STRATEGIC BOND FUND

Fund Overview

Adviser:

Russell Investment Management, LLC

Fund Manager(s):

Colchester Global Investors Limited; Insight Investment International Limited (formerly, Pareto Investment Management Limited); Logan Circle Partners, L.P.; Schroder Investment Management North America Inc.; Scout Investments, Inc.; Western Asset Management Company and Western Asset Management Company Limited. (Money managers listed are current as of 09/30/18. Russell has the right to employ or terminate a money manager at any time and without prior notification, as is consistent with its role as investment manager.)

Objective/Focus:

A multi-manager fund that invests primarily in bonds. Bonds are fixed-income securities representing debt obligations that require the issuer to repay the bondholders the principal amount borrowed and to generally pay interest. The objective is to provide current income and the preservation of capital.

Asset Class:

Bond

Style:

Broad Market/Sector Rotation

Bonds and other debt obligations are affected by changes in interest rates, inflation risk and the creditworthiness of their issuers. High yield bonds generally have greater price swings and higher default risks than investment grade bonds. Return of principal is not guaranteed. In contrast to owning individual bonds, there are ongoing fees and expenses associated with owning shares of bond funds.

Overseas investments can pose more risks than domestic investments due to fluctuations in foreign stock markets, currency values, interest rates, government regulations and political conditions.

Fund Facts as of 09/30/18

Fund Inception

04-30-1999

First Available for Variable Annuity

04-30-1999

First Available for Variable Life

06-30-1999

Net Assets

$883.02 Million

Top 10 Portfolio Holdings % of Net Assets

United States Treasury Notes

3.1%

United States Treasury Notes

2.7%

United States Treasury Notes

2.5%

United States Treasury Notes

1.9%

United States Treasury Notes

1.9%

United States Treasury Notes

1.7%

United States Treasury Notes

1.5%

United States Treasury Inflation Indexed Bonds

1.3%

United States Treasury Notes

1.2%

United States Treasury Inflation Indexed Bonds

1.2%

% of Total Portfolio

19.0%

Before investing in a variable product, you should carefully consider the objectives, risks and charges associated with its investment options. For this and other information about a Contract, you should obtain the appropriate Contract and underlying fund prospectuses by contacting your Northwestern Mutual Financial Representative. Read the prospectuses carefully before you invest.

Mason Street Advisors, LLC (MSA) is the principal investment adviser for all the Portfolios in the Northwestern Mutual Series Fund (Series Fund). (Portfolios in the Series Fund are identified by the parenthetical next to the portfolio name.) MSA has engaged and oversees sub-advisers who provide day-to-day management for certain of the Series Fund Portfolios. Each sub-adviser may be replaced without the approval of shareholders. Please see the prospectus for more information. Additional fund options are advised by Russell Investments, Fidelity Investments, Neuberger Berman Investment Advisers LLC and Credit Suisse Asset Management, LLC

All securities are offered through Northwestern Mutual Investment Services LLC, (NMIS), 720 E. Wisconsin Avenue, Milwaukee, WI 53202, 1-866-664-7737. Member FINRA and SIPC. NMIS is a subsidiary of Northwestern Mutual.