares if they look more fully priced based on Wall Street consensus estimates of earnings, but stillinexpensive relative to the Portfolio Managers’ estimates. The Portfolio Managers look for these companies to rise in price as theyoutperform Wall Street’s expectations, because they believe some aspects of the business have not been fully appreciated orappropriately priced by other investors.

PRINCIPAL INVESTMENT RISKSMost of the Fund’s performance depends on what happens in the stock market. The market’s behavior can be difficult to predict,particularly in the short term. There can be no guarantee that the Fund will achieve its goal. The Fund may take temporarydefensive and cash management positions; in such a case, it will not be pursuing its principal investment strategies.

The Fund is a mutual fund, not a bank deposit, and is not guaranteed or insured by the Federal Deposit Insurance Corporation orany other government agency. The value of your investment may fall, sometimes sharply, and you could lose money by investingin the Fund.

The following risks, which are described in alphabetical order and not in order of importance or potential exposure, cansignificantly affect the Fund’s performance:

Currency Risk. Changes in currency exchange rates could adversely impact investment gains or add to investment losses.Currency exchange rates can be affected unpredictably by intervention, or failure to intervene, by U.S. or foreign governments orcentral banks or by currency controls or political developments in the U.S. or abroad.

Foreign Risk. Foreign securities involve risks in addition to those associated with comparable U.S. securities. Additional risksinclude exposure to less developed or less efficient trading markets; social, political, diplomatic or economic instability;fluctuations in foreign currencies or currency redenomination; potential for default on sovereign debt; nationalization orexpropriation of assets; settlement, custodial or other operational risks; higher transaction costs; confiscatory withholding or othertaxes; and less stringent auditing, corporate disclosure, governance and legal standards. As a result, foreign securities may fluctuatemore widely in price, and may also be less liquid, than comparable U.S. securities. World markets, or those in a particular region,may all react in similar fashion to important economic or political developments. In addition, foreign markets may performdifferently than the U.S. market. The effect of economic instability on specific foreign markets or issuers may be difficult topredict or evaluate.

Securities of issuers traded on exchanges may be suspended, either by the issuers themselves, by an exchange or by governmentalauthorities. Trading suspensions may be applied from time to time to the securities of individual issuers for reasons specific to thatissuer, or may be applied broadly by exchanges or governmental authorities in response to market events. In the event that the

SOCIALLY RESPONSIVE PORTFOLIO May 1, 2017

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Fund holds material positions in such suspended securities, the Fund’s ability to liquidate its positions or provide liquidity toinvestors may be compromised and the Fund could incur significant losses.

Issuer-Specific Risk. An individual security may be more volatile, and may perform differently, than the market as a whole.

The Fund’s portfolio may contain fewer securities than the portfolios of other mutual funds, which may increase the risk that thevalue of the Fund could go down because of the poor performance of one or a few investments.

Market Volatility Risk. Markets may be volatile and values of individual securities and other investments, including those of aparticular type, may decline significantly in response to adverse issuer, political, regulatory, market, economic or otherdevelopments that may cause broad changes in market value, public perceptions concerning these developments, and adverseinvestor sentiment. If the Fund sells a portfolio position before it reaches its market peak, it may miss out on opportunities forbetter performance.

Mid- and Large-Cap Companies Risk. At times, mid- and large-cap companies may be out of favor with investors. Compared tosmaller companies, large-cap companies may be less responsive to changes and opportunities. Compared to larger companies, mid-cap companies may depend on a more limited management group, may have a shorter history of operations, and may have limitedproduct lines, markets or financial resources. The securities of mid-cap companies are often more volatile and less liquid than thesecurities of larger companies and may be more affected than other types of securities by the underperformance of a sector orduring market downturns.

Operational Risk. The Fund and its service providers, and your ability to transact with the Fund, may be negatively impacteddue to operational risks arising from, among other problems, human errors, systems and technology disruptions or failures, orcybersecurity incidents. It is not possible for the Manager or the other Fund service providers to identify all of the operational risksthat may affect the Fund or to develop processes and controls to completely eliminate or mitigate their occurrence or effects.Cybersecurity incidents could also affect issuers of securities in which the Fund invests, leading to significant loss of value.

Recent Market Conditions. The financial crisis that began in 2008 was followed in many Western countries by a long period ofgrowth that was slower than the historical average, the disappearance of some traditional industries and jobs, and an unevendistribution of economic opportunities. This in turn has spurred some countries, including the U.S., to adopt or consideradopting more protectionist trade policies, to signal a move away from the tighter financial industry regulations that followed thecrisis, and to consider reducing corporate taxes. The U.S. is also said to be considering significant new investments ininfrastructure and national defense which, coupled with the prospect of lower federal taxes, could lead to sharply increasedgovernment borrowing and higher interest rates. The exact shape of these policies is still being worked out through the politicalprocess, but the equity and debt markets may react strongly to expectations, which could increase volatility, especially if themarket’s expectations for changes in government policies are not borne out.

High public debt in the U.S. and other countries creates ongoing systemic and market risks and policymaking uncertainty.Interest rates have been unusually low in recent years in the U.S. and abroad. Because there is little precedent for this situation, itis difficult to predict the impact on various markets of a significant rate increase or other significant policy changes, whetherbrought about by U.S. policy makers or by dislocations in world markets.

In addition, global economies and financial markets are increasingly interconnected, which increases the possibilities thatconditions in one country or region might adversely impact issuers in a different country or region. For example, official statisticsindicate a recent growth rate in China that is significantly lower than that in the early part of the decade. This has adverselyaffected worldwide commodity prices and the economies of many countries, especially those that depend heavily on commodityproduction and/or trade with China. A rise in protectionist trade policies, and the possibility of changes to some internationaltrade agreements, could affect the economies of many nations in ways that cannot necessarily be foreseen at the present time.

The severity or duration of adverse economic conditions may also be affected by policy changes made by governments or quasi-governmental organizations. Because the impact on the markets has been widespread, it may be difficult to identify both risks andopportunities using past models of the interplay of market forces, or to predict the duration of these market conditions.

Redemption Risk. The Fund may experience periods of heavy redemptions that could cause the Fund to sell assets atinopportune times or at a loss or depressed value. Redemption risk is heightened during periods of declining or illiquid markets.Heavy redemptions could hurt the Fund’s performance.

Risk Management. Risk is an essential part of investing. No risk management program can eliminate the Fund’s exposure toadverse events; at best, it may only reduce the possibility that the Fund will be affected by such events, and especially those risksthat are not intrinsic to the Fund’s investment program.

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Risk of Increase in Expenses. A decline in the Fund’s average net assets during the current fiscal year due to market volatility orother factors could cause the Fund’s expenses for the current fiscal year to be higher than the expense information presented in“Fees and Expenses.”

Sector Risk. From time to time, based on market or economic conditions, the Fund may have significant positions in one ormore sectors of the market. To the extent the Fund invests more heavily in particular sectors, its performance will be especiallysensitive to developments that significantly affect those sectors. Individual sectors may be more volatile, and may performdifferently, than the broader market. The industries that constitute a sector may all react in the same way to economic, political orregulatory events.

Social Investing Risk. The Fund may underperform similar funds that do not have a social policy because the Fund’s socialpolicy could cause it to sell or avoid stocks that subsequently perform well.

Valuation Risk. The Fund may not be able to sell an investment at the price at which the Fund has valued the investment. TheFund’s ability to value its investments in an accurate and timely manner may be impacted by technological issues and/or errors bythird party service providers, such as pricing services or accounting agents.

Value Stock Risk. Value stocks may remain undervalued or may decrease in value during a given period or may not ever realizewhat the portfolio management team believes to be their full value or intrinsic value. This may happen, among other reasons,because of a failure to anticipate which stocks or industries would benefit from changing market or economic conditions.

PERFORMANCEThe following bar chart and table provide an indication of the risks of investing in the Fund. The bar chart shows how the Fund’sperformance has varied from year to year. The table next to the bar chart shows what the returns would equal if you averaged outactual performance over various lengths of time and compares the returns with the returns of a broad-based market index. Theindex, which is described in “Description of Benchmark Index” in the prospectus, has characteristics relevant to the Fund’sinvestment strategy. The performance information does not reflect variable contract or qualified plan fees and expenses. If suchfees and expenses were reflected, returns would be less than those shown. Please refer to the prospectus for your variable contractor your qualified plan documentation for information on their separate fees and expenses.

Returns would have been lower if Neuberger Berman Investment Advisers LLC had not reimbursed certain expenses and/orwaived a portion of the investment management fees during certain of the periods shown.

Past performance is not a prediction of future results. Visit www.nb.com or call 800-877-9700 for updated performanceinformation.

YEAR-BY-YEAR % RETURNS AS OF 12/31 EACH YEAR

7.61

-39.44

31.43

22.85

-3.08

10.98

37.60

10.38

-0.46

9.86

2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

Best quarter: Q2 ’09, 15.74%Worst quarter: Q4 ’08, -27.01%

SOCIALLY RESPONSIVE PORTFOLIO May 1, 2017

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AVERAGE ANNUAL TOTAL % RETURNS AS OF 12/31/16

Socially Responsive Portfolio 1 Year 5 Years 10 Years

Class I 9.86 13.01 6.52

S&P 500® Index (reflects no deduction for fees, expenses or taxes) 11.96 14.66 6.95

INVESTMENT MANAGERNeuberger Berman Investment Advisers LLC (“Manager”) is the Fund’s investment manager.

PORTFOLIO MANAGERSThe Fund is managed by co-Portfolio Managers Ingrid S. Dyott (Managing Director of the Manager) and Sajjad S. Ladiwala,CFA (Managing Director of the Manager). Ms. Dyott became a co-Portfolio Manager of the Fund in 2003. Mr. Ladiwala joinedas an Associate Portfolio Manager in 2003 and became co-Portfolio Manager in 2016.

BUYING AND SELLING SHARESThe Fund is designed as a funding vehicle for certain variable contracts and qualified plans. Because shares of the Fund are held bythe insurance companies or qualified plans involved, you will need to follow the instructions provided by your insurance companyor qualified plan administrator for matters involving allocations to the Fund.

When shares of the Fund are bought and sold, the share price is the Fund’s net asset value per share. When shares are bought orsold, the share price will be the next share price calculated after the order has been received in proper form. Shares of the Fundmay be purchased or redeemed (sold) on any day the New York Stock Exchange is open.

TAX INFORMATIONDistributions made by the Fund to an insurance company separate account or a qualified plan, and exchanges and redemptions ofFund shares made by a separate account or qualified plan, ordinarily do not cause the contract holder or plan participant torecognize income or gain for federal income tax purposes. Please see your variable contract prospectus or the governing documentsof your qualified plan for information regarding the federal income tax treatment of the distributions to the applicable separateaccount or qualified plan and the holders of the contracts or plan participants, respectively.

PAYMENTS TO FINANCIAL INTERMEDIARIESNeuberger Berman BD LLC and/or its affiliates may pay insurance companies or their affiliates, qualified plan administrators,broker-dealers or other financial intermediaries, for services to current and prospective variable contract owners and qualified planparticipants who choose the Fund as an investment option. These payments may create a conflict of interest by influencing thefinancial intermediary and its employees to recommend the Fund over another investment or make the Fund available to theircurrent or prospective variable contract owners and qualified plan participants. Ask your financial intermediary or visit its websitefor more information.

The “Neuberger Berman” name and logo and “Neuberger Berman Investment Advisers LLC” are registered service marks of Neuberger Berman GroupLLC. The individual Fund name in this prospectus is either a service mark or a registered service mark of Neuberger Berman Investment Advisers LLC.©2017 Neuberger Berman BD LLC, distributor. All rights reserved.

SOCIALLY RESPONSIVE PORTFOLIO May 1, 2017

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SOCIALLY RESPONSIVE PORTFOLIO May 1, 2017

SEC File Number: 811-4255

K0055 05/17

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SUMMARY PROSPECTUS

U.S. STRATEGIC EQUITY FUND

(Formerly, Multi-Style Equity Fund)

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFAX

Investment Objective (Non-Fundamental)

The Fund seeks to provide long term capital growth.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.73%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.10%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.83%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same. This example does not reflect any Insurance Company Separate Account or Policycharges. If it did, the costs shown would have been higher. Although your actual costs may be higher or lower, underthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$85 $265 $460 $1,024

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” itsportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected inannual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, theFund’s portfolio turnover rate was 101% of the average value of its portfolio.

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Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund has a non-fundamental policy to invest, under normal circumstances, at least 80% of the value of its netassets plus borrowings for investment purposes in equity securities economically tied to the U.S. The Fund investsprincipally in common stocks of large and medium capitalization U.S. companies. The Fund defines large and mediumcapitalization stocks as stocks of those companies represented by the Russell 1000

®

Index or within the capitalizationrange of the Russell 1000

®

Index as measured at its most recent reconstitution.

Russell Investment Management, LLC (“RIM”) provides or oversees the provision of all investment advisory andportfolio management services for the Fund, including developing the investment program for the Fund and managing theFund’s overall exposures. RIM employs a multi-style (growth, value and market-oriented) and multi-managerapproach for the Fund whereby RIM selects the investment strategies for the Fund and utilizes multiple money managersto pursue those strategies. The Fund employs discretionary and non-discretionary money managers. The Fund’sdiscretionary money managers select the individual portfolio instruments for the assets assigned to them. The Fund’snon-discretionary money managers provide a model portfolio to RIM representing their investment recommendations,based upon which RIM purchases and sells securities for the Fund. RIM manages Fund assets not allocated todiscretionary money managers, which include assets managed by RIM to effect the Fund’s investment strategies and/orto actively manage the Fund’s overall exposures to seek to achieve the desired risk/return profile for the Fund. RIM mayutilize quantitative or qualitative analysis or quantitative models designed to assess Fund characteristics and identify aportfolio which provides the desired exposures or use strategies based on indexes that represent the desired exposures,including index replication and optimized index sampling (strategies that seek to purchase the securities in an index or asampling of securities using optimization and risk models, respectively). RIM also manages the portion of Fund assets forwhich the Fund’s non-discretionary money managers provide model portfolios and the Fund’s cash balances. The Fundusually, but not always, pursues a strategy to be fully invested by exposing all or a portion of its cash to the performanceof appropriate markets by purchasing equity securities and/or derivatives, which typically include index futures contracts.

The Fund may also invest in securities of non-U.S. issuers by purchasing American Depositary Receipts (“ADRs”) orGlobal Depositary Receipts (“GDRs”). Please refer to the “Investment Objective and Investment Strategies” section in theFund’s Prospectus for further information.

Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Active Management. Despite strategies designed to achieve the Fund’s investment objective, the value ofinvestments will change with market conditions, and so will the value of any investment in the Fund and youcould lose money. The securities selected for the portfolio may not perform as RIM or the Fund’s money managersexpect. Additionally, securities selected may cause the Fund to underperform relative to other funds with similarinvestment objectives and strategies. There is no guarantee that RIM will effectively assess the Fund’sportfolio characteristics and it is possible that its judgments regarding the Fund’s risk/return profile may proveincorrect. In addition, actions taken to actively manage overall Fund exposures, including risk, may be ineffectiveand/or cause the Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

• Index-Based Investing. Index-based strategies, which may be used to actively manage the Fund’s overallexposures, may cause the Fund’s returns to be lower than if the Fund employed a fundamental investmentapproach to security selection with respect to that portion of its portfolio. Additionally, index-based strategies aresubject to “tracking error” risk, which is the risk that the performance of the portion of the Fund’s portfolioutilizing an index-based strategy will differ from the performance of the index it seeks to track.

• Non-Discretionary Implementation Risk. With respect to the portion of the Fund that is managed pursuant to modelportfolios provided by non-discretionary money managers, it is expected that trades will be effected on a periodic

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basis and therefore less frequently than would typically be the case if discretionary money managers wereemployed. Given that values of investments change with market conditions, this could cause the Fund’s return tobe lower than if the Fund employed discretionary money managers with respect to that portion of its portfolio.

• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s overall exposures. Securities selected usingquantitative analysis may perform differently than analysis of their historical trends would suggest. Inputs ormodels may be flawed or not work as anticipated and may cause the Fund to underperform other funds withsimilar investment objectives and strategies.

• Equity Securities. The value of equity securities will rise and fall in response to the activities of the company thatissued them, general market conditions and/or economic conditions. Investments in medium capitalizationcompanies may involve greater risks because these companies generally have narrower markets, more limitedmanagerial and financial resources and a less diversified product offering than larger, more established companies.Some medium capitalization stocks may also be thinly traded, and thus, difficult to buy and sell in the market.

• Depositary Receipts. Depositary receipts (including American Depositary Receipts and Global Depositary Receipts)are securities traded on a local stock exchange that represent securities issued by a foreign publicly-listed company.Depositary receipts are generally subject to the same risks of investing in the foreign securities they evidence orinto which they may be converted.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s losses may be greater if it invests in derivatives than if it invests only inconventional securities. The use of derivative instruments involves risks different from, and possibly greater than,the risks associated with investing directly in equity or fixed income securities, currencies or other instruments.Derivatives are subject to a number of risks such as leveraging risk, liquidity risk, market risk, credit risk, defaultrisk, counterparty risk (the risk that the other party in an agreement will fail to perform its obligations) andmanagement risk. They also involve the risk of mispricing or improper valuation and the risk that changes in thevalue of the derivative instrument may not correlate exactly with the change in the value of the underlying asset,rate or index.

• Large Redemptions. The Fund is used as an investment for certain funds of funds and in asset allocation programsand may have a large percentage of its Shares owned by such funds or held in such programs. Large redemptionactivity could result in the Fund incurring additional costs and being forced to sell portfolio securities at a loss tomeet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actionsdesigned to support the markets. Such events and conditions may adversely affect the value of the Fund’ssecurities, result in greater market or liquidity risk or cause difficulty valuing the Fund’s portfolio instruments orachieving the Fund’s objective.

Please refer to the “Risks” section in the Fund’s Prospectus for further information.

Performance

The following bar chart illustrates the risks of investing in the Fund by showing how the performance of the Fundvaries from year to year. The highest and lowest returns for a full quarter during the periods shown in the bar chart areset forth next to the bar chart. The performance results shown in this section do not reflect any Insurance CompanySeparate Account or Policy charges. Those charges, if included, would have reduced the performance results shown in thissection.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with the index returns that measure broad marketperformance.

Past performance is no indication of future results.

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Calendar Year Total Returns

-60.00%

-40.00%

-20.00%

0.00%

20.00%

40.00%

60.00%

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

10.36%(40.56)%

31.40%

16.46%

(1.55)%

15.69%

32.92%

11.70%1.11%

10.64%

Highest Quarterly Return:16.95% (3Q/09)

Lowest Quarterly Return:(25.23)% (4Q/08)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years 10 Years

U.S. Strategic Equity Fund . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.64% 13.95% 6.62%Russell 1000® Index (reflects no deduction for fees, expenses or taxes) . . . . . . . . . . . 12.05% 14.69% 7.08%

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to theRussell Indexes. Russell

®

is a trademark of Frank Russell Company.

Management

Investment Adviser

The Fund’s investment adviser is RIM. The Fund’s money managers are:

• Barrow, Hanley, Mewhinney & Strauss, LLC • Suffolk Capital Management, LLC• Jacobs Levy Equity Management, Inc. • William Blair Investment Management, LLC• Mar Vista Investment Partners, LLC

Portfolio Managers

James Barber, Chief Investment Officer of Equities, and Kevin Divney, a Senior Portfolio Manager, have primaryresponsibility for the management of the Fund. Mr. Barber and Mr. Divney have managed the Fund since April 2017.

Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premiumpayments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell InvestmentFunds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for moreinformation on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for Fund

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Shares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receivecompensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest byinfluencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

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RIF-6

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SUMMARY PROSPECTUS

U.S. SMALL CAP EQUITY FUND

(Formerly, Aggressive Equity Fund)

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFBX

Investment Objective (Non-Fundamental)

The Fund seeks to provide long term capital growth.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.90%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.12%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.02%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same. This example does not reflect any Insurance Company Separate Account or Policycharges. If it did, the costs shown would have been higher. Although your actual costs may be higher or lower, underthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$105 $326 $566 $1,253

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” itsportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected inannual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, theFund’s portfolio turnover rate was 106% of the average value of its portfolio.

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Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund has a non-fundamental policy to invest, under normal circumstances, at least 80% of the value of its netassets plus borrowings for investment purposes in small capitalization equity securities economically tied to the U.S. TheFund invests principally in common stocks of small capitalization U.S. companies, some of which are also consideredmicro capitalization U.S. companies. The Fund defines small capitalization stocks as stocks of those companiesrepresented by the Russell 2000

®

Index or within the capitalization range of the Russell 2000®

Index as measured at itsmost recent reconstitution.

Russell Investment Management, LLC (“RIM”) provides or oversees the provision of all investment advisory andportfolio management services for the Fund, including developing the investment program for the Fund and managing theFund’s overall exposures. RIM employs a multi-style (growth, value, market-oriented, defensive and/or dynamic) andmulti-manager approach for the Fund whereby RIM selects the investment strategies for the Fund and utilizes multiplemoney managers to pursue those strategies. The Fund’s money managers have non-discretionary asset managementassignments pursuant to which they provide a model portfolio to RIM representing their investment recommendations,based upon which RIM purchases and sells securities for the Fund. RIM also manages the portion of the Fund’s assetsthat RIM determines not to manage based upon model portfolios provided by the Fund’s money managers. This includesassets managed directly by RIM to effect the Fund’s investment strategies and/or to actively manage the Fund’s overallexposures to seek to achieve the desired risk/return profile for the Fund. RIM may utilize quantitative or qualitativeanalysis or quantitative models designed to assess Fund characteristics and identify a portfolio which provides the desiredexposures or use strategies based on indexes that represent the desired exposures, including index replication andoptimized index sampling (strategies that seek to purchase the securities in an index or a sampling of securities usingoptimization and risk models, respectively). RIM also manages the Fund’s cash balances. The Fund usually, but notalways, pursues a strategy to be fully invested by exposing all or a portion of its cash to the performance of appropriatemarkets by purchasing equity securities and/or derivatives, which typically include index futures contracts.

