# EDGAR Filing Document

**Accession Number:** 0000742212
**File Stem:** 0001193125-25-154074
**Filing Date:** 2025-7
**Character Count:** 2871
**Document Hash:** 187d121ec9e46d5930c341f45b1d7a1a
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-154074.hdr.sgml**: 20250701

**ACCESSION NUMBER**: 0001193125-25-154074

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250701

**DATE AS OF CHANGE**: 20250701

**EFFECTIVENESS DATE**: 20250701

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** NORTHWESTERN MUTUAL SERIES FUND INC
- **CENTRAL INDEX KEY:** 0000742212

**ORGANIZATION NAME:**
- **EIN:** 391603401
- **STATE OF INCORPORATION:** MD
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 002-89971
- **FILM NUMBER:** 251097077

**BUSINESS ADDRESS:**
- **STREET 1:** 720 E WISCONSIN AVE
- **CITY:** MILWAUKEE
- **STATE:** WI
- **ZIP:** 53202
- **BUSINESS PHONE:** 4142992508

**MAIL ADDRESS:**
- **STREET 1:** 720 EAST WISCONSIN AVE
- **CITY:** MILWAUKEE
- **STATE:** WI
- **ZIP:** 53202

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** NORTHWESTERN MUTUAL VARIABLE LIFE SERIES FUND INC
- **DATE OF NAME CHANGE:** 19940830

## Series and Classes Contracts Data

### Index 500 Stock Portfolio (Series ID: S000000043)

| Class ID   | Class Name                | Ticker Symbol   |
|:---|:---|:---|
| C000000078 | Index 500 Stock Portfolio |  |

**Northwestern Mutual Series Fund, Inc.** <br>**Index 500 Stock Portfolio**

Supplement Dated July 1, 2025 to the <br>Summary Prospectus for the Index 500 Stock Portfolio Dated May 1, 2025

The following information supplements the Summary Prospectus for the Index 500 Stock Portfolio of Northwestern Mutual Series Fund, Inc. (the "Fund") dated May 1, 2025 (the "Summary Prospectus"). You should read this Supplement together with the Summary Prospectus.

***<u>Portfolio Managers Update – Index 500 Stock Portfolio</u>***

Effective June 30, 2025, Matt Waldron and Steven White replaced Paul Whitehead as co-portfolio managers for the Index 500 Stock Portfolio. Accordingly, the "Portfolio Managers" information set forth under the "Summary – PORTFOLIO MANAGEMENT" section is hereby deleted and replaced with the following:

"**Portfolio Managers**: *Peter Sietsema*, CFA, Director, joined BlackRock in 2007 and has managed the Portfolio May 2022.

*Jennifer Hsui*, CFA, Managing Director and Co-head and Chief Investment Officer of Global Index Equity joined BlackRock in 2006 and has managed the Portfolio since February 2021.

*Matt Waldron*, CFA, Managing Director and U.S. Head of International Portfolio Management, joined BlackRock in 2003 and has managed the Portfolio since 2025.

*Steven White*, Director and Head of the Active Risk Index ETF team in the Americas, and co-CIO for Index Equity Investments within BlackRock Global Markets & Index Investments, joined BlackRock in 2011 and has managed the Portfolio since 2025."

**Please retain this Supplement for future reference.**

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