# EDGAR Filing Document

**Accession Number:** 0000742212
**File Stem:** 0001193125-25-195465
**Filing Date:** 2025-9
**Character Count:** 2774
**Document Hash:** ded31b8b8770f44af79446e6ea262ba9
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-195465.hdr.sgml**: 20250904

**ACCESSION NUMBER**: 0001193125-25-195465

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250904

**DATE AS OF CHANGE**: 20250904

**EFFECTIVENESS DATE**: 20250904

**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:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 002-89971
- **FILM NUMBER:** 251292023

**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

### High Yield Bond Portfolio (Series ID: S000000046)

---

|  |  |
|:---|:---|
| Class Name                | Class ID   |
| High Yield Bond Portfolio | C000000081 |

---

## Series and Classes Contracts Data

### High Yield Bond Portfolio (Series ID: S000000046)

| Class ID   | Class Name                | Ticker Symbol   |
|:---|:---|:---|
| C000000081 | High Yield Bond Portfolio |  |

**Northwestern Mutual Series Fund, Inc.** <br>Supplement Dated September 4, 2025, to the <br>Statement of Additional Information Dated May 1, 2025, as Supplemented

This Supplement revises certain information contained in the Statement of Additional Information (the "SAI") for the Northwestern Mutual Series Fund, Inc. (the "Fund") dated May 1, 2025, as supplemented. You should read this Supplement together with the SAI.

***<u>Sub-Advisory Fee Update – High Yield Bond Portfolio</u>***

Effective November 1, 2025, the SAI is revised by replacing the fifth sentence of the paragraph relating to the sub-advisory fees for Federated Investment Management Company ("Federated") relating to the High Yield Bond Portfolio that appears on page B-68 under the sub-section of the SAI section titled "**The Sub-Advisers**," under "INVESTMENT ADVISORY AND OTHER SERVICES" with the following:

"For services provided for the High Yield Bond Portfolio, Mason Street Advisors pays Federated a fee at the annual rate of 0.35% of the Portfolio's net assets on the first $100 million of assets, 0.25% on the next $150 million, 0.15% on the next $750 million, 0.125% on the next $500 million, and 0.10% on assets in excess of $1.5 billion."

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

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