The Fund may also invest in securities of non-U.S. issuers by purchasing American Depositary Receipts (“ADRs”) orGlobal Depositary Receipts (“GDRs”). The Fund may invest a portion of its assets in securities of companies, known asreal estate investment trusts (“REITs”), that own and/or manage properties. Please refer to the “Investment Objective andInvestment Strategies” section in the Fund’s Prospectus for further information.

Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Active Management. Despite strategies designed to achieve the Fund’s investment objective, the value ofinvestments will change with market conditions, and so will the value of any investment in the Fund and youcould lose money. The securities selected for the portfolio may not perform as RIM or the Fund’s money managersexpect. Additionally, securities selected may cause the Fund to underperform relative to other funds with similarinvestment objectives and strategies. There is no guarantee that RIM will effectively assess the Fund’sportfolio characteristics and it is possible that its judgments regarding the Fund’s risk/return profile may proveincorrect. In addition, actions taken to actively manage overall Fund exposures, including risk, may be ineffectiveand/or cause the Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

• Index-Based Investing. Index-based strategies, which may be used to actively manage the Fund’s overallexposures, may cause the Fund’s returns to be lower than if the Fund employed a fundamental investmentapproach to security selection with respect to that portion of its portfolio. Additionally, index-based strategies aresubject to “tracking error” risk, which is the risk that the performance of the portion of the Fund’s portfolioutilizing an index-based strategy will differ from the performance of the index it seeks to track.

• Non-Discretionary Implementation Risk. With respect to the portion of the Fund that is managed pursuant to modelportfolios provided by non-discretionary money managers, it is expected that trades will be effected on a periodic

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basis and therefore less frequently than would typically be the case if discretionary money managers wereemployed. Given that values of investments change with market conditions, this could cause the Fund’s return tobe lower than if the Fund employed discretionary money managers with respect to that portion of its portfolio.

• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s overall exposures. Securities selected usingquantitative analysis may perform differently than analysis of their historical trends would suggest. Inputs ormodels may be flawed or not work as anticipated and may cause the Fund to underperform other funds withsimilar investment objectives and strategies.

• Equity Securities. The value of equity securities will rise and fall in response to the activities of the company thatissued them, general market conditions and/or economic conditions. Investments in small and micro capitalizationcompanies may involve greater risks because these companies generally have narrower markets, more limitedmanagerial and financial resources and a less diversified product offering than larger, more established companies.Small and micro capitalization stocks may also be thinly traded, and thus, difficult to buy and sell in the market.Micro capitalization company stocks are also more likely to suffer from significantly diminished market liquidity.

• Real Estate Investment Trusts (“REITs”). REITs may be affected by changes in the value of the underlyingproperties owned by the REITs and by the quality of tenants’ credit.

• Depositary Receipts. Depositary receipts (including American Depositary Receipts and Global Depositary Receipts)are securities traded on a local stock exchange that represent securities issued by a foreign publicly-listed company.Depositary receipts are generally subject to the same risks of investing in the foreign securities they evidence orinto which they may be converted.

• Liquidity Risk. The market for certain investments may become illiquid under adverse or volatile market oreconomic conditions, making those investments difficult to sell. The market price of certain investments may falldramatically if there is no liquid trading market.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s losses may be greater if it invests in derivatives than if it invests only inconventional securities. The use of derivative instruments involves risks different from, and possibly greater than,the risks associated with investing directly in equity or fixed income securities, currencies or other instruments.Derivatives are subject to a number of risks such as leveraging risk, liquidity risk, market risk, credit risk, defaultrisk, counterparty risk (the risk that the other party in an agreement will fail to perform its obligations) andmanagement risk. They also involve the risk of mispricing or improper valuation and the risk that changes in thevalue of the derivative instrument may not correlate exactly with the change in the value of the underlying asset,rate or index.

• Large Redemptions. The Fund is used as an investment for certain funds of funds and in asset allocation programsand may have a large percentage of its Shares owned by such funds or held in such programs. Large redemptionactivity could result in the Fund incurring additional costs and being forced to sell portfolio securities at a loss tomeet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actionsdesigned to support the markets. Such events and conditions may adversely affect the value of the Fund’ssecurities, result in greater market or liquidity risk or cause difficulty valuing the Fund’s portfolio instruments orachieving the Fund’s objective.

Please refer to the “Risks” section in the Fund’s Prospectus for further information.

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Performance

The following bar chart illustrates the risks of investing in the Fund by showing how the performance of the Fundvaries from year to year. The highest and lowest returns for a full quarter during the periods shown in the bar chart areset forth next to the bar chart. The performance results shown in this section do not reflect any Insurance CompanySeparate Account or Policy charges. Those charges, if included, would have reduced the performance results shown in thissection.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with the index returns that measure broad marketperformance. Effective May 1, 2012, RIM changed the Fund’s primary benchmark from the Russell 2500™ Index to theRussell 2000

®

Index. The U.S. Small Cap Equity Linked Benchmark (formerly named the Aggressive Equity LinkedBenchmark) represents the returns of the Russell 2500™ Index through April 30, 2012 and the returns of the Russell2000

®

Index thereafter. The U.S. Small Cap Equity Linked Benchmark provides a means to compare the Fund’s averageannual returns to a secondary benchmark that takes into account historical changes in the Fund’s primary benchmark.

Past performance is no indication of future results.

Calendar Year Total Returns

-60.00%

-40.00%

-20.00%

0.00%

20.00%

40.00%

60.00%

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

3.42% (42.92)%

31.39%24.88%

(4.20)%

15.84%

40.00%

1.56% (7.19)%

18.66%Highest Quarterly Return:

21.25% (2Q/09)

Lowest Quarterly Return:(28.07)% (4Q/08)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years 10 Years

U.S. Small Cap Equity Fund . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.66% 12.65% 5.34%Russell 2000® Index (reflects no deduction for fees, expenses or taxes) . . . . . . . . . . 21.31% 14.46% 7.07%U.S. Small Cap Equity Linked Benchmark (reflects no deduction for fees, expensesor taxes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.31% 14.72% 7.77%

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to theRussell Indexes. Russell

®

is a trademark of Frank Russell Company.

Management

Investment Adviser

The Fund’s investment adviser is RIM. The Fund’s money managers are:

• DePrince, Race & Zollo, Inc. • Snow Capital Management L.P.• Monarch Partners Asset Management, LLC • Timpani Capital Management LLC• RBC Global Asset Management (U.S.) Inc.

Portfolio Managers

Jon Eggins, a Senior Portfolio Manager, and Megan Roach, a Portfolio Manager, have primary responsibility for themanagement of the Fund. Mr. Eggins has managed the Fund since May 2011 and Ms. Roach has managed the Fund sinceMarch 2015.

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Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premiumpayments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell InvestmentFunds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for moreinformation on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for FundShares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receivecompensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest byinfluencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

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SUMMARY PROSPECTUS

GLOBAL REAL ESTATE SECURITIES FUND

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFSX

Investment Objective (Non-Fundamental)

The Fund seeks to provide current income and long term capital growth.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.80%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.10%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.90%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same. This example does not reflect any Insurance Company Separate Account or Policycharges. If it did, the costs shown would have been higher. Although your actual costs may be higher or lower, underthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$92 $288 $500 $1,111

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” itsportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected inannual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, theFund’s portfolio turnover rate was 91% of the average value of its portfolio.

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Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund has a non-fundamental policy to invest, under normal circumstances, at least 80% of the value of its netassets plus borrowings for investment purposes in real estate securities. The Fund seeks to achieve its objective byconcentrating its investments in equity securities of real estate companies economically tied to a number of countriesaround the world, including the U.S., in a globally diversified manner. The Fund invests principally in securities ofcompanies, known as real estate investment trusts (“REITs”) and other REIT-like entities that own interests in real estateor real estate-related loans. The Fund may also invest in equity securities of other types of real estate-related companies.A portion of the Fund’s securities are denominated in foreign currencies and are typically held outside the U.S. The Fundmay invest a portion of its assets in equity securities of companies that are located in emerging markets. The Fundconsiders emerging market countries to include every country in the world except Australia, Austria, Belgium, Canada,Denmark, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, Luxembourg, the Netherlands, NewZealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland, the United Kingdom and the United States.

Russell Investment Management, LLC (“RIM”) provides or oversees the provision of all investment advisory andportfolio management services for the Fund, including developing the investment program for the Fund and managing theFund’s overall exposures. RIM employs a multi-manager approach for the Fund whereby RIM selects the investmentstrategies for the Fund and utilizes multiple money managers to pursue those strategies. RIM manages Fund assets notallocated to money managers, which include assets managed by RIM to effect the Fund’s investment strategies and/or toactively manage the Fund’s overall exposures to seek to achieve the desired risk/return profile for the Fund. RIM mayutilize quantitative or qualitative analysis or quantitative models designed to assess Fund characteristics and identify aportfolio which provides the desired exposures or use strategies based on indexes that represent the desired exposures,including index replication and optimized index sampling (strategies that seek to purchase the securities in an index or asampling of securities using optimization and risk models, respectively). RIM also manages the Fund’s cash balances. TheFund usually, but not always, pursues a strategy to be fully invested by exposing all or a portion of its cash to theperformance of certain real estate securities or, in certain circumstances, broad global equity markets by purchasing equitysecurities and/or derivatives, which typically include index futures contracts and swaps.

The Fund may enter into spot or forward currency contracts to facilitate settlement of securities transactions. TheFund may invest in large, medium or small capitalization companies. Please refer to the “Investment Objective andInvestment Strategies” section in the Fund’s Prospectus for further information.

Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Active Management. Despite strategies designed to achieve the Fund’s investment objective, the value ofinvestments will change with market conditions, and so will the value of any investment in the Fund and youcould lose money. The securities selected for the portfolio may not perform as RIM or the Fund’s money managersexpect. Additionally, securities selected may cause the Fund to underperform relative to other funds with similarinvestment objectives and strategies. There is no guarantee that RIM will effectively assess the Fund’sportfolio characteristics and it is possible that its judgments regarding the Fund’s risk/return profile may proveincorrect. In addition, actions taken to actively manage overall Fund exposures, including risk, may be ineffectiveand/or cause the Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

• Index-Based Investing. Index-based strategies, which may be used to actively manage the Fund’s overallexposures, may cause the Fund’s returns to be lower than if the Fund employed a fundamental investmentapproach to security selection with respect to that portion of its portfolio. Additionally, index-based strategies aresubject to “tracking error” risk, which is the risk that the performance of the portion of the Fund’s portfolioutilizing an index-based strategy will differ from the performance of the index it seeks to track.

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• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s overall exposures. Securities selected usingquantitative analysis may perform differently than analysis of their historical trends would suggest. Inputs ormodels may be flawed or not work as anticipated and may cause the Fund to underperform other funds withsimilar investment objectives and strategies.

• Equity Securities. The value of equity securities will rise and fall in response to the activities of the company thatissued them, general market conditions and/or economic conditions. Investments in small and mediumcapitalization companies may involve greater risks because these companies generally have narrower markets,more limited managerial and financial resources and a less diversified product offering than larger, moreestablished companies. Small and some medium capitalization stocks may also be thinly traded, and thus, difficultto buy and sell in the market.

• Real Estate Securities. Just as real estate values go up and down, the value of the securities of companies involvedin the industry also fluctuates. Real estate securities, including real estate investment trusts (“REITs”), may beaffected by changes in the value of the underlying properties owned by the companies and by the quality oftenants’ credit.

• Non-U.S. and Emerging Markets Securities. Non-U.S. securities have risks relating to political, economic andregulatory conditions in foreign countries. The risks associated with non-U.S. securities may be amplified foremerging markets securities.

• Currency Risk. Non-U.S. securities that trade in, and receive revenues in, non-U.S. currencies are subject to therisk that those currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, thatthe U.S. dollar will decline in value relative to the currency being hedged. As a result, investments in non-U.S.dollar-denominated securities and currencies may reduce the returns of the Fund.

• Counterparty Risk. Counterparty risk is the risk that the other party or parties to an agreement or a participant to atransaction, such as a broker, might default on a contract or fail to perform by failing to pay amounts due orfailing to fulfill the obligations of the contract or transaction.

• Liquidity Risk. The market for certain investments may become illiquid under adverse or volatile market oreconomic conditions, making those investments difficult to sell. The market price of certain investments may falldramatically if there is no liquid trading market.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s losses may be greater if it invests in derivatives than if it invests only inconventional securities. The use of derivative instruments involves risks different from, and possibly greater than,the risks associated with investing directly in equity or fixed income securities, currencies or other instruments.Derivatives are subject to a number of risks such as leveraging risk, liquidity risk, market risk, credit risk, defaultrisk, counterparty risk (the risk that the other party in an agreement will fail to perform its obligations) andmanagement risk. They also involve the risk of mispricing or improper valuation and the risk that changes in thevalue of the derivative instrument may not correlate exactly with the change in the value of the underlying asset,rate or index.

• Currency Trading Risk. Currency trading strategies may involve instruments that have volatile prices, are illiquidor create economic leverage. Forward currency contracts are subject to the risk that, should forward pricesincrease, a loss will be incurred to the extent that the price of the currency agreed to be purchased exceeds theprice of the currency agreed to be sold.

• Large Redemptions. The Fund is used as an investment for certain funds of funds and in asset allocation programsand may have a large percentage of its Shares owned by such funds or held in such programs. Large redemptionactivity could result in the Fund incurring additional costs and being forced to sell portfolio securities at a loss tomeet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actions

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designed to support the markets. Such events and conditions may adversely affect the value of the Fund’ssecurities, result in greater market or liquidity risk or cause difficulty valuing the Fund’s portfolio instruments orachieving the Fund’s objective.

• Industry Concentration Risk. By concentrating in a single industry, the Fund carries much greater risk of adversedevelopments in that industry than a fund that invests in a wide variety of industries.

Please refer to the “Risks” section in the Fund’s Prospectus for further information.

Performance

The following bar chart illustrates the risks of investing in the Fund by showing how the performance of the Fundvaries from year to year. The highest and lowest returns for a full quarter during the periods shown in the bar chart areset forth next to the bar chart. The performance results shown in this section do not reflect any Insurance CompanySeparate Account or Policy charges. Those charges, if included, would have reduced the performance results shown in thissection.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with the index returns that measure broad marketperformance. In October 2010, RIM changed the Fund’s primary benchmark from the FTSE NAREIT Equity REIT Indexto the FTSE EPRA/NAREIT Developed Real Estate Index (net of tax on dividends from foreign holdings). The GlobalReal Estate Linked Benchmark represents the returns of the FTSE NAREIT Equity REIT Index through September 30,2010 and the returns of the FTSE EPRA/NAREIT Developed Real Estate Index (net of tax on dividends from foreignholdings) thereafter. The Global Real Estate Linked Benchmark provides a means to compare the Fund’s average annualreturns to a secondary benchmark that takes into account historical changes in the Fund’s primary benchmark. The RussellDeveloped Index (net of tax on dividends from foreign holdings) measures the performance of the investable securities indeveloped countries globally.

Past performance is no indication of future results.

Calendar Year Total Returns

-40.00%

-20.00%

0.00%

20.00%

40.00%

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

(15.86)% (36.68)%

28.94%22.92%

(7.05)%

27.56%

3.65%

14.75%

0.25% 3.02%

Highest Quarterly Return:30.01% (3Q/09)

Lowest Quarterly Return:(36.97)% (4Q/08)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years 10 Years

Global Real Estate Securities Fund . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.02% 9.40% 2.09%FTSE EPRA/NAREIT Developed Real Estate Index (net of tax on dividends fromforeign holdings) (reflects no deduction for fees or expenses) . . . . . . . . . . . . . . . . . . . 4.06% 9.48% 1.48%Global Real Estate Linked Benchmark (reflects no deduction for fees, expenses ortaxes). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.06% 9.48% 2.24%Russell Developed Index (net of tax on dividends from foreign holdings) (reflectsno deduction for fees or expenses) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.18% 10.74% 4.09%

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to theRussell Indexes. Russell

®

is a trademark of Frank Russell Company.

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Management

Investment Adviser

The Fund’s investment adviser is RIM. The Fund’s money managers are:

• Cohen & Steers Capital Management, Inc., Cohen &Steers UK Limited and Cohen & Steers Asia Limited

• RREEF America L.L.C., Deutsche InvestmentsAustralia Limited and Deutsche Alternatives AssetManagement (Global) Limited, operating under thebrand name Deutsche Asset Management

• Morgan Stanley Investment Management Inc., MorganStanley Investment Management Limited and MorganStanley Investment Management Company

Portfolio Manager

Bruce Eidelson, a Senior Portfolio Manager, and Patrick Nikodem, a Portfolio Manager, have primary responsibilityfor the management of the Fund. Mr. Eidelson has managed the Fund since January 2002 and Mr. Nikodem has managedthe Fund since December 2016.

Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premiumpayments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell InvestmentFunds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for moreinformation on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for FundShares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receive

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compensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest byinfluencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

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SUMMARY PROSPECTUS

INTERNATIONAL DEVELOPED MARKETS FUND

(Formerly, Non-U.S. Fund)

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFCX

Investment Objective (Non-Fundamental)

The Fund seeks to provide long term capital growth.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.90%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.12%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.02%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same. This example does not reflect any Insurance Company Separate Account or Policycharges. If it did, the costs shown would have been higher. Although your actual costs may be higher or lower, underthese assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$104 $324 $562 $1,246

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” itsportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected inannual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, theFund’s portfolio turnover rate was 36% of the average value of its portfolio.

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Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund has a non-fundamental policy to invest, under normal circumstances, at least 80% of the value of its netassets plus borrowings for investment purposes in companies that are located in countries (other than the U.S.) withdeveloped markets or that are economically tied to such countries. The Fund invests principally in equity securities,including common stocks and preferred stocks, issued by companies incorporated in developed markets outside the U.S.and in depositary receipts. The Fund’s securities are denominated principally in foreign currencies and are typically heldoutside the U.S. The Fund may invest a portion of its assets in equity securities of companies that are economically tiedto emerging market countries. The Fund considers the following countries to have developed markets: Australia, Austria,Belgium, Canada, Denmark, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, Luxembourg, theNetherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland, the United Kingdom and theUnited States. As a general rule, the Fund considers emerging market countries to include every other country. The Fundinvests principally in large and medium capitalization companies, but may also invest in small capitalization companies.The Fund defines large and medium capitalization stocks as stocks of those companies represented by the RussellDeveloped ex-U.S. Large Cap Index or within the capitalization range of the Russell Developed ex-U.S. Large Cap Indexas measured at its most recent reconstitution.

Russell Investment Management, LLC (“RIM”) provides or oversees the provision of all investment advisory andportfolio management services for the Fund, including developing the investment program for the Fund and managing theFund’s overall exposures. RIM employs a multi-style (growth, value, market-oriented and defensive) and multi-managerapproach for the Fund whereby RIM selects the investment strategies for the Fund and utilizes multiple money managersto pursue those strategies. RIM manages assets not allocated to money managers, which include assets managed by RIMto effect the Fund’s investment strategies and/or to actively manage the Fund’s overall exposures to seek to achieve thedesired risk/return profile for the Fund. RIM may utilize quantitative or qualitative analysis or quantitative modelsdesigned to assess Fund characteristics and identify a portfolio which provides the desired exposures or use strategiesbased on indexes that represent the desired exposures, including index replication and optimized index sampling(strategies that seek to purchase the securities in an index or a sampling of securities using optimization and risk models,respectively). RIM also manages the Fund’s cash balances. The Fund usually, but not always, pursues a strategy to befully invested by exposing all or a portion of its cash to the performance of appropriate markets by purchasing equitysecurities and/or derivatives, which typically include index futures contracts and forward currency contracts. The Fundmay use derivatives, including stock options, country index futures and swaps or currency forwards, to (1) managecountry and currency exposure as a substitute for holding securities directly or (2) facilitate the implementation of itsinvestment strategy. The Fund may use derivatives to take both long and short positions.

The Fund may at times seek to protect a portion of its investments against adverse currency exchange rate changesby purchasing forward currency contracts and may engage in currency transactions for speculative purposes. Please referto the “Investment Objective and Investment Strategies” section in the Fund’s Prospectus for further information.

Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Active Management. Despite strategies designed to achieve the Fund’s investment objective, the value ofinvestments will change with market conditions, and so will the value of any investment in the Fund and youcould lose money. The securities selected for the portfolio may not perform as RIM or the Fund’s money managersexpect. Additionally, securities selected may cause the Fund to underperform relative to other funds with similarinvestment objectives and strategies. There is no guarantee that RIM will effectively assess the Fund’sportfolio characteristics and it is possible that its judgments regarding the Fund’s risk/return profile may proveincorrect. In addition, actions taken to actively manage overall Fund exposures, including risk, may be ineffectiveand/or cause the Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

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• Index-Based Investing. Index-based strategies, which may be used to actively manage the Fund’s overallexposures, may cause the Fund’s returns to be lower than if the Fund employed a fundamental investmentapproach to security selection with respect to that portion of its portfolio. Additionally, index-based strategies aresubject to “tracking error” risk, which is the risk that the performance of the portion of the Fund’s portfolioutilizing an index-based strategy will differ from the performance of the index it seeks to track.

• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s overall exposures. Securities selected usingquantitative analysis may perform differently than analysis of their historical trends would suggest. Inputs ormodels may be flawed or not work as anticipated and may cause the Fund to underperform other funds withsimilar investment objectives and strategies.

• Equity Securities. The value of equity securities will rise and fall in response to the activities of the company thatissued them, general market conditions and/or economic conditions. Investments in small and mediumcapitalization companies may involve greater risks because these companies generally have narrower markets,more limited managerial and financial resources and a less diversified product offering than larger, moreestablished companies. Small and some medium capitalization stocks may also be thinly traded, and thus, difficultto buy and sell in the market. Investments in preferred stocks are subject to the risks of common stocks, as well asthe risk that interest rates will rise and make the fixed dividend feature, if any, less appealing to investors resultingin a decline in price.

• Non-U.S. and Emerging Markets Securities. Non-U.S. securities have risks relating to political, economic andregulatory conditions in foreign countries. The risks associated with non-U.S. securities may be amplified foremerging markets securities.

• Currency Risk. Non-U.S. securities that trade in, and receive revenues in, non-U.S. currencies are subject to therisk that those currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, thatthe U.S. dollar will decline in value relative to the currency being hedged. As a result, investments in non-U.S.dollar-denominated securities and currencies may reduce the returns of the Fund.

• Counterparty Risk. Counterparty risk is the risk that the other party or parties to an agreement or a participant to atransaction, such as a broker, might default on a contract or fail to perform by failing to pay amounts due orfailing to fulfill the obligations of the contract or transaction.

• Depositary Receipts. Depositary receipts (including American Depositary Receipts and Global Depositary Receipts)are securities traded on a local stock exchange that represent securities issued by a foreign publicly-listed company.Depositary receipts are generally subject to the same risks of investing in the foreign securities they evidence orinto which they may be converted.

• Liquidity Risk. The market for certain investments may become illiquid under adverse or volatile market oreconomic conditions, making those investments difficult to sell. The market price of certain investments may falldramatically if there is no liquid trading market.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s losses may be greater if it invests in derivatives than if it invests only inconventional securities. The use of derivative instruments involves risks different from, and possibly greater than,the risks associated with investing directly in equity or fixed income securities, currencies or other instruments.Derivatives are subject to a number of risks such as leveraging risk, liquidity risk, market risk, credit risk, defaultrisk, counterparty risk (the risk that the other party in an agreement will fail to perform its obligations) andmanagement risk. They also involve the risk of mispricing or improper valuation and the risk that changes in thevalue of the derivative instrument may not correlate exactly with the change in the value of the underlying asset,rate or index.

• Currency Trading Risk. Currency trading strategies may involve instruments that have volatile prices, are illiquidor create economic leverage. Forward currency contracts are subject to the risk that, should forward pricesincrease, a loss will be incurred to the extent that the price of the currency agreed to be purchased exceeds theprice of the currency agreed to be sold.

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• Large Redemptions. The Fund is used as an investment for certain funds of funds and in asset allocation programsand may have a large percentage of its Shares owned by such funds or held in such programs. Large redemptionactivity could result in the Fund incurring additional costs and being forced to sell portfolio securities at a loss tomeet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actionsdesigned to support the markets. Such events and conditions may adversely affect the value of the Fund’ssecurities, result in greater market or liquidity risk or cause difficulty valuing the Fund’s portfolio instruments orachieving the Fund’s objective.

Please refer to the “Risks” section in the Fund’s Prospectus for further information.

Performance

The following bar chart illustrates the risks of investing in the Fund by showing how the performance of the Fundvaries from year to year. The highest and lowest returns for a full quarter during the periods shown in the bar chart areset forth next to the bar chart. The performance results shown in this section do not reflect any Insurance CompanySeparate Account or Policy charges. Those charges, if included, would have reduced the performance results shown in thissection.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with the index returns that measure broad marketperformance. Effective January 1, 2011, RIM changed the Fund’s primary benchmark from the MSCI EAFE Index (net oftax on dividends from foreign holdings) to the Russell Developed ex-U.S. Large Cap Index (net of tax on dividends fromforeign holdings). The International Developed Markets Linked Benchmark represents the returns of the MSCI EAFEIndex (net of tax on dividends from foreign holdings) through December 31, 2010 and the returns of the RussellDeveloped ex-U.S. Large Cap Index (net of tax on dividends from foreign holdings) thereafter. The InternationalDeveloped Markets Linked Benchmark provides a means to compare the Fund’s average annual returns to a secondarybenchmark that takes into account historical changes in the Fund’s primary benchmark.

Past performance is no indication of future results.

Calendar Year Total Returns

-60.00%

-40.00%

-20.00%

0.00%

20.00%

40.00%

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

10.12%(42.41)%

26.49%

11.42%

(12.88)%

19.81% 21.91%

(4.45)% (1.31)% 2.36%

Highest Quarterly Return:21.75% (2Q/09)

Lowest Quarterly Return:(20.89)% (3Q/11)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years 10 Years

International Developed Markets Fund . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.36% 7.11% 0.94%Russell Developed ex-U.S. Large Cap Index (net of tax on dividends from foreignholdings) (reflects no deduction for fees or expenses). . . . . . . . . . . . . . . . . . . . . . . . . . 2.42% 6.36% 1.14%International Developed Markets Linked Benchmark (reflects no deduction for feesor expenses) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.42% 6.36% 0.64%

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to theRussell Indexes. Russell

®

is a trademark of Frank Russell Company.

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Management

Investment Adviser

The Fund’s investment adviser is RIM. The Fund’s money managers are:

• Barrow, Hanley, Mewhinney & Strauss, LLC • Pzena Investment Management, LLC• GQG Partners LLC • Wellington Management Company LLP• Numeric Investors LLC

Portfolio Managers

James Barber, Chief Investment Officer of Equities, and Jon Eggins, a Senior Portfolio Manager, have primaryresponsibility for the management of the Fund. Mr. Barber and Mr. Eggins have managed the Fund since February 2015.

Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premiumpayments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell InvestmentFunds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for moreinformation on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for FundShares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receivecompensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest by

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influencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

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SUMMARY PROSPECTUS

STRATEGIC BOND FUND

(Formerly, Core Bond Fund)

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFDX

Investment Objective (Non-Fundamental)

The Fund seeks to provide current income, and as a secondary objective, capital appreciation.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)#

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.55%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.09%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.64%

# “Other Expenses” and “Total Annual Fund Operating Expenses” have been restated to reflect the Fund’s proportionate share of the operatingexpenses of any other fund in which the Fund invests, including the U.S. Cash Management Fund.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same (taking into account fee waivers/reimbursements in year 1 only). This example doesnot reflect any Insurance Company Separate Account or Policy charges. If it did, the costs shown would have beenhigher. Although your actual costs may be higher or lower, under these assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$66 $206 $359 $803

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Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” itsportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected inannual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, theFund’s portfolio turnover rate was 262% of the average value of its portfolio.

Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund has a non-fundamental policy to invest, under normal circumstances, at least 80% of the value of its netassets plus borrowings for investment purposes in bonds.

Russell Investment Management, LLC (“RIM”) provides or oversees the provision of all investment advisory andportfolio management services for the Fund, including developing the investment program for the Fund and managing theFund’s overall exposures. RIM employs a multi-manager approach for the Fund whereby RIM selects the investmentstrategies for the Fund and utilizes multiple money managers to pursue those strategies. RIM manages assets not allocatedto money managers, which include assets managed by RIM to effect the Fund’s investment strategies and/or to activelymanage the Fund’s overall exposures to seek to achieve the desired risk/return profile for the Fund. RIM may utilizequantitative or qualitative analysis or quantitative models designed to assess Fund characteristics and identify a portfoliowhich provides the desired exposures or use strategies based on indexes that represent the desired exposures, includingindex replication and optimized index sampling (strategies that seek to purchase the securities in an index or a samplingof securities using optimization and risk models, respectively). RIM also manages the Fund’s cash balances.

The Fund invests in mortgage related securities, including mortgage-backed securities. The Fund also invests in(1) U.S. and non-U.S. corporate debt securities, (2) Yankee Bonds (dollar-denominated obligations issued in the U.S. bynon-U.S. banks and corporations), (3) fixed income securities issued or guaranteed by the U.S. government, non-U.S.governments, or by any U.S. government or non-U.S. government agency or instrumentality and (4) asset-backedsecurities. The Fund may invest in debt securities that are rated below investment grade (commonly referred to as“high-yield” or “junk bonds”). The Fund may invest in currency futures and options on futures, forward currencycontracts, currency swaps and currency options for speculative purposes or to seek to protect a portion of its investmentsagainst adverse currency exchange rate changes. The Fund invests in derivative instruments and may use derivativesto take both long and short positions. The Fund’s use of derivatives may cause the Fund’s investment returns to beimpacted by the performance of securities the Fund does not own and result in the Fund’s total investment exposureexceeding the value of its portfolio. The duration of the Fund’s portfolio typically ranges within 20% of the duration ofthe Bloomberg Barclays U.S. Aggregate Bond Index, but may vary up to 35% from the Index’s duration. A portion of theFund’s net assets may be illiquid. The Fund may invest in variable and floating rate securities. The Fund purchases loansand other direct indebtedness, including bank loans (also called “leveraged loans”). The Fund invests in non-U.S. debtsecurities, including developed and emerging market debt securities, some of which may be non-U.S. dollar denominated.The Fund considers the following countries to have developed markets: Australia, Austria, Belgium, Canada, Denmark,Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, Luxembourg, the Netherlands, New Zealand, Norway,Portugal, Singapore, Spain, Sweden, Switzerland, the United Kingdom and the United States. As a general rule, the Fundconsiders emerging market countries to include every other country. The Fund may enter into repurchase agreements. TheFund may invest in commercial paper, including asset-backed commercial paper. The Fund usually, but not always,pursues a strategy to be fully invested by exposing all or a portion of its cash to changes in interest rates or market/sectorreturns by purchasing fixed income securities and/or derivatives, which typically include exchange traded fixed incomefutures contracts, to be announced (“TBA”) securities and swaps. Please refer to the “Investment Objective andInvestment Strategies” section in the Fund’s Prospectus for further information.

Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Active Management. Despite strategies designed to achieve the Fund’s investment objective, the value ofinvestments will change with market conditions, and so will the value of any investment in the Fund and youcould lose money. The securities selected for the portfolio may not perform as RIM or the Fund’s money managers

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expect. Additionally, securities selected may cause the Fund to underperform relative to other funds with similarinvestment objectives and strategies. There is no guarantee that RIM will effectively assess the Fund’sportfolio characteristics and it is possible that its judgments regarding the Fund’s risk/return profile may proveincorrect. In addition, actions taken to actively manage overall Fund exposures, including risk, may be ineffectiveand/or cause the Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

• Index-Based Investing. Index-based strategies, which may be used to actively manage the Fund’s overallexposures, may cause the Fund’s returns to be lower than if the Fund employed a fundamental investmentapproach to security selection with respect to that portion of its portfolio. Additionally, index-based strategies aresubject to “tracking error” risk, which is the risk that the performance of the portion of the Fund’s portfolioutilizing an index-based strategy will differ from the performance of the index it seeks to track.

• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s overall exposures. Securities selected usingquantitative analysis may perform differently than analysis of their historical trends would suggest. Inputs ormodels may be flawed or not work as anticipated and may cause the Fund to underperform other funds withsimilar investment objectives and strategies.

• Fixed Income Securities. Prices of fixed income securities generally rise and fall in response to, among otherthings, interest rate changes. Volatility in interest rates and in fixed income markets may increase the risk that theFund’s investments in fixed income securities could lose money. In addition, the Fund could lose money if theissuer or guarantor of a fixed income security or other issuer of credit support is unable or unwilling to maketimely principal and/or interest payments, or to otherwise honor its obligations. Fixed income securities may bedowngraded in credit rating or go into default.

• Non-Investment Grade Debt Securities (“High Yield” or “Junk Bonds”). Non-investment grade debt securitiesinvolve higher volatility and higher risk of default than investment grade bonds.

• U.S. and Non-U.S. Corporate Debt Securities Risk. Investments in U.S. and non-U.S. corporate debt securities aresubject to interest rate risk and market risk, and are affected by perceptions of the creditworthiness and businessprospects of individual issuers. Non-U.S. corporate debt securities may expose the Fund to greater risk thaninvestments in U.S. corporate debt securities.

• Government Issued or Guaranteed Securities, U.S. Government Securities. Bonds issued or guaranteed by agovernment are subject to inflation risk, price depreciation risk and default risk.

• Money Market Securities (Including Commercial Paper). Prices of money market securities generally rise and fallin response to interest rate changes.

• Asset-Backed Commercial Paper. Investment in asset-backed commercial paper is subject to the risk thatinsufficient proceeds from the projected cash flows of the contributed receivables are available to repay thecommercial paper.

• Variable and Floating Rate Securities Risk. Variable and floating rate securities generally are less sensitive tointerest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interestrates in general.

• Mortgage-Backed Securities. Mortgage-backed securities may be affected by, among other things, changes orperceived changes in interest rates, factors concerning the interests in and structure of the issuer or the originatorof the mortgage, or the quality of the underlying assets. The underlying assets may default or decline in quality orvalue.

• Asset-Backed Securities. Payment of principal and interest on asset-backed securities may be largely dependentupon the cash flows generated by the assets backing the securities and asset-backed securities may not have thebenefit of any security interest in the related assets.

• Loans and Other Direct Indebtedness. Loans and other direct indebtedness involve the risk that payment ofprincipal, interest and other amounts due in connection with these investments may not be received. The highlyleveraged nature of many such loans, including bank loans, and other direct indebtedness may make such loans

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and other direct indebtedness especially vulnerable to adverse changes in economic or market conditions and/orchanges in the financial condition of the debtor. Investments in bank loans are typically subject to the risks offloating rate securities.

• Repurchase Agreements. Repurchase agreements are subject to the risk that the sellers may not be able to pay theagreed-upon repurchase price on the repurchase date.

• Non-U.S. and Emerging Markets Securities. Non-U.S. securities have risks relating to political, economic andregulatory conditions in foreign countries. The risks associated with non-U.S. securities may be amplified foremerging markets securities.

• Currency Risk. Non-U.S. securities that trade in, and receive revenues in, non-U.S. currencies are subject to therisk that those currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, thatthe U.S. dollar will decline in value relative to the currency being hedged. As a result, investments in non-U.S.dollar-denominated securities and currencies may reduce the returns of the Fund.

• Yankee Bonds and Yankee CDs. Issuers of Yankee Bonds and Yankee CDs are not necessarily subject to the sameregulatory requirements that apply to U.S. corporations and banks.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s losses may be greater if it invests in derivatives than if it invests only inconventional securities. The use of derivative instruments involves risks different from, and possibly greater than,the risks associated with investing directly in equity or fixed income securities, currencies or other instruments.Derivatives are subject to a number of risks such as leveraging risk, liquidity risk, market risk, credit risk, defaultrisk, counterparty risk (the risk that the other party in an agreement will fail to perform its obligations) andmanagement risk. They also involve the risk of mispricing or improper valuation and the risk that changes in thevalue of the derivative instrument may not correlate exactly with the change in the value of the underlying asset,rate or index.

• Currency Trading Risk. Currency trading strategies may involve instruments that have volatile prices, are illiquidor create economic leverage. Forward currency contracts are subject to the risk that, should forward pricesincrease, a loss will be incurred to the extent that the price of the currency agreed to be purchased exceeds theprice of the currency agreed to be sold.

• Liquidity Risk. The market for certain investments may become illiquid under adverse or volatile market oreconomic conditions, making those investments difficult to sell. The market price of certain investments may falldramatically if there is no liquid trading market.

• Illiquid Securities. An illiquid security may be difficult to sell quickly and at a fair price, which could cause theFund to realize a loss on the security if it was sold at a lower price than that at which it had been valued.

• Counterparty Risk. Counterparty risk is the risk that the other party or parties to an agreement or a participant to atransaction, such as a broker, might default on a contract or fail to perform by failing to pay amounts due orfailing to fulfill the obligations of the contract or transaction.

• High Portfolio Turnover Risk. The Fund will likely engage in active and frequent trading, which may result inhigher portfolio turnover rates, higher transaction costs and realization of short-term capital gains that willgenerally be taxable to shareholders as ordinary income.

• Large Redemptions. The Fund is used as an investment for certain funds of funds and in asset allocation programsand may have a large percentage of its Shares owned by such funds or held in such programs. Large redemptionactivity could result in the Fund incurring additional costs and being forced to sell portfolio securities at a loss tomeet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actionsdesigned to support the markets. Such events and conditions may adversely affect the value of the Fund’ssecurities, result in greater market or liquidity risk or cause difficulty valuing the Fund’s portfolio instruments orachieving the Fund’s objective.

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Please refer to the “Risks” section in the Fund’s Prospectus for further information.

Performance

The following bar chart illustrates the risks of investing in the Fund by showing how the performance of the Fundvaries from year to year. The highest and lowest returns for a full quarter during the periods shown in the bar chart areset forth next to the bar chart. The performance results shown in this section do not reflect any Insurance CompanySeparate Account or Policy charges. Those charges, if included, would have reduced the performance results shown in thissection.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with the index returns that measure broad marketperformance.

Past performance is no indication of future results.

Calendar Year Total Returns

-5.00%

0.00%

5.00%

10.00%

15.00%

20.00%

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

7.24%

(3.57)%

15.81%

10.02%

4.68%

8.38%

(1.45)%

5.45%

(0.14)%

3.10%

Highest Quarterly Return:7.05% (3Q/09)

Lowest Quarterly Return:(3.63)% (3Q/08)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years 10 Years

Strategic Bond Fund. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.10% 3.01% 4.81%Bloomberg Barclays U.S. Aggregate Bond Index (reflects no deduction for fees,expenses or taxes)* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.65% 2.23% 4.34%

* The Bloomberg Barclays U.S. Aggregate Bond Index was formerly known as the Barclays U.S. Aggregate Bond Index.

Management

Investment Adviser

The Fund’s investment adviser is RIM. The Fund’s money managers are:

• Colchester Global Investors Limited • Schroder Investment Management North America Inc.• Logan Circle Partners, L.P. • Scout Investments, Inc.• Pareto Investment Management Limited • Western Asset Management Company and Western

Asset Management Company Limited

Portfolio Manager

Keith Brakebill, a Senior Portfolio Manager, has primary responsibility for the management of the Fund. Mr.Brakebill has managed the Fund since August 2011.

Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premium

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payments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell InvestmentFunds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for moreinformation on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for FundShares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receivecompensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest byinfluencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

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SUMMARY PROSPECTUS

LifePoints®

Funds Variable Target Portfolio Series

MODERATE STRATEGY FUND

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFGX

Investment Objective

The Fund seeks to provide current income and moderate long term capital appreciation.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)#

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.11%Acquired (Underlying) Fund Fees and Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.72%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.03%Less Fee Waivers and Expense Reimbursements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (0.17)%Net Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.86%

# “Total Annual Fund Operating Expenses” and “Net Annual Fund Operating Expenses” have been restated to reflect the proportionate share of theexpenses of the Underlying Funds in which the Fund invests.Until April 30, 2018, RIM has contractually agreed to waive up to the full amount of its 0.20% advisory fee and then to reimburse the Fund forother direct Fund-level expenses to the extent that direct Fund-level expenses exceed 0.14% of the average daily net assets of the Fund on anannual basis. Direct Fund-level expenses do not include extraordinary expenses or the expenses of other investment companies in which the Fundinvests, including the Underlying Funds, which are borne indirectly by the Fund. This waiver and reimbursement may not be terminated duringthe relevant period except with Board approval.

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Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same (taking into account fee waivers/reimbursements in year 1 only). This example doesnot reflect any Insurance Company Separate Account or Policy charges. If it did, the costs shown would have beenhigher. Although your actual costs may be higher or lower, under these assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$88 $311 $553 $1,245

Portfolio Turnover

The Fund pays no transaction costs or commissions when it buys and sells Shares of the Underlying Funds. TheUnderlying Funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” theirportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs affect the Underlying Funds’performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 38% of the average value of itsportfolio. Portfolio turnover rates for the Underlying Funds are available in the Prospectus for the Underlying Funds.

Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund is a “fund of funds,” which seeks to achieve its objective by investing principally in a combination ofseveral other Russell Investment Funds (“RIF”) funds or Russell Investment Company (“RIC”) funds (the “UnderlyingFunds”). RIC is a registered investment company that has the same investment adviser as RIF. Russell InvestmentManagement, LLC (“RIM”), the Fund’s investment adviser, intends the Fund’s strategy of investing in a combination ofUnderlying Funds to result in investment diversification that an investor could otherwise achieve only by holdingnumerous individual investments. The Fund’s approximate target strategic allocation as of May 1, 2017 is 29.5% toequity, 53% to fixed income, 10% to multi-asset and 7.5% to alternative asset classes. As a result of its investments in theUnderlying Funds, the Fund indirectly invests principally in U.S. and non-U.S. equity and fixed income securities andderivatives. Alternative Underlying Funds pursue investment strategies that differ from those of traditional broad marketequity or fixed income funds. The Underlying Funds employ a multi-manager approach whereby most assets of theUnderlying Funds are allocated to different unaffiliated money managers. RIM considers this Fund to be a “moderate”fund due to its investment objective and asset allocation to fixed income and equity Underlying Funds. In addition toinvesting in the Underlying Funds, RIM may seek to actively manage the Fund’s overall exposures (such as asset class,currency, capitalization size, industry, sector, region, credit exposure, country risk, yield curve positioning or interest rates)by investing in derivatives, including futures, options, forwards and swaps, that RIM believes will achieve the desiredrisk/return profile for the Fund. The Fund may hold cash in connection with these investments. The Fund usually, but notalways, pursues a strategy of being fully invested by exposing its cash to the performance of segments of the globalequity market by purchasing index futures contracts (also known as “equitization”).

RIM may modify the target allocation for any Fund, including changes to the Underlying Funds in which a Fundinvests, from time to time. RIM’s allocation decisions are generally based on RIM’s outlook on the business andeconomic cycle, relative market valuations and market sentiment. A Fund’s actual allocation may vary from the targetstrategic asset allocation at any point in time (1) due to market movements, (2) by up to +/- 5% at the equity, fixedincome, multi-asset or alternative category level based on RIM’s capital markets research, and/or (3) due to theimplementation over a period of time of a change to the target strategic asset allocation including the addition of a newUnderlying Fund. There may be no changes in the asset allocation or to the Underlying Funds in a given year or suchchanges may be made one or more times in a year. The Fund’s target strategic asset allocation, range of variance from thetarget strategic asset allocation and the Underlying Funds in which the Fund may invest may be changed from time totime without shareholder notice or approval.

Please refer to the “Investment Objective and Investment Strategies” section in the Fund’s Prospectus for furtherinformation.

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Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Investing in Affiliated Underlying Funds. The assets of the Fund are invested principally in Shares of theUnderlying Funds, and the investment performance of the Fund is directly related to the investment performanceof the Underlying Funds in which it invests. RIM is the investment adviser for both the Fund and the UnderlyingFunds and may be deemed to have a conflict of interest in determining the allocation of the Fund to theUnderlying Funds.

• Asset Allocation. Neither the Fund nor RIM can offer any assurance that the asset allocation of the Fund willeither maximize returns or minimize risks. Nor can the Fund or RIM offer assurance that a recommendedallocation will be the appropriate allocation in all circumstances for every investor. The value of your investmentmay decrease if RIM’s judgment about the attractiveness, value or market trends affecting a particular asset class,investment style or Underlying Fund is incorrect. Asset allocation decisions might also result in the Fund havingmore exposure, indirectly through its investments in the Underlying Funds, to asset classes, countries or regions, orindustries or groups of industries that underperform.

The Fund is exposed to the same risks as the Underlying Funds in direct proportion to the allocation of its assetsamong the Underlying Funds. The following are the principal risks associated with investing in the Underlying Funds,which are also principal risks of investing in the Fund as a result of its investment in the Underlying Funds. In addition,certain principal risks associated with investing in the Underlying Funds and, indirectly, the Fund are also principal risksassociated with investing in the Fund due to RIM’s active management of the Fund’s overall exposures to seek to achievethe desired risk/return profile for the Fund.

• Active Management. Despite strategies designed to achieve the Fund’s and/or an Underlying Fund’s investmentobjective, the value of investments will change with market conditions, and so will the value of any investment inthe Fund and/or Underlying Funds and you could lose money. The securities selected for the Fund’s and/or anUnderlying Fund’s portfolio may not perform as RIM or the Underlying Fund’s money managers expectAdditionally, securities selected may cause the Fund and/or an Underlying Fund to underperform relative to otherfunds with similar investment objectives and strategies. There is no guarantee that RIM will effectively assess theFund’s and/or an Underlying Fund’s portfolio characteristics and it is possible that its judgments regarding theFund’s and/or an Underlying Fund’s risk/return profile may prove incorrect. In addition, actions taken to activelymanage overall Fund and/or Underlying Fund exposures, including risk, may be ineffective and/or cause the Fundand/or Underlying Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

• Index-Based Investing. Index-based strategies, which may be used to actively manage a Fund’s and/or anUnderlying Fund’s overall exposures, may cause the Fund’s and/or an Underlying Fund’s returns to be lower thanif the Fund and/or an Underlying Fund employed a fundamental investment approach to security selection withrespect to that portion of its portfolio. Additionally, index-based strategies are subject to “tracking error” risk,which is the risk that the performance of the portion of the Fund’s and/or an Underlying Fund’s portfolio utilizingan index-based strategy will differ from the performance of the index it seeks to track.

• Non-Discretionary Implementation Risk. With respect to the portion of an Underlying Fund that is managedpursuant to model portfolios provided by non-discretionary money managers, it is expected that trades will beeffected on a periodic basis and therefore less frequently than would typically be the case if discretionary moneymanagers were employed. Given that values of investments change with market conditions, this could cause anUnderlying Fund’s return to be lower than if the Underlying Fund employed discretionary money managers withrespect to that portion of its portfolio.

• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s and/or an Underlying Fund’s overall exposures.Securities selected using quantitative analysis may perform differently than analysis of their historical trends wouldsuggest. Inputs or models may be flawed or not work as anticipated and may cause the Fund and/or an UnderlyingFund to underperform other funds with similar investment objectives and strategies.

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• Equity Securities. The value of equity securities will rise and fall in response to the activities of the company thatissued them, general market conditions and/or economic conditions. Investments in small and mediumcapitalization companies may involve greater risks because these companies generally have narrower markets,more limited managerial and financial resources and a less diversified product offering than larger, moreestablished companies. Small and some medium capitalization stocks may also be thinly traded, and thus, difficultto buy and sell in the market. Investments in preferred stocks are subject to the risks of common stocks, as well asthe risk that interest rates will rise and make the fixed dividend feature, if any, less appealing to investors resultingin a decline in price. In rising markets, defensive stocks are likely to underperform growth, value and dynamicstocks and the relative performance of stocks selected pursuant to a defensive style may fluctuate over time.Dynamic stocks have higher than average stock price volatility and may experience sharp declines in value.

• Convertible Securities. Convertible securities are subject to both the credit and interest rate risks associated withfixed income securities and to the market risk associated with common stock. Contingent convertible securitiesgenerally provide for mandatory conversion into common stock of the issuer under certain circumstances, andtherefore are subject to the risk an Underlying Fund could experience a reduced income rate and a worsenedstanding in the case of an issuer’s insolvency.

• Fixed Income Securities. Prices of fixed income securities generally rise and fall in response to, among otherthings, interest rate changes. Volatility in interest rates and in fixed income markets may increase the risk that anUnderlying Fund’s investments in fixed income securities could lose money. In addition, an Underlying Fund couldlose money if the issuer or guarantor of a fixed income security or other issuer of credit support is unable orunwilling to make timely principal and/or interest payments, or to otherwise honor its obligations. Fixed incomesecurities may be downgraded in credit rating or go into default.

• Non-Investment Grade Debt Securities (“High Yield” or “Junk Bonds”). Non-investment grade debt securitiesinvolve higher volatility and higher risk of default than investment grade bonds.

• U.S. and Non-U.S. Corporate Debt Securities Risk. Investments in U.S. and non-U.S. corporate debt securities aresubject to interest rate risk and market risk, and are affected by perceptions of the creditworthiness and businessprospects of individual issuers. Non-U.S. corporate debt securities may expose an Underlying Fund to greater riskthan investments in U.S. corporate debt securities.

• Government Issued or Guaranteed Securities, U.S. Government Securities. Bonds issued or guaranteed by agovernment are subject to inflation risk, price depreciation risk and default risk.

• Money Market Securities (Including Commercial Paper). Prices of money market securities generally rise and fallin response to interest rate changes.

• Asset-Backed Commercial Paper. Investment in asset-backed commercial paper is subject to the risk thatinsufficient proceeds from the projected cash flows of the contributed receivables are available to repay thecommercial paper.

• Variable and Floating Rate Securities Risk. Variable and floating rate securities generally are less sensitive tointerest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interestrates in general.

• Mortgage-Backed Securities. Mortgage-backed securities may be affected by, among other things, changes orperceived changes in interest rates, factors concerning the interests in and structure of the issuer or the originatorof the mortgage, or the quality of the underlying assets. The underlying assets may default or decline in quality orvalue.

• Asset-Backed Securities. Payment of principal and interest on asset-backed securities may be largely dependentupon the cash flows generated by the assets backing the securities and asset-backed securities may not have thebenefit of any security interest in the related assets.

• Repurchase Agreements. Repurchase agreements are subject to the risk that the sellers may not be able to pay theagreed-upon repurchase price on the repurchase date.

• Puts, Stand-by Commitments and Demand Notes. The ability of an Underlying Fund to exercise a put or stand-bycommitment may depend on the seller’s ability to purchase the securities at the time the put or stand-bycommitment is exercised or on certain restrictions in the buy back arrangement. If there is a shortfall in theanticipated proceeds from demand notes, including variable rate demand notes, the notes may not be fully repaidand an Underlying Fund may lose money.

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• Loans and Other Direct Indebtedness. Loans and other direct indebtedness involve the risk that payment ofprincipal, interest and other amounts due in connection with these investments may not be received. The highlyleveraged nature of many such loans, including bank loans, and other direct indebtedness may make such loansand other direct indebtedness especially vulnerable to adverse changes in economic or market conditions and/orchanges in the financial condition of the debtor. Investments in bank loans are typically subject to the risks offloating rate securities.

• Non-U.S. and Emerging Markets Securities. Non-U.S. securities have risks relating to political, economic andregulatory conditions in foreign countries. The risks associated with non-U.S. securities may be amplified foremerging markets securities.

• Yankee Bonds and Yankee CDs. Issuers of Yankee Bonds and Yankee CDs are not necessarily subject to the sameregulatory requirements that apply to U.S. corporations and banks.

• Currency Risk. Non-U.S. securities that trade in, and receive revenues in, non-U.S. currencies are subject to therisk that those currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, thatthe U.S. dollar will decline in value relative to the currency being hedged. As a result, investments in non-U.S.dollar-denominated securities and currencies may reduce the returns of the Fund and/or an Underlying Fund.

• Synthetic Foreign Equity/Fixed Income Securities. Investments in these instruments involve the risk that the issuerof the instrument may default on its obligation to deliver the underlying security or its value. These instrumentsmay also be subject to liquidity risk, foreign risk and currency risk. In addition, the exercise or settlement datemay be affected by certain market disruption events which could cause the local access products to becomeworthless if the events continue for a period of time.

• Currency Trading Risk. Currency trading strategies may involve instruments that have volatile prices, are illiquidor create economic leverage. Forward currency contracts are subject to the risk that, should forward pricesincrease, a loss will be incurred to the extent that the price of the currency agreed to be purchased exceeds theprice of the currency agreed to be sold.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s and/or an Underlying Fund’s losses may be greater if it invests in derivativesthan if it invests only in conventional securities. The use of derivative instruments involves risks different from,and possibly greater than, the risks associated with investing directly in equity or fixed income securities,currencies or other instruments. Derivatives are subject to a number of risks such as leveraging risk, liquidity risk,market risk, credit risk, default risk, counterparty risk (the risk that the other party in an agreement will fail toperform its obligations) and management risk. They also involve the risk of mispricing or improper valuation andthe risk that changes in the value of the derivative instrument may not correlate exactly with the change in thevalue of the underlying asset, rate or index.

• Counterparty Risk. Counterparty risk is the risk that the other party or parties to an agreement or a participant to atransaction, such as a broker, might default on a contract or fail to perform by failing to pay amounts due orfailing to fulfill the obligations of the contract or transaction.

• Short Sales Risk. A short sale will result in a loss if the price of the security sold short increases between the dateof the short sale and the date on which the borrowed security must be returned. Short sales may give rise to aform of leverage. Leverage tends to exaggerate the effect of any increase or decrease in the value of portfoliosecurities. Short sales have the potential for unlimited loss.

• Securities of Other Investment Companies. Investments in other investment companies expose shareholders to theexpenses and risks associated with the investments of an Underlying Fund as well as to the expenses and risks ofthe underlying investment companies.

• Real Estate Securities. Just as real estate values go up and down, the value of the securities of companies involvedin the industry also fluctuates. Real estate securities, including real estate investment trusts (“REITs”), may beaffected by changes in the value of the underlying properties owned by the companies and by the quality oftenants’ credit.

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• Depositary Receipts. Depositary receipts (including American Depositary Receipts and Global Depositary Receipts)are securities traded on a local stock exchange that represent securities issued by a foreign publicly-listed company.Depositary receipts are generally subject to the same risks of investing in the foreign securities they evidence orinto which they may be converted.

• Commodity Risk. Exposure to the commodities markets may subject an Underlying Fund to greater volatility thaninvestments in traditional securities, particularly if the investments involve leverage. The value ofcommodity-linked derivative instruments may be affected by changes in overall market movements, commodityindex volatility, changes in interest rates or factors affecting a particular industry or commodity and internationaleconomic, political and regulatory developments. The use of leveraged commodity-linked derivatives creates anopportunity for increased return, but also creates the possibility for a greater loss.

• Bank Obligations. The banking industry may be particularly susceptible to certain economic factors such as interestrate changes, adverse developments in the real estate market, fiscal and monetary policy and general economiccycles. The banking industry may also be impacted by legal and regulatory developments.

• Infrastructure Companies. Infrastructure companies are subject to the risk that: the potential for realized revenuevolumes is significantly lower than projected and/or cost overruns; the nature of the concession fundamentallychanges during the life of the project (e.g., the state sponsor alters the terms); macroeconomic factors such as lowGDP growth or high nominal interest rates raise the average cost of funding; government regulation may affectrates charged to customers; government budgetary constraints impact projects; special tariffs are imposed; andchanges in tax laws, regulatory policies or accounting standards could be unfavorable. Other risks includeenvironmental damage due to a company’s operations or an accident, changes in market sentiment towardsinfrastructure and terrorist acts.

• Master Limited Partnerships (“MLPs”). Investing in MLPs involves certain risks related to investing in theunderlying assets of the MLPs and risks associated with pooled investment vehicles. MLPs that concentrate in aparticular industry or a particular geographic region are subject to risks associated with such industry or region.The benefit derived from an Underlying Fund’s investment in MLPs is largely dependent on the MLPs beingtreated as partnerships for federal income tax purposes.

• Illiquid Securities. An illiquid security may be difficult to sell quickly and at a fair price, which could cause anUnderlying Fund to realize a loss on the security if it was sold at a lower price than that at which it had beenvalued.

• Liquidity Risk. The market for certain investments may become illiquid under adverse or volatile market oreconomic conditions, making those investments difficult to sell. The market price of certain investments may falldramatically if there is no liquid trading market.

• Large Redemptions. Certain Underlying Funds are used as investments for certain funds of funds and in assetallocation programs and may have a large percentage of their Shares owned by such funds or held in suchprograms. Large redemption activity could result in an Underlying Fund incurring additional costs and beingforced to sell portfolio securities at a loss to meet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actionsdesigned to support the markets. Such events and conditions may adversely affect the value of the Fund’s and/oran Underlying Fund’s securities, result in greater market or liquidity risk or cause difficulty valuing the Fund’sand/or an Underlying Fund’s portfolio instruments or achieving the Fund’s and/or an Underlying Fund’s objective.

The officers and Trustees of the Fund currently serve as officers and Trustees of the Underlying Funds. RIMcurrently serves as investment manager of the Fund and Underlying Funds. Therefore, conflicts may arise as thosepersons and RIM fulfill their fiduciary responsibilities to the Fund and to the Underlying Funds.

Please refer to the “Risks” section in the Fund’s Prospectus for further information.

Performance

The following bar chart illustrates the risks of investing in the Fund by showing the performance of the Fund sincethe beginning of the Fund’s operation. The highest and lowest returns for a full quarter during the periods shown in the

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bar chart are set forth next to the bar chart. The performance results shown in this section do not reflect any InsuranceCompany Separate Account or Policy charges. Those charges, if included, would have reduced the performance resultsshown in this section.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with index returns that measure broad marketperformance. The Fund is a fund of funds that invests in a variety of asset classes. Therefore, no single index provides anappropriate basis for comparison. For reference purposes, the indexes presented in the chart below have characteristicsthat represent the largest of these asset classes.

Past performance is no indication of future results.

Calendar Year Total Returns

-20.00%

-10.00%

0.00%

10.00%

20.00%

30.00%

2008

2009

2010

2011

2012

2013

2014

2015

2016

(19.97)%

22.45%

12.62%

0.12%

11.07%6.79% 4.85%

(1.71)%

7.75%

Highest Quarterly Return:11.79% (2Q/09)

Lowest Quarterly Return:(9.38)% (4Q/08)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years Since Inception*

Moderate Strategy Fund . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.75% 5.66% 4.33%Bloomberg Barclays U.S. Aggregate Bond Index (reflects no deduction forfees, expenses or taxes)** . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.65% 2.23% 4.28%Russell 1000® Index (reflects no deduction for fees, expenses or taxes) . . . . . . . 12.05% 14.69% 6.74%

* The Fund first issued Shares on May 1, 2007.** The Bloomberg Barclays U.S. Aggregate Bond Index was formerly known as the Barclays U.S. Aggregate Bond Index.

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to theRussell Indexes. Russell

®

is a trademark of Frank Russell Company.

Management

Investment Adviser

RIM is the investment adviser of the Fund and the Underlying Funds.

Portfolio Managers

Rob Balkema, a Senior Portfolio Manager, and Brian Meath, Chief Investment Officer of Multi-Asset Solutions, haveprimary responsibility for the management of the Fund. Mr. Balkema and Mr. Meath have managed the Fund sinceDecember 2014.

Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premiumpayments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell InvestmentFunds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for more

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information on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for FundShares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receivecompensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest byinfluencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

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SUMMARY PROSPECTUS

LifePoints®

Funds Variable Target Portfolio Series

BALANCED STRATEGY FUND

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFHX

Investment Objective

The Fund seeks to provide above average long term capital appreciation and a moderate level of current income.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)#

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.09%Acquired (Underlying) Fund Fees and Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.84%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.13%Less Fee Waivers and Expense Reimbursements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (0.15)%Net Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.98%

# “Total Annual Fund Operating Expenses” and “Net Annual Fund Operating Expenses” have been restated to reflect the proportionate share of theexpenses of the Underlying Funds in which the Fund invests.Until April 30, 2018, RIM has contractually agreed to waive up to the full amount of its 0.20% advisory fee and then to reimburse the Fund forother direct Fund-level expenses to the extent that direct Fund-level expenses exceed 0.14% of the average daily net assets of the Fund on anannual basis. Direct Fund-level expenses do not include extraordinary expenses or the expenses of other investment companies in which the Fundinvests, including the Underlying Funds, which are borne indirectly by the Fund. This waiver and reimbursement may not be terminated duringthe relevant period except with Board approval.

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Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same (taking into account fee waivers/reimbursements in year 1 only). This example doesnot reflect any Insurance Company Separate Account or Policy charges. If it did, the costs shown would have beenhigher. Although your actual costs may be higher or lower, under these assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$100 $344 $608 $1,362

Portfolio Turnover

The Fund pays no transaction costs or commissions when it buys and sells Shares of the Underlying Funds. TheUnderlying Funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” theirportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs affect the Underlying Funds’performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 19% of the average value of itsportfolio. Portfolio turnover rates for the Underlying Funds are available in the Prospectus for the Underlying Funds.

Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund is a “fund of funds,” which seeks to achieve its objective by investing principally in a combination ofseveral other Russell Investment Funds (“RIF”) funds or Russell Investment Company (“RIC”) funds (the “UnderlyingFunds”). RIC is a registered investment company that has the same investment adviser as RIF. Russell InvestmentManagement, LLC (“RIM”), the Fund’s investment adviser, intends the Fund’s strategy of investing in a combination ofUnderlying Funds to result in investment diversification that an investor could otherwise achieve only by holdingnumerous individual investments. The Fund’s approximate target strategic allocation as of May 1, 2017 is 51% to equity,38% to fixed income, 4% to multi-asset and 7% to alternative asset classes. As a result of its investments in theUnderlying Funds, the Fund indirectly invests principally in U.S. and non-U.S. equity and fixed income securities andderivatives. Alternative Underlying Funds pursue investment strategies that differ from those of traditional broad marketequity or fixed income funds. The Underlying Funds employ a multi-manager approach whereby most assets of theUnderlying Funds are allocated to different unaffiliated money managers. RIM considers this Fund to be a “balanced”fund due to its investment objective and asset allocation to equity and fixed income Underlying Funds. In addition toinvesting in the Underlying Funds, RIM may seek to actively manage the Fund’s overall exposures (such as asset class,currency, capitalization size, industry, sector, region, credit exposure, country risk, yield curve positioning or interest rates)by investing in derivatives, including futures, options, forwards and swaps, that RIM believes will achieve the desiredrisk/return profile for the Fund. The Fund may hold cash in connection with these investments. The Fund usually, but notalways, pursues a strategy of being fully invested by exposing its cash to the performance of segments of the globalequity market by purchasing index futures contracts (also known as “equitization”).

RIM may modify the target allocation for any Fund, including changes to the Underlying Funds in which a Fundinvests, from time to time. RIM’s allocation decisions are generally based on RIM’s outlook on the business andeconomic cycle, relative market valuations and market sentiment. A Fund’s actual allocation may vary from the targetstrategic asset allocation at any point in time (1) due to market movements, (2) by up to +/- 5% at the equity, fixedincome, multi-asset or alternative category level based on RIM’s capital markets research, and/or (3) due to theimplementation over a period of time of a change to the target strategic asset allocation including the addition of a newUnderlying Fund. There may be no changes in the asset allocation or to the Underlying Funds in a given year or suchchanges may be made one or more times in a year. The Fund’s target strategic asset allocation, range of variance from thetarget strategic asset allocation and the Underlying Funds in which the Fund may invest may be changed from time totime without shareholder notice or approval.

Please refer to the “Investment Objective and Investment Strategies” section in the Fund’s Prospectus for furtherinformation.

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Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Investing in Affiliated Underlying Funds. The assets of the Fund are invested principally in Shares of theUnderlying Funds, and the investment performance of the Fund is directly related to the investment performanceof the Underlying Funds in which it invests. RIM is the investment adviser for both the Fund and the UnderlyingFunds and may be deemed to have a conflict of interest in determining the allocation of the Fund to theUnderlying Funds.

• Asset Allocation. Neither the Fund nor RIM can offer any assurance that the asset allocation of the Fund willeither maximize returns or minimize risks. Nor can the Fund or RIM offer assurance that a recommendedallocation will be the appropriate allocation in all circumstances for every investor. The value of your investmentmay decrease if RIM’s judgment about the attractiveness, value or market trends affecting a particular asset class,investment style or Underlying Fund is incorrect. Asset allocation decisions might also result in the Fund havingmore exposure, indirectly through its investments in the Underlying Funds, to asset classes, countries or regions, orindustries or groups of industries that underperform.

The Fund is exposed to the same risks as the Underlying Funds in direct proportion to the allocation of its assetsamong the Underlying Funds. The following are the principal risks associated with investing in the Underlying Funds,which are also principal risks of investing in the Fund as a result of its investment in the Underlying Funds. In addition,certain principal risks associated with investing in the Underlying Funds and, indirectly, the Fund are also principal risksassociated with investing in the Fund due to RIM’s active management of the Fund’s overall exposures to seek to achievethe desired risk/return profile for the Fund.

• Active Management. Despite strategies designed to achieve the Fund’s and/or an Underlying Fund’s investmentobjective, the value of investments will change with market conditions, and so will the value of any investment inthe Fund and/or Underlying Funds and you could lose money. The securities selected for the Fund’s and/or anUnderlying Fund’s portfolio may not perform as RIM or the Underlying Fund’s money managers expectAdditionally, securities selected may cause the Fund and/or an Underlying Fund to underperform relative to otherfunds with similar investment objectives and strategies. There is no guarantee that RIM will effectively assess theFund’s and/or an Underlying Fund’s portfolio characteristics and it is possible that its judgments regarding theFund’s and/or an Underlying Fund’s risk/return profile may prove incorrect. In addition, actions taken to activelymanage overall Fund and/or Underlying Fund exposures, including risk, may be ineffective and/or cause the Fundand/or Underlying Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

• Index-Based Investing. Index-based strategies, which may be used to actively manage a Fund’s and/or anUnderlying Fund’s overall exposures, may cause the Fund’s and/or an Underlying Fund’s returns to be lower thanif the Fund and/or an Underlying Fund employed a fundamental investment approach to security selection withrespect to that portion of its portfolio. Additionally, index-based strategies are subject to “tracking error” risk,which is the risk that the performance of the portion of the Fund’s and/or an Underlying Fund’s portfolio utilizingan index-based strategy will differ from the performance of the index it seeks to track.

• Non-Discretionary Implementation Risk. With respect to the portion of an Underlying Fund that is managedpursuant to model portfolios provided by non-discretionary money managers, it is expected that trades will beeffected on a periodic basis and therefore less frequently than would typically be the case if discretionary moneymanagers were employed. Given that values of investments change with market conditions, this could cause anUnderlying Fund’s return to be lower than if the Underlying Fund employed discretionary money managers withrespect to that portion of its portfolio.

• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s and/or an Underlying Fund’s overall exposures.Securities selected using quantitative analysis may perform differently than analysis of their historical trends wouldsuggest. Inputs or models may be flawed or not work as anticipated and may cause the Fund and/or an UnderlyingFund to underperform other funds with similar investment objectives and strategies.

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• Equity Securities. The value of equity securities will rise and fall in response to the activities of the company thatissued them, general market conditions and/or economic conditions. Investments in small and mediumcapitalization companies may involve greater risks because these companies generally have narrower markets,more limited managerial and financial resources and a less diversified product offering than larger, moreestablished companies. Small and some medium capitalization stocks may also be thinly traded, and thus, difficultto buy and sell in the market. Investments in preferred stocks are subject to the risks of common stocks, as well asthe risk that interest rates will rise and make the fixed dividend feature, if any, less appealing to investors resultingin a decline in price. In rising markets, defensive stocks are likely to underperform growth, value and dynamicstocks and the relative performance of stocks selected pursuant to a defensive style may fluctuate over time.Dynamic stocks have higher than average stock price volatility and may experience sharp declines in value.

• Convertible Securities. Convertible securities are subject to both the credit and interest rate risks associated withfixed income securities and to the market risk associated with common stock. Contingent convertible securitiesgenerally provide for mandatory conversion into common stock of the issuer under certain circumstances, andtherefore are subject to the risk an Underlying Fund could experience a reduced income rate and a worsenedstanding in the case of an issuer’s insolvency.

• Fixed Income Securities. Prices of fixed income securities generally rise and fall in response to, among otherthings, interest rate changes. Volatility in interest rates and in fixed income markets may increase the risk that anUnderlying Fund’s investments in fixed income securities could lose money. In addition, an Underlying Fund couldlose money if the issuer or guarantor of a fixed income security or other issuer of credit support is unable orunwilling to make timely principal and/or interest payments, or to otherwise honor its obligations. Fixed incomesecurities may be downgraded in credit rating or go into default.

• Non-Investment Grade Debt Securities (“High Yield” or “Junk Bonds”). Non-investment grade debt securitiesinvolve higher volatility and higher risk of default than investment grade bonds.

• U.S. and Non-U.S. Corporate Debt Securities Risk. Investments in U.S. and non-U.S. corporate debt securities aresubject to interest rate risk and market risk, and are affected by perceptions of the creditworthiness and businessprospects of individual issuers. Non-U.S. corporate debt securities may expose an Underlying Fund to greater riskthan investments in U.S. corporate debt securities.

• Government Issued or Guaranteed Securities, U.S. Government Securities. Bonds issued or guaranteed by agovernment are subject to inflation risk, price depreciation risk and default risk.

• Money Market Securities (Including Commercial Paper). Prices of money market securities generally rise and fallin response to interest rate changes.

• Asset-Backed Commercial Paper. Investment in asset-backed commercial paper is subject to the risk thatinsufficient proceeds from the projected cash flows of the contributed receivables are available to repay thecommercial paper.

• Variable and Floating Rate Securities Risk. Variable and floating rate securities generally are less sensitive tointerest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interestrates in general.

• Mortgage-Backed Securities. Mortgage-backed securities may be affected by, among other things, changes orperceived changes in interest rates, factors concerning the interests in and structure of the issuer or the originatorof the mortgage, or the quality of the underlying assets. The underlying assets may default or decline in quality orvalue.

• Asset-Backed Securities. Payment of principal and interest on asset-backed securities may be largely dependentupon the cash flows generated by the assets backing the securities and asset-backed securities may not have thebenefit of any security interest in the related assets.

• Repurchase Agreements. Repurchase agreements are subject to the risk that the sellers may not be able to pay theagreed-upon repurchase price on the repurchase date.

• Puts, Stand-by Commitments and Demand Notes. The ability of an Underlying Fund to exercise a put or stand-bycommitment may depend on the seller’s ability to purchase the securities at the time the put or stand-bycommitment is exercised or on certain restrictions in the buy back arrangement. If there is a shortfall in theanticipated proceeds from demand notes, including variable rate demand notes, the notes may not be fully repaidand an Underlying Fund may lose money.

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• Loans and Other Direct Indebtedness. Loans and other direct indebtedness involve the risk that payment ofprincipal, interest and other amounts due in connection with these investments may not be received. The highlyleveraged nature of many such loans, including bank loans, and other direct indebtedness may make such loansand other direct indebtedness especially vulnerable to adverse changes in economic or market conditions and/orchanges in the financial condition of the debtor. Investments in bank loans are typically subject to the risks offloating rate securities.

• Non-U.S. and Emerging Markets Securities. Non-U.S. securities have risks relating to political, economic andregulatory conditions in foreign countries. The risks associated with non-U.S. securities may be amplified foremerging markets securities.

• Yankee Bonds and Yankee CDs. Issuers of Yankee Bonds and Yankee CDs are not necessarily subject to the sameregulatory requirements that apply to U.S. corporations and banks.

• Currency Risk. Non-U.S. securities that trade in, and receive revenues in, non-U.S. currencies are subject to therisk that those currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, thatthe U.S. dollar will decline in value relative to the currency being hedged. As a result, investments in non-U.S.dollar-denominated securities and currencies may reduce the returns of the Fund and/or an Underlying Fund.

• Synthetic Foreign Equity/Fixed Income Securities. Investments in these instruments involve the risk that the issuerof the instrument may default on its obligation to deliver the underlying security or its value. These instrumentsmay also be subject to liquidity risk, foreign risk and currency risk. In addition, the exercise or settlement datemay be affected by certain market disruption events which could cause the local access products to becomeworthless if the events continue for a period of time.

• Currency Trading Risk. Currency trading strategies may involve instruments that have volatile prices, are illiquidor create economic leverage. Forward currency contracts are subject to the risk that, should forward pricesincrease, a loss will be incurred to the extent that the price of the currency agreed to be purchased exceeds theprice of the currency agreed to be sold.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s and/or an Underlying Fund’s losses may be greater if it invests in derivativesthan if it invests only in conventional securities. The use of derivative instruments involves risks different from,and possibly greater than, the risks associated with investing directly in equity or fixed income securities,currencies or other instruments. Derivatives are subject to a number of risks such as leveraging risk, liquidity risk,market risk, credit risk, default risk, counterparty risk (the risk that the other party in an agreement will fail toperform its obligations) and management risk. They also involve the risk of mispricing or improper valuation andthe risk that changes in the value of the derivative instrument may not correlate exactly with the change in thevalue of the underlying asset, rate or index.

• Counterparty Risk. Counterparty risk is the risk that the other party or parties to an agreement or a participant to atransaction, such as a broker, might default on a contract or fail to perform by failing to pay amounts due orfailing to fulfill the obligations of the contract or transaction.

• Short Sales Risk. A short sale will result in a loss if the price of the security sold short increases between the dateof the short sale and the date on which the borrowed security must be returned. Short sales may give rise to aform of leverage. Leverage tends to exaggerate the effect of any increase or decrease in the value of portfoliosecurities. Short sales have the potential for unlimited loss.

• Securities of Other Investment Companies. Investments in other investment companies expose shareholders to theexpenses and risks associated with the investments of an Underlying Fund as well as to the expenses and risks ofthe underlying investment companies.

• Real Estate Securities. Just as real estate values go up and down, the value of the securities of companies involvedin the industry also fluctuates. Real estate securities, including real estate investment trusts (“REITs”), may beaffected by changes in the value of the underlying properties owned by the companies and by the quality oftenants’ credit.

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• Depositary Receipts. Depositary receipts (including American Depositary Receipts and Global Depositary Receipts)are securities traded on a local stock exchange that represent securities issued by a foreign publicly-listed company.Depositary receipts are generally subject to the same risks of investing in the foreign securities they evidence orinto which they may be converted.

• Commodity Risk. Exposure to the commodities markets may subject an Underlying Fund to greater volatility thaninvestments in traditional securities, particularly if the investments involve leverage. The value ofcommodity-linked derivative instruments may be affected by changes in overall market movements, commodityindex volatility, changes in interest rates or factors affecting a particular industry or commodity and internationaleconomic, political and regulatory developments. The use of leveraged commodity-linked derivatives creates anopportunity for increased return, but also creates the possibility for a greater loss.

• Bank Obligations. The banking industry may be particularly susceptible to certain economic factors such as interestrate changes, adverse developments in the real estate market, fiscal and monetary policy and general economiccycles. The banking industry may also be impacted by legal and regulatory developments.

• Infrastructure Companies. Infrastructure companies are subject to the risk that: the potential for realized revenuevolumes is significantly lower than projected and/or cost overruns; the nature of the concession fundamentallychanges during the life of the project (e.g., the state sponsor alters the terms); macroeconomic factors such as lowGDP growth or high nominal interest rates raise the average cost of funding; government regulation may affectrates charged to customers; government budgetary constraints impact projects; special tariffs are imposed; andchanges in tax laws, regulatory policies or accounting standards could be unfavorable. Other risks includeenvironmental damage due to a company’s operations or an accident, changes in market sentiment towardsinfrastructure and terrorist acts.

• Master Limited Partnerships (“MLPs”). Investing in MLPs involves certain risks related to investing in theunderlying assets of the MLPs and risks associated with pooled investment vehicles. MLPs that concentrate in aparticular industry or a particular geographic region are subject to risks associated with such industry or region.The benefit derived from an Underlying Fund’s investment in MLPs is largely dependent on the MLPs beingtreated as partnerships for federal income tax purposes.

• Illiquid Securities. An illiquid security may be difficult to sell quickly and at a fair price, which could cause anUnderlying Fund to realize a loss on the security if it was sold at a lower price than that at which it had beenvalued.

• Liquidity Risk. The market for certain investments may become illiquid under adverse or volatile market oreconomic conditions, making those investments difficult to sell. The market price of certain investments may falldramatically if there is no liquid trading market.

• Large Redemptions. Certain Underlying Funds are used as investments for certain funds of funds and in assetallocation programs and may have a large percentage of their Shares owned by such funds or held in suchprograms. Large redemption activity could result in an Underlying Fund incurring additional costs and beingforced to sell portfolio securities at a loss to meet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actionsdesigned to support the markets. Such events and conditions may adversely affect the value of the Fund’s and/oran Underlying Fund’s securities, result in greater market or liquidity risk or cause difficulty valuing the Fund’sand/or an Underlying Fund’s portfolio instruments or achieving the Fund’s and/or an Underlying Fund’s objective.

The officers and Trustees of the Fund currently serve as officers and Trustees of the Underlying Funds. RIMcurrently serves as investment manager of the Fund and Underlying Funds. Therefore, conflicts may arise as thosepersons and RIM fulfill their fiduciary responsibilities to the Fund and to the Underlying Funds.

Please refer to the “Risks” section in the Fund’s Prospectus for further information.

Performance

The following bar chart illustrates the risks of investing in the Fund by showing the performance of the Fund sincethe beginning of the Fund’s operation. The highest and lowest returns for a full quarter during the periods shown in the

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bar chart are set forth next to the bar chart. The performance results shown in this section do not reflect any InsuranceCompany Separate Account or Policy charges. Those charges, if included, would have reduced the performance resultsshown in this section.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with index returns that measure broad marketperformance. The Fund is a fund of funds that invests in a variety of asset classes. Therefore, no single index provides anappropriate basis for comparison. For reference purposes, the indexes presented in the chart below have characteristicsthat represent the largest of these asset classes.

Past performance is no indication of future results.

Calendar Year Total Returns

-30.00%

-20.00%

-10.00%

0.00%

10.00%

20.00%

30.00%

40.00%

2008

2009

2010

2011

2012

2013

2014

2015

2016

(27.27)%

25.49%

14.06%

(2.40)%

12.95% 12.43%

4.61%(2.30)%

9.05%

Highest Quarterly Return:14.73% (2Q/09)

Lowest Quarterly Return:(14.31)% (4Q/08)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years Since Inception*

Balanced Strategy Fund. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.05% 7.20% 4.12%Bloomberg Barclays U.S. Aggregate Bond Index (reflects no deduction forfees, expenses or taxes)** . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.65% 2.23% 4.28%Russell 1000® Index (reflects no deduction for fees, expenses or taxes) . . . . . . . 12.05% 14.69% 6.74%Russell Developed ex-U.S. Large Cap Index (net of tax on dividends fromforeign holdings) (reflects no deduction for fees or expenses) . . . . . . . . . . . . . . . 2.42% 6.36% 0.27%

* The Fund first issued Shares on May 1, 2007.** The Bloomberg Barclays U.S. Aggregate Bond Index was formerly known as the Barclays U.S. Aggregate Bond Index.

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to theRussell Indexes. Russell

®

is a trademark of Frank Russell Company.

Management

Investment Adviser

RIM is the investment adviser of the Fund and the Underlying Funds.

Portfolio Managers

Rob Balkema, a Senior Portfolio Manager, and Brian Meath, Chief Investment Officer of Multi-Asset Solutions, haveprimary responsibility for the management of the Fund. Mr. Balkema and Mr. Meath have managed the Fund sinceDecember 2014.

Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premiumpayments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell Investment

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Funds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for moreinformation on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for FundShares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receivecompensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest byinfluencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

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SUMMARY PROSPECTUS

LifePoints®

Funds Variable Target Portfolio Series

GROWTH STRATEGY FUND

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFIX

Investment Objective

The Fund seeks to provide high long term capital appreciation, and as a secondary objective, current income.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)#

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.09%Acquired (Underlying) Fund Fees and Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.90%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.19%Less Fee Waivers and Expense Reimbursements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (0.14)%Net Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.05%

# “Total Annual Fund Operating Expenses” and “Net Annual Fund Operating Expenses” have been restated to reflect the proportionate share of theexpenses of the Underlying Funds in which the Fund invests.Until April 30, 2018, RIM has contractually agreed to waive up to the full amount of its 0.20% advisory fee and then to reimburse the Fund forother direct Fund-level expenses to the extent that direct Fund-level expenses exceed 0.15% of the average daily net assets of the Fund on anannual basis. Direct Fund-level expenses do not include extraordinary expenses or the expenses of other investment companies in which the Fundinvests, including the Underlying Funds, which are borne indirectly by the Fund. This waiver and reimbursement may not be terminated duringthe relevant period except with Board approval.

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Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same (taking into account fee waivers/reimbursements in year 1 only). This example doesnot reflect any Insurance Company Separate Account or Policy charges. If it did, the costs shown would have beenhigher. Although your actual costs may be higher or lower, under these assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$107 $364 $641 $1,431

Portfolio Turnover

The Fund pays no transaction costs or commissions when it buys and sells Shares of the Underlying Funds. TheUnderlying Funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” theirportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs affect the Underlying Funds’performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 18% of the average value of itsportfolio. Portfolio turnover rates for the Underlying Funds are available in the Prospectus for the Underlying Funds.

Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund is a “fund of funds,” which seeks to achieve its objective by investing principally in a combination ofseveral other Russell Investment Funds (“RIF”) funds or Russell Investment Company (“RIC”) funds (the “UnderlyingFunds”). RIC is a registered investment company that has the same investment adviser as RIF. Russell InvestmentManagement, LLC (“RIM”), the Fund’s investment adviser, intends the Fund’s strategy of investing in a combination ofUnderlying Funds to result in investment diversification that an investor could otherwise achieve only by holdingnumerous individual investments. The Fund’s approximate target strategic allocation as of May 1, 2017 is 70% to equity,22% to fixed income and 8% to alternative asset classes. As a result of its investments in the Underlying Funds, the Fundindirectly invests principally in U.S. and non-U.S. equity and fixed income securities and derivatives. AlternativeUnderlying Funds pursue investment strategies that differ from those of traditional broad market equity or fixed incomefunds. The Underlying Funds employ a multi-manager approach whereby most assets of the Underlying Funds areallocated to different unaffiliated money managers. RIM considers this Fund to be a “growth” fund due to its investmentobjective and asset allocation to equity and alternative Underlying Funds. In addition to investing in the UnderlyingFunds, RIM may seek to actively manage the Fund’s overall exposures (such as asset class, currency, capitalization size,industry, sector, region, credit exposure, country risk, yield curve positioning or interest rates) by investing in derivatives,including futures, options, forwards and swaps, that RIM believes will achieve the desired risk/return profile for the Fund.The Fund may hold cash in connection with these investments. The Fund usually, but not always, pursues a strategy ofbeing fully invested by exposing its cash to the performance of segments of the global equity market by purchasing indexfutures contracts (also known as “equitization”).

RIM may modify the target allocation for any Fund, including changes to the Underlying Funds in which a Fundinvests, from time to time. RIM’s allocation decisions are generally based on RIM’s outlook on the business andeconomic cycle, relative market valuations and market sentiment. A Fund’s actual allocation may vary from the targetstrategic asset allocation at any point in time (1) due to market movements, (2) by up to +/- 5% at the equity, fixedincome, multi-asset or alternative category level based on RIM’s capital markets research, and/or (3) due to theimplementation over a period of time of a change to the target strategic asset allocation including the addition of a newUnderlying Fund. There may be no changes in the asset allocation or to the Underlying Funds in a given year or suchchanges may be made one or more times in a year. The Fund’s target strategic asset allocation, range of variance from thetarget strategic asset allocation and the Underlying Funds in which the Fund may invest may be changed from time totime without shareholder notice or approval.

Please refer to the “Investment Objective and Investment Strategies” section in the Fund’s Prospectus for furtherinformation.

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Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Investing in Affiliated Underlying Funds. The assets of the Fund are invested principally in Shares of theUnderlying Funds, and the investment performance of the Fund is directly related to the investment performanceof the Underlying Funds in which it invests. RIM is the investment adviser for both the Fund and the UnderlyingFunds and may be deemed to have a conflict of interest in determining the allocation of the Fund to theUnderlying Funds.

• Asset Allocation. Neither the Fund nor RIM can offer any assurance that the asset allocation of the Fund willeither maximize returns or minimize risks. Nor can the Fund or RIM offer assurance that a recommendedallocation will be the appropriate allocation in all circumstances for every investor. The value of your investmentmay decrease if RIM’s judgment about the attractiveness, value or market trends affecting a particular asset class,investment style or Underlying Fund is incorrect. Asset allocation decisions might also result in the Fund havingmore exposure, indirectly through its investments in the Underlying Funds, to asset classes, countries or regions, orindustries or groups of industries that underperform.

The Fund is exposed to the same risks as the Underlying Funds in direct proportion to the allocation of its assetsamong the Underlying Funds. The following are the principal risks associated with investing in the Underlying Funds,which are also principal risks of investing in the Fund as a result of its investment in the Underlying Funds. In addition,certain principal risks associated with investing in the Underlying Funds and, indirectly, the Fund are also principal risksassociated with investing in the Fund due to RIM’s active management of the Fund’s overall exposures to seek to achievethe desired risk/return profile for the Fund.

• Active Management. Despite strategies designed to achieve the Fund’s and/or an Underlying Fund’s investmentobjective, the value of investments will change with market conditions, and so will the value of any investment inthe Fund and/or Underlying Funds and you could lose money. The securities selected for the Fund’s and/or anUnderlying Fund’s portfolio may not perform as RIM or the Underlying Fund’s money managers expectAdditionally, securities selected may cause the Fund and/or an Underlying Fund to underperform relative to otherfunds with similar investment objectives and strategies. There is no guarantee that RIM will effectively assess theFund’s and/or an Underlying Fund’s portfolio characteristics and it is possible that its judgments regarding theFund’s and/or an Underlying Fund’s risk/return profile may prove incorrect. In addition, actions taken to activelymanage overall Fund and/or Underlying Fund exposures, including risk, may be ineffective and/or cause the Fundand/or Underlying Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

• Index-Based Investing. Index-based strategies, which may be used to actively manage a Fund’s and/or anUnderlying Fund’s overall exposures, may cause the Fund’s and/or an Underlying Fund’s returns to be lower thanif the Fund and/or an Underlying Fund employed a fundamental investment approach to security selection withrespect to that portion of its portfolio. Additionally, index-based strategies are subject to “tracking error” risk,which is the risk that the performance of the portion of the Fund’s and/or an Underlying Fund’s portfolio utilizingan index-based strategy will differ from the performance of the index it seeks to track.

• Non-Discretionary Implementation Risk. With respect to the portion of an Underlying Fund that is managedpursuant to model portfolios provided by non-discretionary money managers, it is expected that trades will beeffected on a periodic basis and therefore less frequently than would typically be the case if discretionary moneymanagers were employed. Given that values of investments change with market conditions, this could cause anUnderlying Fund’s return to be lower than if the Underlying Fund employed discretionary money managers withrespect to that portion of its portfolio.

• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s and/or an Underlying Fund’s overall exposures.Securities selected using quantitative analysis may perform differently than analysis of their historical trends wouldsuggest. Inputs or models may be flawed or not work as anticipated and may cause the Fund and/or an UnderlyingFund to underperform other funds with similar investment objectives and strategies.

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• Equity Securities. The value of equity securities will rise and fall in response to the activities of the company thatissued them, general market conditions and/or economic conditions. Investments in small and mediumcapitalization companies may involve greater risks because these companies generally have narrower markets,more limited managerial and financial resources and a less diversified product offering than larger, moreestablished companies. Small and some medium capitalization stocks may also be thinly traded, and thus, difficultto buy and sell in the market. Investments in preferred stocks are subject to the risks of common stocks, as well asthe risk that interest rates will rise and make the fixed dividend feature, if any, less appealing to investors resultingin a decline in price. In rising markets, defensive stocks are likely to underperform growth, value and dynamicstocks and the relative performance of stocks selected pursuant to a defensive style may fluctuate over time.Dynamic stocks have higher than average stock price volatility and may experience sharp declines in value.

• Convertible Securities. Convertible securities are subject to both the credit and interest rate risks associated withfixed income securities and to the market risk associated with common stock. Contingent convertible securitiesgenerally provide for mandatory conversion into common stock of the issuer under certain circumstances, andtherefore are subject to the risk an Underlying Fund could experience a reduced income rate and a worsenedstanding in the case of an issuer’s insolvency.

• Fixed Income Securities. Prices of fixed income securities generally rise and fall in response to, among otherthings, interest rate changes. Volatility in interest rates and in fixed income markets may increase the risk that anUnderlying Fund’s investments in fixed income securities could lose money. In addition, an Underlying Fund couldlose money if the issuer or guarantor of a fixed income security or other issuer of credit support is unable orunwilling to make timely principal and/or interest payments, or to otherwise honor its obligations. Fixed incomesecurities may be downgraded in credit rating or go into default.

• Non-Investment Grade Debt Securities (“High Yield” or “Junk Bonds”). Non-investment grade debt securitiesinvolve higher volatility and higher risk of default than investment grade bonds.

• U.S. and Non-U.S. Corporate Debt Securities Risk. Investments in U.S. and non-U.S. corporate debt securities aresubject to interest rate risk and market risk, and are affected by perceptions of the creditworthiness and businessprospects of individual issuers. Non-U.S. corporate debt securities may expose an Underlying Fund to greater riskthan investments in U.S. corporate debt securities.

• Government Issued or Guaranteed Securities, U.S. Government Securities. Bonds issued or guaranteed by agovernment are subject to inflation risk, price depreciation risk and default risk.

• Money Market Securities (Including Commercial Paper). Prices of money market securities generally rise and fallin response to interest rate changes.

• Asset-Backed Commercial Paper. Investment in asset-backed commercial paper is subject to the risk thatinsufficient proceeds from the projected cash flows of the contributed receivables are available to repay thecommercial paper.

• Variable and Floating Rate Securities Risk. Variable and floating rate securities generally are less sensitive tointerest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interestrates in general.

• Mortgage-Backed Securities. Mortgage-backed securities may be affected by, among other things, changes orperceived changes in interest rates, factors concerning the interests in and structure of the issuer or the originatorof the mortgage, or the quality of the underlying assets. The underlying assets may default or decline in quality orvalue.

• Asset-Backed Securities. Payment of principal and interest on asset-backed securities may be largely dependentupon the cash flows generated by the assets backing the securities and asset-backed securities may not have thebenefit of any security interest in the related assets.

• Repurchase Agreements. Repurchase agreements are subject to the risk that the sellers may not be able to pay theagreed-upon repurchase price on the repurchase date.

• Loans and Other Direct Indebtedness. Loans and other direct indebtedness involve the risk that payment ofprincipal, interest and other amounts due in connection with these investments may not be received. The highlyleveraged nature of many such loans, including bank loans, and other direct indebtedness may make such loans

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and other direct indebtedness especially vulnerable to adverse changes in economic or market conditions and/orchanges in the financial condition of the debtor. Investments in bank loans are typically subject to the risks offloating rate securities.

• Non-U.S. and Emerging Markets Securities. Non-U.S. securities have risks relating to political, economic andregulatory conditions in foreign countries. The risks associated with non-U.S. securities may be amplified foremerging markets securities.

• Yankee Bonds and Yankee CDs. Issuers of Yankee Bonds and Yankee CDs are not necessarily subject to the sameregulatory requirements that apply to U.S. corporations and banks.

• Currency Risk. Non-U.S. securities that trade in, and receive revenues in, non-U.S. currencies are subject to therisk that those currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, thatthe U.S. dollar will decline in value relative to the currency being hedged. As a result, investments in non-U.S.dollar-denominated securities and currencies may reduce the returns of the Fund and/or an Underlying Fund.

• Synthetic Foreign Equity/Fixed Income Securities. Investments in these instruments involve the risk that the issuerof the instrument may default on its obligation to deliver the underlying security or its value. These instrumentsmay also be subject to liquidity risk, foreign risk and currency risk. In addition, the exercise or settlement datemay be affected by certain market disruption events which could cause the local access products to becomeworthless if the events continue for a period of time.

• Currency Trading Risk. Currency trading strategies may involve instruments that have volatile prices, are illiquidor create economic leverage. Forward currency contracts are subject to the risk that, should forward pricesincrease, a loss will be incurred to the extent that the price of the currency agreed to be purchased exceeds theprice of the currency agreed to be sold.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s and/or an Underlying Fund’s losses may be greater if it invests in derivativesthan if it invests only in conventional securities. The use of derivative instruments involves risks different from,and possibly greater than, the risks associated with investing directly in equity or fixed income securities,currencies or other instruments. Derivatives are subject to a number of risks such as leveraging risk, liquidity risk,market risk, credit risk, default risk, counterparty risk (the risk that the other party in an agreement will fail toperform its obligations) and management risk. They also involve the risk of mispricing or improper valuation andthe risk that changes in the value of the derivative instrument may not correlate exactly with the change in thevalue of the underlying asset, rate or index.

• Counterparty Risk. Counterparty risk is the risk that the other party or parties to an agreement or a participant to atransaction, such as a broker, might default on a contract or fail to perform by failing to pay amounts due orfailing to fulfill the obligations of the contract or transaction.

• Short Sales Risk. A short sale will result in a loss if the price of the security sold short increases between the dateof the short sale and the date on which the borrowed security must be returned. Short sales may give rise to aform of leverage. Leverage tends to exaggerate the effect of any increase or decrease in the value of portfoliosecurities. Short sales have the potential for unlimited loss.

• Securities of Other Investment Companies. Investments in other investment companies expose shareholders to theexpenses and risks associated with the investments of an Underlying Fund as well as to the expenses and risks ofthe underlying investment companies.

• Real Estate Securities. Just as real estate values go up and down, the value of the securities of companies involvedin the industry also fluctuates. Real estate securities, including real estate investment trusts (“REITs”), may beaffected by changes in the value of the underlying properties owned by the companies and by the quality oftenants’ credit.

• Depositary Receipts. Depositary receipts (including American Depositary Receipts and Global Depositary Receipts)are securities traded on a local stock exchange that represent securities issued by a foreign publicly-listed company.Depositary receipts are generally subject to the same risks of investing in the foreign securities they evidence orinto which they may be converted.

• Commodity Risk. Exposure to the commodities markets may subject an Underlying Fund to greater volatility thaninvestments in traditional securities, particularly if the investments involve leverage. The value of

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commodity-linked derivative instruments may be affected by changes in overall market movements, commodityindex volatility, changes in interest rates or factors affecting a particular industry or commodity and internationaleconomic, political and regulatory developments. The use of leveraged commodity-linked derivatives creates anopportunity for increased return, but also creates the possibility for a greater loss.

• Bank Obligations. The banking industry may be particularly susceptible to certain economic factors such as interestrate changes, adverse developments in the real estate market, fiscal and monetary policy and general economiccycles. The banking industry may also be impacted by legal and regulatory developments.

• Infrastructure Companies. Infrastructure companies are subject to the risk that: the potential for realized revenuevolumes is significantly lower than projected and/or cost overruns; the nature of the concession fundamentallychanges during the life of the project (e.g., the state sponsor alters the terms); macroeconomic factors such as lowGDP growth or high nominal interest rates raise the average cost of funding; government regulation may affectrates charged to customers; government budgetary constraints impact projects; special tariffs are imposed; andchanges in tax laws, regulatory policies or accounting standards could be unfavorable. Other risks includeenvironmental damage due to a company’s operations or an accident, changes in market sentiment towardsinfrastructure and terrorist acts.

• Master Limited Partnerships (“MLPs”). Investing in MLPs involves certain risks related to investing in theunderlying assets of the MLPs and risks associated with pooled investment vehicles. MLPs that concentrate in aparticular industry or a particular geographic region are subject to risks associated with such industry or region.The benefit derived from an Underlying Fund’s investment in MLPs is largely dependent on the MLPs beingtreated as partnerships for federal income tax purposes.

• Illiquid Securities. An illiquid security may be difficult to sell quickly and at a fair price, which could cause anUnderlying Fund to realize a loss on the security if it was sold at a lower price than that at which it had beenvalued.

• Liquidity Risk. The market for certain investments may become illiquid under adverse or volatile market oreconomic conditions, making those investments difficult to sell. The market price of certain investments may falldramatically if there is no liquid trading market.

• Large Redemptions. Certain Underlying Funds are used as investments for certain funds of funds and in assetallocation programs and may have a large percentage of their Shares owned by such funds or held in suchprograms. Large redemption activity could result in an Underlying Fund incurring additional costs and beingforced to sell portfolio securities at a loss to meet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actionsdesigned to support the markets. Such events and conditions may adversely affect the value of the Fund’s and/oran Underlying Fund’s securities, result in greater market or liquidity risk or cause difficulty valuing the Fund’sand/or an Underlying Fund’s portfolio instruments or achieving the Fund’s and/or an Underlying Fund’s objective.

The officers and Trustees of the Fund currently serve as officers and Trustees of the Underlying Funds. RIMcurrently serves as investment manager of the Fund and Underlying Funds. Therefore, conflicts may arise as thosepersons and RIM fulfill their fiduciary responsibilities to the Fund and to the Underlying Funds.

Please refer to the “Risks” section in the Fund’s Prospectus for further information.

Performance

The following bar chart illustrates the risks of investing in the Fund by showing the performance of the Fund sincethe beginning of the Fund’s operation. The highest and lowest returns for a full quarter during the periods shown in thebar chart are set forth next to the bar chart. The performance results shown in this section do not reflect any InsuranceCompany Separate Account or Policy charges. Those charges, if included, would have reduced the performance resultsshown in this section.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with index returns that measure broad market

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performance. The Fund is a fund of funds that invests in a variety of asset classes. Therefore, no single index provides anappropriate basis for comparison. For reference purposes, the indexes presented in the chart below have characteristicsthat represent the largest of these asset classes.

Past performance is no indication of future results.

Calendar Year Total Returns

-40.00%

-20.00%

0.00%

20.00%

40.00%

2008

2009

2010

2011

2012

2013

2014

2015

2016

(34.30)%

28.59%

15.06%

(4.73)%

14.22% 16.56%

3.76%(3.31)%

9.73%

Highest Quarterly Return:17.69% (2Q/09)

Lowest Quarterly Return:(19.20)% (4Q/08)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years

SinceInception*

Growth Strategy Fund . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.73% 7.94% 3.43%Russell 1000® Index (reflects no deduction for fees, expenses or taxes) . . . . . . . . . . . 12.05% 14.69% 6.74%Bloomberg Barclays U.S. Aggregate Bond Index (reflects no deduction for fees,expenses or taxes)** . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.65% 2.23% 4.28%Russell Developed ex-U.S. Large Cap Index (net of tax on dividends from foreignholdings) (reflects no deduction for fees or expenses). . . . . . . . . . . . . . . . . . . . . . . . . . 2.42% 6.36% 0.27%

* The Fund first issued Shares on May 1, 2007.** The Bloomberg Barclays U.S. Aggregate Bond Index was formerly known as the Barclays U.S. Aggregate Bond Index.

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to theRussell Indexes. Russell

®

is a trademark of Frank Russell Company.

Management

Investment Adviser

RIM is the investment adviser of the Fund and the Underlying Funds.

Portfolio Managers

Rob Balkema, a Senior Portfolio Manager, and Brian Meath, Chief Investment Officer of Multi-Asset Solutions, haveprimary responsibility for the management of the Fund. Mr. Balkema and Mr. Meath have managed the Fund sinceDecember 2014.

Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premiumpayments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell InvestmentFunds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for moreinformation on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

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For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for FundShares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receivecompensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest byinfluencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

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SUMMARY PROSPECTUS

LifePoints®

Funds Variable Target Portfolio Series

EQUITY GROWTH STRATEGY FUND

May 1, 2017

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks.You can find the Fund’s Prospectus, Statement of Additional Information (SAI), Annual Report and other information about theFund online at http://hosted.rightprospectus.com/RIF/. You can also get this information at no cost by calling 1-800-787-7354 or bysending an e-mail to: [email protected]. The Fund’s Prospectus and SAI, both dated May 1, 2017, and the Fund’smost recent shareholder report, dated December 31, 2016, are all incorporated by reference into this Summary Prospectus.

Ticker: RIFJX

Investment Objective

The Fund seeks to provide high long term capital appreciation.

Fees and Expenses of the Fund

The following tables describe the fees and expenses that you may pay if you buy and hold Shares of the Fund. Thefees and expenses shown in this section do not reflect any Insurance Company Separate Account or Policy charges. Thosecharges, if included, would have increased overall fees and expenses. Please refer to your account or policy documentsfor a description of those fees and expenses. Please see the Expense Notes section of the Fund’s Prospectus for furtherinformation regarding expenses of the Fund.

Shareholder Fees (fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of yourinvestment)#

Advisory Fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20%Other Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15%Acquired (Underlying) Fund Fees and Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.96%Total Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.31%Less Fee Waivers and Expense Reimbursements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (0.20)%Net Annual Fund Operating Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11%

# “Total Annual Fund Operating Expenses” and “Net Annual Fund Operating Expenses” have been restated to reflect the proportionate share of theexpenses of the Underlying Funds in which the Fund invests.Until April 30, 2018, RIM has contractually agreed to waive up to the full amount of its 0.20% advisory fee and then to reimburse the Fund forother direct Fund-level expenses to the extent that direct Fund-level expenses exceed 0.15% of the average daily net assets of the Fund on anannual basis. Direct Fund-level expenses do not include extraordinary expenses or the expenses of other investment companies in which the Fundinvests, including the Underlying Funds, which are borne indirectly by the Fund. This waiver and reimbursement may not be terminated duringthe relevant period except with Board approval.

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Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in othermutual funds.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of yourShares at the end of those periods. The example also assumes your investment has a 5% return each year and thatoperating expenses remain the same (taking into account fee waivers/reimbursements in year 1 only). This example doesnot reflect any Insurance Company Separate Account or Policy charges. If it did, the costs shown would have beenhigher. Although your actual costs may be higher or lower, under these assumptions your costs would be:

1 Year 3 Years 5 Years 10 Years

$113 $395 $698 $1,558

Portfolio Turnover

The Fund pays no transaction costs or commissions when it buys and sells Shares of the Underlying Funds. TheUnderlying Funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” theirportfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs affect the Underlying Funds’performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 21% of the average value of itsportfolio. Portfolio turnover rates for the Underlying Funds are available in the Prospectus for the Underlying Funds.

Investments, Risks and Performance

Principal Investment Strategies of the Fund

The Fund is a “fund of funds,” which seeks to achieve its objective by investing principally in a combination ofseveral other Russell Investment Funds (“RIF”) funds or Russell Investment Company (“RIC”) funds (the “UnderlyingFunds”). RIC is a registered investment company that has the same investment adviser as RIF. Russell InvestmentManagement, LLC (“RIM”), the Fund’s investment adviser, intends the Fund’s strategy of investing in a combination ofUnderlying Funds to result in investment diversification that an investor could otherwise achieve only by holdingnumerous individual investments. The Fund’s approximate target strategic allocation as of May 1, 2017 is 85% to equity,7% to fixed income and 8% to alternative asset classes. As a result of its investments in the Underlying Funds, the Fundindirectly invests principally in U.S. and non-U.S. equity and fixed income securities and derivatives. AlternativeUnderlying Funds pursue investment strategies that differ from those of traditional broad market equity or fixed incomefunds. The Underlying Funds employ a multi-manager approach whereby most assets of the Underlying Funds areallocated to different unaffiliated money managers. RIM considers this Fund to be an “equity growth” fund due to itsinvestment objective and asset allocation to equity and alternative Underlying Funds. In addition to investing in theUnderlying Funds, RIM may seek to actively manage the Fund’s overall exposures (such as asset class, currency,capitalization size, industry, sector, region, credit exposure, country risk, yield curve positioning or interest rates) byinvesting in derivatives, including futures, options, forwards and swaps, that RIM believes will achieve the desiredrisk/return profile for the Fund. The Fund may hold cash in connection with these investments. The Fund usually, but notalways, pursues a strategy of being fully invested by exposing its cash to the performance of segments of the globalequity market by purchasing index futures contracts (also known as “equitization”).

RIM may modify the target allocation for any Fund, including changes to the Underlying Funds in which a Fundinvests, from time to time. RIM’s allocation decisions are generally based on RIM’s outlook on the business andeconomic cycle, relative market valuations and market sentiment. A Fund’s actual allocation may vary from the targetstrategic asset allocation at any point in time (1) due to market movements, (2) by up to +/- 5% at the equity, fixedincome, multi-asset or alternative category level based on RIM’s capital markets research, and/or (3) due to theimplementation over a period of time of a change to the target strategic asset allocation including the addition of a newUnderlying Fund. There may be no changes in the asset allocation or to the Underlying Funds in a given year or suchchanges may be made one or more times in a year. The Fund’s target strategic asset allocation, range of variance from thetarget strategic asset allocation and the Underlying Funds in which the Fund may invest may be changed from time totime without shareholder notice or approval. The Fund has a non-fundamental policy to invest, under normalcircumstances, at least 80% of the value of its net assets plus borrowings for investment purposes in shares of equityUnderlying Funds. The Fund considers certain alternative Underlying Funds that invest predominantly in equity securitiesto be equity Underlying Funds for purposes of assessing compliance with this policy.

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Please refer to the “Investment Objective and Investment Strategies” section in the Fund’s Prospectus for furtherinformation.

Principal Risks of Investing in the Fund

An investment in the Fund, like any investment, has risks. The value of the Fund fluctuates and you could losemoney. The principal risks of investing in the Fund are those associated with:

• Investing in Affiliated Underlying Funds. The assets of the Fund are invested principally in Shares of theUnderlying Funds, and the investment performance of the Fund is directly related to the investment performanceof the Underlying Funds in which it invests. RIM is the investment adviser for both the Fund and the UnderlyingFunds and may be deemed to have a conflict of interest in determining the allocation of the Fund to theUnderlying Funds.

• Asset Allocation. Neither the Fund nor RIM can offer any assurance that the asset allocation of the Fund willeither maximize returns or minimize risks. Nor can the Fund or RIM offer assurance that a recommendedallocation will be the appropriate allocation in all circumstances for every investor. The value of your investmentmay decrease if RIM’s judgment about the attractiveness, value or market trends affecting a particular asset class,investment style or Underlying Fund is incorrect. Asset allocation decisions might also result in the Fund havingmore exposure, indirectly through its investments in the Underlying Funds, to asset classes, countries or regions, orindustries or groups of industries that underperform.

The Fund is exposed to the same risks as the Underlying Funds in direct proportion to the allocation of its assetsamong the Underlying Funds. The following are the principal risks associated with investing in the Underlying Funds,which are also principal risks of investing in the Fund as a result of its investment in the Underlying Funds. In addition,certain principal risks associated with investing in the Underlying Funds and, indirectly, the Fund are also principal risksassociated with investing in the Fund due to RIM’s active management of the Fund’s overall exposures to seek to achievethe desired risk/return profile for the Fund.

• Active Management. Despite strategies designed to achieve the Fund’s and/or an Underlying Fund’s investmentobjective, the value of investments will change with market conditions, and so will the value of any investment inthe Fund and/or Underlying Funds and you could lose money. The securities selected for the Fund’s and/or anUnderlying Fund’s portfolio may not perform as RIM or the Underlying Fund’s money managers expectAdditionally, securities selected may cause the Fund and/or an Underlying Fund to underperform relative to otherfunds with similar investment objectives and strategies. There is no guarantee that RIM will effectively assess theFund’s and/or an Underlying Fund’s portfolio characteristics and it is possible that its judgments regarding theFund’s and/or an Underlying Fund’s risk/return profile may prove incorrect. In addition, actions taken to activelymanage overall Fund and/or Underlying Fund exposures, including risk, may be ineffective and/or cause the Fundand/or Underlying Fund to underperform.

• Multi-Manager Approach. While the investment styles employed by the money managers are intended to becomplementary, they may not in fact be complementary. A multi-manager approach could result in more exposureto certain types of securities and higher portfolio turnover.

• Index-Based Investing. Index-based strategies, which may be used to actively manage a Fund’s and/or anUnderlying Fund’s overall exposures, may cause the Fund’s and/or an Underlying Fund’s returns to be lower thanif the Fund and/or an Underlying Fund employed a fundamental investment approach to security selection withrespect to that portion of its portfolio. Additionally, index-based strategies are subject to “tracking error” risk,which is the risk that the performance of the portion of the Fund’s and/or an Underlying Fund’s portfolio utilizingan index-based strategy will differ from the performance of the index it seeks to track.

• Non-Discretionary Implementation Risk. With respect to the portion of an Underlying Fund that is managedpursuant to model portfolios provided by non-discretionary money managers, it is expected that trades will beeffected on a periodic basis and therefore less frequently than would typically be the case if discretionary moneymanagers were employed. Given that values of investments change with market conditions, this could cause anUnderlying Fund’s return to be lower than if the Underlying Fund employed discretionary money managers withrespect to that portion of its portfolio.

• Quantitative Investing. Quantitative inputs and models are generally backward-looking or use historical data toevaluate prospective investments or to generate forecasts which could result in incorrect assessments of the specificportfolio characteristics or ineffective adjustments to the Fund’s and/or an Underlying Fund’s overall exposures.

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Securities selected using quantitative analysis may perform differently than analysis of their historical trends wouldsuggest. Inputs or models may be flawed or not work as anticipated and may cause the Fund and/or an UnderlyingFund to underperform other funds with similar investment objectives and strategies.

• Equity Securities. The value of equity securities will rise and fall in response to the activities of the company thatissued them, general market conditions and/or economic conditions. Investments in small and mediumcapitalization companies may involve greater risks because these companies generally have narrower markets,more limited managerial and financial resources and a less diversified product offering than larger, moreestablished companies. Small and some medium capitalization stocks may also be thinly traded, and thus, difficultto buy and sell in the market. Investments in preferred stocks are subject to the risks of common stocks, as well asthe risk that interest rates will rise and make the fixed dividend feature, if any, less appealing to investors resultingin a decline in price. In rising markets, defensive stocks are likely to underperform growth, value and dynamicstocks and the relative performance of stocks selected pursuant to a defensive style may fluctuate over time.Dynamic stocks have higher than average stock price volatility and may experience sharp declines in value.

• Convertible Securities. Convertible securities are subject to both the credit and interest rate risks associated withfixed income securities and to the market risk associated with common stock. Contingent convertible securitiesgenerally provide for mandatory conversion into common stock of the issuer under certain circumstances, andtherefore are subject to the risk an Underlying Fund could experience a reduced income rate and a worsenedstanding in the case of an issuer’s insolvency.

• Non-U.S. and Emerging Markets Securities. Non-U.S. securities have risks relating to political, economic andregulatory conditions in foreign countries. The risks associated with non-U.S. securities may be amplified foremerging markets securities.

• Fixed Income Securities. Prices of fixed income securities generally rise and fall in response to, among otherthings, interest rate changes. Volatility in interest rates and in fixed income markets may increase the risk that anUnderlying Fund’s investments in fixed income securities could lose money. In addition, an Underlying Fund couldlose money if the issuer or guarantor of a fixed income security or other issuer of credit support is unable orunwilling to make timely principal and/or interest payments, or to otherwise honor its obligations. Fixed incomesecurities may be downgraded in credit rating or go into default.

• Non-Investment Grade Debt Securities (“High Yield” or “Junk Bonds”). Non-investment grade debt securitiesinvolve higher volatility and higher risk of default than investment grade bonds.

• U.S. and Non-U.S. Corporate Debt Securities Risk. Investments in U.S. and non-U.S. corporate debt securities aresubject to interest rate risk and market risk, and are affected by perceptions of the creditworthiness and businessprospects of individual issuers. Non-U.S. corporate debt securities may expose an Underlying Fund to greater riskthan investments in U.S. corporate debt securities.

• Government Issued or Guaranteed Securities, U.S. Government Securities. Bonds issued or guaranteed by agovernment are subject to inflation risk, price depreciation risk and default risk.

• Money Market Securities (Including Commercial Paper). Prices of money market securities generally rise and fallin response to interest rate changes.

• Asset-Backed Commercial Paper. Investment in asset-backed commercial paper is subject to the risk thatinsufficient proceeds from the projected cash flows of the contributed receivables are available to repay thecommercial paper.

• Variable and Floating Rate Securities Risk. Variable and floating rate securities generally are less sensitive tointerest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interestrates in general.

• Loans and Other Direct Indebtedness. Loans and other direct indebtedness involve the risk that payment ofprincipal, interest and other amounts due in connection with these investments may not be received. The highlyleveraged nature of many such loans, including bank loans, and other direct indebtedness may make such loansand other direct indebtedness especially vulnerable to adverse changes in economic or market conditions and/orchanges in the financial condition of the debtor. Investments in bank loans are typically subject to the risks offloating rate securities.

• Yankee Bonds and Yankee CDs. Issuers of Yankee Bonds and Yankee CDs are not necessarily subject to the sameregulatory requirements that apply to U.S. corporations and banks.

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• Currency Risk. Non-U.S. securities that trade in, and receive revenues in, non-U.S. currencies are subject to therisk that those currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, thatthe U.S. dollar will decline in value relative to the currency being hedged. As a result, investments in non-U.S.dollar-denominated securities and currencies may reduce the returns of the Fund and/or an Underlying Fund.

• Synthetic Foreign Equity/Fixed Income Securities. Investments in these instruments involve the risk that the issuerof the instrument may default on its obligation to deliver the underlying security or its value. These instrumentsmay also be subject to liquidity risk, foreign risk and currency risk. In addition, the exercise or settlement datemay be affected by certain market disruption events which could cause the local access products to becomeworthless if the events continue for a period of time.

• Currency Trading Risk. Currency trading strategies may involve instruments that have volatile prices, are illiquidor create economic leverage. Forward currency contracts are subject to the risk that, should forward pricesincrease, a loss will be incurred to the extent that the price of the currency agreed to be purchased exceeds theprice of the currency agreed to be sold.

• Derivatives. Investments in a derivative instrument could lose more than the initial amount invested. Compared toconventional securities, derivatives can be more sensitive to changes in interest rates or to sudden fluctuations inmarket prices and thus the Fund’s and/or an Underlying Fund’s losses may be greater if it invests in derivativesthan if it invests only in conventional securities. The use of derivative instruments involves risks different from,and possibly greater than, the risks associated with investing directly in equity or fixed income securities,currencies or other instruments. Derivatives are subject to a number of risks such as leveraging risk, liquidity risk,market risk, credit risk, default risk, counterparty risk (the risk that the other party in an agreement will fail toperform its obligations) and management risk. They also involve the risk of mispricing or improper valuation andthe risk that changes in the value of the derivative instrument may not correlate exactly with the change in thevalue of the underlying asset, rate or index.

• Counterparty Risk. Counterparty risk is the risk that the other party or parties to an agreement or a participant to atransaction, such as a broker, might default on a contract or fail to perform by failing to pay amounts due orfailing to fulfill the obligations of the contract or transaction.

• Short Sales Risk. A short sale will result in a loss if the price of the security sold short increases between the dateof the short sale and the date on which the borrowed security must be returned. Short sales may give rise to aform of leverage. Leverage tends to exaggerate the effect of any increase or decrease in the value of portfoliosecurities. Short sales have the potential for unlimited loss.

• Securities of Other Investment Companies. Investments in other investment companies expose shareholders to theexpenses and risks associated with the investments of an Underlying Fund as well as to the expenses and risks ofthe underlying investment companies.

• Real Estate Securities. Just as real estate values go up and down, the value of the securities of companies involvedin the industry also fluctuates. Real estate securities, including real estate investment trusts (“REITs”), may beaffected by changes in the value of the underlying properties owned by the companies and by the quality oftenants’ credit.

• Depositary Receipts. Depositary receipts (including American Depositary Receipts and Global Depositary Receipts)are securities traded on a local stock exchange that represent securities issued by a foreign publicly-listed company.Depositary receipts are generally subject to the same risks of investing in the foreign securities they evidence orinto which they may be converted.

• Commodity Risk. Exposure to the commodities markets may subject an Underlying Fund to greater volatility thaninvestments in traditional securities, particularly if the investments involve leverage. The value ofcommodity-linked derivative instruments may be affected by changes in overall market movements, commodityindex volatility, changes in interest rates or factors affecting a particular industry or commodity and internationaleconomic, political and regulatory developments. The use of leveraged commodity-linked derivatives creates anopportunity for increased return, but also creates the possibility for a greater loss.

• Bank Obligations. The banking industry may be particularly susceptible to certain economic factors such as interestrate changes, adverse developments in the real estate market, fiscal and monetary policy and general economiccycles. The banking industry may also be impacted by legal and regulatory developments.

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• Infrastructure Companies. Infrastructure companies are subject to the risk that: the potential for realized revenuevolumes is significantly lower than projected and/or cost overruns; the nature of the concession fundamentallychanges during the life of the project (e.g., the state sponsor alters the terms); macroeconomic factors such as lowGDP growth or high nominal interest rates raise the average cost of funding; government regulation may affectrates charged to customers; government budgetary constraints impact projects; special tariffs are imposed; andchanges in tax laws, regulatory policies or accounting standards could be unfavorable. Other risks includeenvironmental damage due to a company’s operations or an accident, changes in market sentiment towardsinfrastructure and terrorist acts.

• Master Limited Partnerships (“MLPs”). Investing in MLPs involves certain risks related to investing in theunderlying assets of the MLPs and risks associated with pooled investment vehicles. MLPs that concentrate in aparticular industry or a particular geographic region are subject to risks associated with such industry or region.The benefit derived from an Underlying Fund’s investment in MLPs is largely dependent on the MLPs beingtreated as partnerships for federal income tax purposes.

• Illiquid Securities. An illiquid security may be difficult to sell quickly and at a fair price, which could cause anUnderlying Fund to realize a loss on the security if it was sold at a lower price than that at which it had beenvalued.

• Liquidity Risk. The market for certain investments may become illiquid under adverse or volatile market oreconomic conditions, making those investments difficult to sell. The market price of certain investments may falldramatically if there is no liquid trading market.

• Large Redemptions. Certain Underlying Funds are used as investments for certain funds of funds and in assetallocation programs and may have a large percentage of their Shares owned by such funds or held in suchprograms. Large redemption activity could result in an Underlying Fund incurring additional costs and beingforced to sell portfolio securities at a loss to meet redemptions.

• Global Financial Markets Risk. Global economies and financial markets are becoming increasingly interconnectedand conditions (including recent volatility and instability) and events (including natural disasters) in one country,region or financial market may adversely impact issuers in a different country, region or financial market. Inaddition, governmental and quasi-governmental organizations have taken a number of unprecedented actionsdesigned to support the markets. Such events and conditions may adversely affect the value of the Fund’s and/oran Underlying Fund’s securities, result in greater market or liquidity risk or cause difficulty valuing the Fund’sand/or an Underlying Fund’s portfolio instruments or achieving the Fund’s and/or an Underlying Fund’s objective.

The officers and Trustees of the Fund currently serve as officers and Trustees of the Underlying Funds. RIMcurrently serves as investment manager of the Fund and Underlying Funds. Therefore, conflicts may arise as thosepersons and RIM fulfill their fiduciary responsibilities to the Fund and to the Underlying Funds.

Please refer to the “Risks” section in the Fund’s Prospectus for further information.

Performance

The following bar chart illustrates the risks of investing in the Fund by showing the performance of the Fund sincethe beginning of the Fund’s operation. The highest and lowest returns for a full quarter during the periods shown in thebar chart are set forth next to the bar chart. The performance results shown in this section do not reflect any InsuranceCompany Separate Account or Policy charges. Those charges, if included, would have reduced the performance resultsshown in this section.

The table accompanying the bar chart further illustrates the risks of investing in the Fund by showing how theFund’s average annual total returns for the periods shown compare with index returns that measure broad marketperformance. The Fund is a fund of funds that invests in a variety of asset classes. Therefore, no single index provides anappropriate basis for comparison. For reference purposes, the indexes presented in the chart below have characteristicsthat represent the largest of these asset classes.

Past performance is no indication of future results.

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Calendar Year Total Returns

-60.00%

-40.00%

-20.00%

0.00%

20.00%

40.00%

60.00%

2008

2009

2010

2011

2012

2013

2014

2015

2016

(40.75)%

30.83%

15.09%

(6.22)%

15.68% 19.81%

3.48% (3.87)%10.85%

Highest Quarterly Return:20.33% (2Q/09)

Lowest Quarterly Return:(23.82)% (4Q/08)

Average annual total returnsfor the periods ended December 31, 2016 1 Year 5 Years

SinceInception*

Equity Growth Strategy Fund . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.85% 8.85% 2.71%Russell 1000® Index (reflects no deduction for fees, expenses or taxes) . . . . . . . . . . 12.05% 14.69% 6.74%Russell Developed ex-U.S. Large Cap Index (net of tax on dividends from foreignholdings) (reflects no deduction for fees or expenses). . . . . . . . . . . . . . . . . . . . . . . . . . 2.42% 6.36% 0.27%

* The Fund first issued Shares on May 1, 2007.

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to theRussell Indexes. Russell

®

is a trademark of Frank Russell Company.

Management

Investment Adviser

RIM is the investment adviser of the Fund and the Underlying Funds.

Portfolio Managers

Rob Balkema, a Senior Portfolio Manager, and Brian Meath, Chief Investment Officer of Multi-Asset Solutions, haveprimary responsibility for the management of the Fund. Mr. Balkema and Mr. Meath have managed the Fund sinceDecember 2014.

Additional Information

Purchase of Fund Shares

Each insurance company (“Insurance Company”) places orders for its accounts (“Separate Account”) which hold theinterests of each variable insurance product (“Policy”) owner based on, among other things, the amount of premiumpayments to be invested pursuant to such Policies. Individuals may not place orders directly with Russell InvestmentFunds (“RIF”) or the Funds. See the prospectus of the Separate Account and Policies of the Insurance Company for moreinformation on the purchase of Fund Shares and with respect to the availability for investment in specific Funds. TheFunds do not issue share certificates. Any minimum or subsequent investment requirements are governed by theapplicable Policy through which you invest.

For more information about how to purchase Shares, please see Additional Information About Purchase of FundShares in the Funds’ Prospectus.

Redemption of Fund Shares

Shares may be redeemed at any time by Insurance Companies on behalf of their Separate Accounts or their generalaccounts. Individuals may not place redemption orders directly with RIF or the Funds. Redemption requests for FundShares are based on premiums and transaction requests represented to the Funds by each Insurance Company as havingbeen received prior to the close of regular trading on the New York Stock Exchange (“NYSE”) (normally 4:00 p.m.Eastern Time) on any business day of the Funds (defined as a day on which the NYSE is open for regular trading).

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For more information about how to redeem Shares, please see Additional Information About Redemption of FundShares in the Funds’ Prospectus.

Taxes

Provided that the Funds and Separate Accounts of Insurance Companies investing in the Funds satisfy applicable taxrequirements, the Funds generally will not be subject to federal tax. Special tax rules apply to Insurance Companies,variable annuity contracts and variable life insurance contracts. For a discussion of the taxation of life insurancecompanies and the Separate Accounts, as well as the tax treatment of the Policies and the holders thereof, see thediscussion regarding “Federal Tax Considerations” included in the prospectus for the Policies.

For more information about Taxes, please see Additional Information About Taxes in the Funds’ Prospectus.

Servicing Arrangements

Some Insurance Companies have entered into arrangements with Russell Investments Fund Services, LLC (“RIFUS”)and/or Russell Investments Financial Services, LLC. (“RIFIS” or the “Distributor”) pursuant to which they may receivecompensation from RIFUS and/or the Distributor, from RIFUS’s and/or the Distributor’s own resources, for administrativeand/or other services provided by those Insurance Companies. These payments may create a conflict of interest byinfluencing the Insurance Company and your salesperson to recommend the Funds or a Fund over another investment orby influencing an Insurance Company’s decision to include the Funds as an underlying investment option in its Policy.Ask your salesperson or visit your Insurance Company’s web site for more information.

8 36-08-289 (0517)

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Credit Suisse Trust Commodity Return Strategy PortfolioBefore you invest, you may want to review the portfolio’s Prospectus, which contains more information about the portfolio and its risks. You canfind the portfolio’s Prospectus and other information about the portfolio online at www.credit-suisse.com/us/funds. You can also get thisinformation at no cost by calling 1 (877) 870-2874 or by sending an email request to [email protected]. The portfolio’s Prospectusand Statement of Additional Information, both dated May 1, 2017, as supplemented, along with the portfolio’s annual report to shareholders forthe fiscal year ended December 31, 2016, are incorporated by reference into this Summary Prospectus.

Investment ObjectiveThe portfolio seeks total return.

Fees and Portfolio ExpensesThe accompanying table describes the fees and expenses you may pay if you buy and hold shares of the portfolio. The fee table and the expenseexample do not reflect expenses incurred from investing through a variable contract or qualified plan and do not reflect variable annuity or lifeinsurance contract charges. If they did, the overall fees and expenses would be higher than those shown. Detailed information about the cost ofinvesting in the portfolio through a variable contract or qualified plan is presented in the contract prospectus through which the portfolio’s sharesare offered to you or in the plan documents or other informational materials supplied by plan sponsors.

1 The portfolio invests in Credit Suisse Cayman Commodity Fund II, Ltd., a wholly-owned subsidiary of the portfolio organized under the laws of the Cayman Islands (the “Subsidiary”). “Other Expenses” include expenses

of both the portfolio and the Subsidiary.2 Credit Suisse Trust (the “Trust”) and Credit Suisse Asset Management, LLC (“Credit Suisse”) have entered into a written contract limiting operating expenses to 1.05% of the portfolio’s average daily net assets at least

through May 1, 2018. This limit excludes certain expenses, including interest charges on fund borrowings, taxes, brokerage commissions, dealer spreads and other transaction charges, expenditures that are capitalized

in accordance with generally accepted accounting principles, acquired fund fees and expenses, short sale dividends, and extraordinary expenses (e.g., litigation and indemnification and any other costs and expenses

that may be approved by the Board of Trustees). The Trust is authorized to reimburse Credit Suisse for management fees previously limited and/or for expenses previously paid by Credit Suisse, provided, however, that

any reimbursements must be paid at a date not more than three years after the end of the fiscal year during which such fees were limited or expenses were paid by Credit Suisse and the reimbursements do not cause

the portfolio to exceed the expense limitation in the contract at the time the fees were limited or expenses were paid. This contract may not be terminated before May 1, 2018.

Example This example may help you compare the cost of investing in the portfolio with the cost of investing in other mutual funds. The example does notinclude expenses incurred from investing through a variable annuity or life insurance contract or qualified plan. If the example included theseexpenses, the figures shown would be higher.Assume you invest $10,000, the portfolio returns 5% annually, expense ratios remain the same and you close your account at the end of each ofthe time periods shown. Although your actual costs may be higher or lower, based on these assumptions, your cost would be:

Shareholder Fees (fees paid directly from your investment)

Maximum sales charge (load) imposed on purchases N/A

Maximum deferred sales charge (load) N/A

Maximum sales charge (load) on reinvested distributions N/A

Redemption fees N/A

Exchange fees N/A

Annual Portfolio Operating Expenses (expenses that you pay as a percentage of the value of your investment)

Management fee 0.59%

Distribution and service (12b-1) fee 0.25%

Other expenses1 0.23%

Total annual portfolio operating expenses 1.07%

Less: amount of fee limitations/expense reimbursements2 0.02%

Total annual portfolio operating expenses after fee limitations/expense reimbursements 1.05%

Summary ProspectusMay 1, 2017

Ticker: CCRSX

1 Year 3 Years 5 Years 10 Years

$107 $338 $588 $1,304

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Portfolio TurnoverThe computation of the portfolio’s portfolio turnover rate for regulatory purposes excludes trades of derivatives and instruments with a maturityof one year or less. However, the portfolio expects to engage in frequent trading of derivatives, which could have tax consequences that impactshareholders, such as the realization of taxable short-term capital gains. In addition, the portfolio could incur transaction costs, such ascommissions, when it buys and sells securities and other instruments. Transaction costs, which are not reflected in annual portfolio operatingexpenses or in the example, affect the portfolio’s performance. During the fiscal year ended December 31, 2016, the portfolio’s portfolio turnoverrate was 113% of the average value of its portfolio.

Principal Investment StrategiesThe portfolio is designed to achieve positive total return relative to the performance of the Bloomberg Commodity Index Total Return (the “BCOMIndex”). The portfolio intends to invest its assets in a combination of commodity-linked derivative instruments and fixed income securities. Theportfolio gains exposure to commodities markets by investing through the Subsidiary and in structured notes linked to the BCOM Index, othercommodity indices, or the value of a particular commodity or commodity futures contract or subset of commodities or commodity futurescontracts. The value of these investments will rise or fall in response to changes in the underlying index or commodity.The portfolio may invest up to 25% of its total assets in the Credit Suisse Cayman Commodity Fund II, Ltd., a wholly-owned subsidiary of theportfolio organized under the laws of the Cayman Islands (the “Subsidiary”). The portfolio will invest in the Subsidiary primarily to gain exposureto the commodities markets within the limitations of the federal tax laws, rules and regulations that apply to registered investment companies.Generally, the Subsidiary will invest in commodity-linked derivative instruments, but it will also invest in fixed income instruments, including U.S.government securities, U.S. government agency securities, corporate bonds, debentures and notes, mortgage-backed and other asset-backedsecurities, event-linked bonds, loan participations, bank certificates of deposit, fixed time deposits, bankers’ acceptances, commercial paper andother short-term fixed income securities. The primary purpose of the fixed income instruments held by the Subsidiary will be to serve as collateralfor the Subsidiary’s derivative positions; however, these instruments are also expected to earn income for the Subsidiary.The portfolio invests in a portfolio of fixed income securities normally having an average duration of one year or less, and emphasizes investment-grade fixed income securities.

Principal Risks of Investing in the PortfolioA Word About RiskAll investments involve some level of risk. Simply defined, risk is the possibility that you will lose money or not make money.Principal risk factors for the portfolio are discussed below. Before you invest, please make sure you understand the risks that apply to the portfolio.As with any mutual fund, you could lose money over any period of time.The portfolio is not a complete investment program and should only form a small part of a diversified portfolio. At any time, the risk of lossassociated with a particular instrument in the portfolio’s portfolio may be significantly higher than 50% of the value of the investment. Investorsin the portfolio should be willing to assume the greater risks of potentially significant short-term share price fluctuations.Investments in the portfolio are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any othergovernment agency.

Commodity Exposure RisksThe portfolio’s and the Subsidiary’s investments in commodity-linked derivative instruments may subject the portfolio to greater volatility thaninvestments in traditional securities, particularly if the instruments involve leverage. The value of commodity-linked derivative instruments maybe affected by changes in overall market movements, commodity index volatility, changes in interest rates, or factors affecting a particularindustry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatorydevelopments.Use of leveraged commodity-linked derivatives creates an opportunity for increased return but, at the same time, creates the possibility forgreater loss (including the likelihood of greater volatility of the portfolio’s net asset value), and there can be no assurance that the portfolio’s useof leverage will be successful.

Correlation RiskChanges in the value of a hedging instrument may not match those of the investment being hedged. In addition, certain of the portfolio’scommodity-linked derivative investments may result in the portfolio’s performance diverging from the BCOM Index, perhaps materially. Forexample, a structured note can be structured to limit the loss or the gain on the investment, which would result in the portfolio not participatingin declines or increases in the BCOM Index that exceed the limits.

Credit RiskThe issuer of a debt instrument or the counterparty to a contract, including derivatives contracts, may default or otherwise become unable tohonor a financial obligation. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness also may affect the valueof the portfolio’s investment in that issuer.

Derivatives RiskDerivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index. Theportfolio typically uses derivatives as a substitute for taking a position in the underlying asset and/or as part of a strategy designed to reduceexposure to other risks, such as interest rate or currency risk. The portfolio also may use derivatives for leverage. The portfolio’s use of derivativeinstruments, particularly commodity-linked derivatives, involves risks different from, or possibly greater than, the risks associated with investingdirectly in securities and other traditional investments. Derivatives are subject to a number of risks described elsewhere in the Prospectus, such ascommodity exposure risks, correlation risk, liquidity risk, interest rate risk, market risk and credit risk. Also, suitable derivative transactions may notbe available in all circumstances and there can be no assurance that the portfolio will engage in these transactions to reduce exposure to other

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risks when that would be beneficial. In December 2015, the SEC proposed a new rule to regulate the use of derivatives by registered investmentcompanies, such as the portfolio. If the new rule goes into effect, it could limit the ability of the portfolio to invest or remain invested in derivatives.

Exposure RiskThe risk associated with investments (such as derivatives) or practices (such as short selling) that increase the amount of money the portfoliocould gain or lose on an investment.• Hedged Exposure risk could multiply losses generated by a derivative or practice used for hedging purposes. Such losses should be

substantially offset by gains on the hedged investment. However, while hedging can reduce or eliminate losses, it can also reduce or eliminategains.

• Speculative To the extent that a derivative or practice is not used as a hedge, the portfolio is directly exposed to its risks. Gains or losses fromspeculative positions in a derivative may be much greater than the derivative’s original cost. For example, potential losses from commodity-linked notes or swap agreements, from writing uncovered call options and from speculative short sales are unlimited.

Fixed Income RiskThe market value of fixed income investments will change in response to interest rate changes and other factors, such as changes in the effectivematurities and credit ratings of fixed income investments. During periods of falling interest rates, the values of outstanding fixed income securitiesand related financial instruments generally rise. Conversely, during periods of rising interest rates, the values of such securities and relatedfinancial instruments generally decline. Fixed income investments are also subject to credit risk.

Focus RiskThe portfolio will be exposed to the performance of commodities in the BCOM Index, which may from time to time have a small number ofcommodity sectors (e.g., energy, metals or agricultural) representing a large portion of the index. As a result, the portfolio may be subject togreater volatility than if the index were more broadly diversified among commodity sectors. If the portfolio is exposed to a significant extent to aparticular commodity or subset of commodities, the portfolio will be more exposed to the specific risks relating to such commodity orcommodities and will be subject to greater volatility than if it were more broadly diversified among commodity sectors.

Futures Contracts RiskThe risks associated with the portfolio’s use of futures contracts and swaps and structured notes that reference the price of futures contractsinclude the risk that: (i) changes in the price of a futures contract may not always track the changes in market value of the underlying referenceasset; (ii) trading restrictions or limitations may be imposed by an exchange, and government regulations may restrict trading in futures contracts;and (iii)  if the portfolio has insufficient cash to meet margin requirements, the portfolio may need to sell other investments, including atdisadvantageous times.

Interest Rate RiskChanges in interest rates may cause a decline in the market value of an investment. With bonds and other fixed income instruments, a rise ininterest rates typically causes a fall in values, while a fall in interest rates typically causes a rise in values. The portfolio may be subject to a greaterrisk of rising interest rates due to the current period of historically low rates and the effect of potential government fiscal policy initiatives andresulting market reaction to those initiatives. Generally, the longer the maturity or duration of a debt instrument, the greater the impact of achange in interest on the instrument’s value. In periods of market volatility, the market values of fixed income securities may be more sensitive tochanges in interest rates.

Leveraging RiskThe portfolio may invest in certain derivatives that provide leveraged exposure. The portfolio’s investment in these instruments generally requiresa small investment relative to the amount of investment exposure assumed. As a result, such investments may cause the portfolio to lose morethan the amount it invested in those instruments. The net asset value of the portfolio when employing leverage will be more volatile and sensitiveto market movements. Leverage may involve the creation of a liability that requires the portfolio to pay interest.

Liquidity RiskCertain portfolio holdings, such as commodity-linked notes and swaps, may be difficult or impossible to sell at the time and the price that theportfolio would like. The portfolio may have to lower the price, sell other holdings instead or forgo an investment opportunity. Any of these couldhave a negative effect on portfolio management or performance.

Market RiskThe market value of a security may fluctuate, sometimes rapidly and unpredictably. These fluctuations, which are often referred to as “volatility,”may cause an instrument to be worth less than it was worth at an earlier time. Market risk may affect a single issuer, industry, commodity, sectorof the economy, or the market as a whole. Market risk is common to most investments – including stocks, bonds and commodities, and the mutualfunds that invest in them.Bonds and other fixed income securities generally involve less market risk than stocks and commodities. The risk of bonds can vary significantlydepending upon factors such as issuer and maturity. The bonds of some companies may be riskier than the stocks of others.

Non-Diversified StatusThe portfolio is considered a non-diversified investment company under the Investment Company Act of 1940, as amended (the “1940 Act”), andis permitted to invest a greater proportion of its assets in the securities of a smaller number of issuers. As a result, the portfolio may be subject togreater volatility with respect to its portfolio securities than a fund that is diversified.

Portfolio Turnover RiskThe portfolio expects to engage in frequent trading of derivatives. Active and frequent trading may lead to the realization and distribution toshareholders of higher short-term capital gains, which would increase their tax liability. Frequent trading also increases transaction costs, whichcould detract from the portfolio’s performance.

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Structured Note RiskThe value of a structured note will be influenced by time to maturity, level of supply and demand for the type of note, interest rate and marketvolatility, changes in the issuer’s credit rating, and economic, legal, political, or geographic events that affect the reference asset. In addition, theremay be a lag between a change in the value of the underlying reference asset and the value of the structured note.

Subsidiary RiskBy investing in the Subsidiary, the portfolio is indirectly exposed to the risks associated with the Subsidiary’s investments. The derivatives andother investments held by the Subsidiary are generally similar to those that are permitted to be held by the portfolio and are subject to the samerisks that apply to similar investments if held directly by the portfolio. These risks are described elsewhere in the Prospectus.The Subsidiary is not registered under the 1940 Act and, unless otherwise noted in the Prospectus, is not subject to all the investor protections ofthe 1940 Act. However, the portfolio wholly owns and controls the Subsidiary, and the portfolio and the Subsidiary are both managed by CreditSuisse, making it unlikely that the Subsidiary will take action contrary to the interests of the portfolio and its shareholders. The portfolio’s Boardof Trustees has oversight responsibility for the investment activities of the portfolio, including its investment in the Subsidiary, and the portfolio’srole as sole shareholder of the Subsidiary. The Subsidiary will be subject to the same investment restrictions and limitations, and follow the samecompliance policies and procedures, as the portfolio.Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the portfolio and/or the Subsidiary to continueto operate as it does currently and could adversely affect the portfolio.

Swap Agreements RiskSwap agreements involve the risk that the party with whom the portfolio has entered into the swap will default on its obligation to pay theportfolio and the risk that the portfolio will not be able to meet its obligations to pay the other party to the agreement.

Tax RiskIn order to qualify as a Regulated Investment Company (a “RIC”) under the Internal Revenue Code of 1986, as amended (the “Code”), the portfoliomust meet certain requirements regarding the source of its income, the diversification of its assets and the distribution of its income. The InternalRevenue Service (“IRS”) has issued a ruling that income realized directly from certain types of commodity-linked derivatives would not bequalifying income. As a result, the portfolio’s ability to realize income from direct investments in such commodity-linked derivatives as part of itsinvestment strategy would be limited to a maximum of 10% of its gross income. To comply with the ruling, the portfolio seeks to gain exposureto the commodity markets primarily through investments in the Subsidiary, which invests in commodity-linked swaps, commodity futures andother derivatives, and directly through investments in commodity index-linked notes. If the portfolio fails to qualify as a RIC, the portfolio will besubject to federal income tax on its net income at regular corporate rates (without reduction for distributions to shareholders). When distributed,that income also would be taxable to shareholders as an ordinary dividend to the extent attributable to the portfolio’s earnings and profits. If theportfolio were to fail to qualify as a RIC and became subject to federal income tax, shareholders of the portfolio would be subject to diminishedreturns. The portfolio anticipates treating income and gain from the Subsidiary and from commodity-linked notes as qualifying income.

U.S. Government Securities RiskObligations of U.S. government agencies and authorities are supported by varying degrees of credit but generally are not backed by the full faithand credit of the U.S. government. No assurance can be given that the U.S. government will provide financial support to its agencies andauthorities if it is not obligated by law to do so.

PerformanceThe accompanying bar chart and table provide an indication of the risks of investing in the portfolio. The bar chart shows you how portfolioperformance has varied from year to year for up to 10 years (if applicable). The table compares the portfolio’s performance over time to that of abroad-based securities market index. The table also compares the portfolio’s performance to the BCOM Index, which is currently composed offutures contracts on 22 physical commodities. The bar chart and table do not reflect additional charges and expenses which are, or may be,imposed under the variable contracts or plans; such charges and expenses are described in the prospectus of the insurance company separateaccount or in the plan documents or other informational materials supplied by plan sponsors. Inclusion of these charges would reduce the totalreturn for the periods shown. As with all mutual funds, past performance is not a prediction of future performance.The portfolio makes updated performance available at the portfolio’s website (www.credit-suisse.com/us/funds) or by calling Credit Suisse Fundsat 877-870-2874.

Best quarter: 16.74% (Q2 08)Worst quarter: -28.82% (Q4 08)Inception date: 2/28/06

16.66%

-12.65%-33.72%

-10.27% -17.01%

12.02%

-25.10%-2.09%

17.33%

20082007 201120102009 2012 2013 2014 2015 2016

19.48%

Year-by-Year Total Returns

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ManagementInvestment manager: Credit Suisse Asset Management, LLC (“Credit Suisse”)Portfolio managers: The Credit Suisse Commodities Management Team is responsible for the day-to-day management of the portfolio. NelsonLouie and Christopher Burton, each a Managing Director of Credit Suisse, are the co-lead portfolio managers of the team and have been teammembers since August 2010 and the portfolio’s inception in February 2006, respectively.

Purchase and Sale of Portfolio SharesShares of the portfolio may be purchased or redeemed only through variable annuity contracts and variable life insurance policies offered by theseparate accounts of certain insurance companies or through tax-qualified pension and retirement plans. Shares of the portfolio may bepurchased and redeemed each day the New York Stock Exchange is open, at the portfolio’s net asset value determined after receipt of a requestin good order.The portfolio does not have any initial or subsequent investment minimums. However, your life insurance company, pension plan or retirementplan may impose investment minimums.

Tax InformationDistributions made by the portfolio to an insurance company separate account, and exchanges and redemptions of portfolio shares made by aseparate account, ordinarily do not cause the corresponding contract holder to recognize income or gain for federal income tax purposes. See theaccompanying contract prospectus for information regarding the federal income tax treatment of the distributions to separate accounts and theholders of the contracts.

Payments to Broker­Dealers and Other Financial RepresentativesThe portfolio and its related companies may pay broker-dealers or other financial intermediaries (such as a bank or insurance company) for thesale of portfolio shares and related services. These payments may create a conflict of interest by influencing your broker-dealer or otherrepresentative or its employees or associated persons to recommend the portfolio over another investment. Ask your financial representative orvisit your financial representative’s website for more information.

Average Annual Total Returns

One Year Five Years Ten YearsPeriod Ended 12/31/16: 2016 2012-2016 2007-2016

Commodity Return Strategy Portfolio 12.02% -9.36% -5.31%

Bloomberg Commodity Index Total Return(Reflects no deductions for fees or expenses) 11.77% -8.95% -5.58%

Standard & Poor’s 500 Index (Reflects no deductions for fees or expenses) 11.96% 14.66% 6.95%

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Business Continuity PlanNorthwestern Mutual Investment Services, LLC (“NMIS”) has a business continuity plan to provide for an orderly return to normal business operations after a significant disruption. Where necessary, NMIS has integrated its plan with the business continuity plan of its parent, The Northwestern Mutual Life Insurance Company, and plans of key third-party services providers.

While a catastrophic event may negatively impact our ability to continue to transact business, we have attempted to identify potential disruptions and methods to continue to operate in the event such disruptions occur. The strategy of NMIS’s business continuity plan is to take all reasonable and appropriate steps to protect our people, our infrastructure, the services provided to our customers, and the services provided to our field.

NMIS’s business continuity plan addresses: data back up and recovery; mission critical systems; financial and operational assessments; alternative communications with customers, employees, and regulators; alternate physical location of employees; critical supplier, contractor, bank and counter-party impact; regulatory reporting; and assuring our customers prompt access to their funds and securities if we were unable to continue our business.

The information below is intended as a synopsis of our business continuity plan. Since the timing and extent of significant business disruptions are by nature unpredictable, we have reserved flexibility in our plan to allow us to respond to tangible events in the manner we deem appropriate as they occur.

Contacting UsYour primary contact in the event of a significant business disruption affecting the home office is your financial representative. If your financial representative or the network office to which your financial representative is associated with experiences a significant business disruption, you can contact the home office at 1-866-664-7737. If a significant business disruption affects your ability to contact our home office please go to www.northwesternmutual.com for instructions on how to obtain information regarding your accounts.

Strategy by Disruption TypeThe strategy of NMIS’s business continuity plan is to address three scenarios in which a Northwestern Mutual campus is impacted by a local business disruption. The scenarios are (1) part or all of the Milwaukee, Wisconsin Campus disabled, (2) part or all of the Franklin, Wisconsin Campus disabled, and (3) significant portion of staff unable to work (for example, pandemic). In all scenarios, NMIS plans to continue business, transfer operations to our clearing firm, if necessary, and notify our clients through our web site or via the home office phone number which are both listed in the paragraph above. If the significant business disruption is so severe that it prevents NMIS from processing transactions, NMIS will take all necessary steps to assure our clients’ prompt access to their funds and securities.

Milwaukee Campus Only DisruptionIf NMIS loses the ability to perform business at part or all of the Milwaukee campus, the staff associated with the mission critical functions will be relocated to an established off-site location outside of the affected area. The firm expects to recover and resume business as soon as reasonably practical depending on the severity of the disruption.

Franklin Campus Only DisruptionIf NMIS loses the ability to perform business at part or all of the Franklin campus, the staff associated with the mission critical functions will be relocated to an established off-site location outside of the affected area. The firm expects to recover and resume business as soon as reasonably practical depending on the severity of the disruption.

Staff Only DisruptionIf a staff only disruption (for example, pandemic) was to occur at either the Milwaukee or Franklin campus, the firm will redirect the available staff, to service the critical and essential processes needed to keep the firm running with little impact. If necessary, certain key employees will work from an established remote location to assist in the recovery of business operations.

Changes and ModificationsThe firm may, from time to time, alter or revise the plan as necessary to support current business needs. Certain aspects of the plan are tested on a regular basis and updated as necessary. For a current copy of this notice, go to www.northwesternmutual.com and search business continuity or contact your Northwestern Mutual representative. If you have questions about our business continuity plan, please contact us at 1-866-664-7737.

SIPC DisclosureVariable insurance products are offered through Northwestern Mutual Investment Services, LLC (“NMIS”), a wholly owned subsidiary of The Northwestern Mutual Life Insurance Company. NMIS is a broker-dealer and investment adviser registered with the SEC and is a member of FINRA and SIPC. You may obtain information about SIPC, including the SIPC brochure, by contacting SIPC at 202-371-8300 or visiting its web site at www.sipc.org.

ComplaintsComplaints concerning Northwestern Mutual’s variable life insurance or variable annuity contracts may be directed to:

Variable Life Variable AnnuityNorthwestern Mutual Northwestern MutualPolicyowner Services Dept. Investment Client Services Dept.Variable Life Service Center P.O. Box 3223P.O. Box 3220 Milwaukee, WI 53202-3223Milwaukee, WI 53201-3220 888-455-2232866-424-2609

17-1418 (1107) (REV 0512) This page is not part of the Prospectus.

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PAIDNORTHWESTERN

MUTUALPO BOX 3095

MILWAUKEE WI 53201-3095

VARIABLE LIFE

Northwestern Mutual is the marketing name for The Northwestern Mutual Life Insurance Company (NM), Milwaukee, WI (life and disability insurance, annuities, and life insurance with long-term care benefits) and its subsidiaries. Northwestern Long Term Care Insurance Company, Milwaukee, WI (long-term care insurance) is a subsidiary of NM.www.northwesternmutual.com

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