# EDGAR Filing Document

**Accession Number:** 0000067160
**File Stem:** 0001133228-25-006045
**Filing Date:** 2025-6
**Character Count:** 8188
**Document Hash:** 9c19b119d50ebcd2657b7b2903fd5ad3
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001133228-25-006045.hdr.sgml**: 20250604

**ACCESSION NUMBER**: 0001133228-25-006045

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250604

**DATE AS OF CHANGE**: 20250604

**EFFECTIVENESS DATE**: 20250604

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MML SERIES INVESTMENT FUND
- **CENTRAL INDEX KEY:** 0000067160

**ORGANIZATION NAME:**
- **EIN:** 042476032
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 002-39334
- **FILM NUMBER:** 251023162

**BUSINESS ADDRESS:**
- **STREET 1:** 1295 STATE STREET
- **CITY:** SPRINGFIELD
- **STATE:** MA
- **ZIP:** 01111
- **BUSINESS PHONE:** 413-744-1000

**MAIL ADDRESS:**
- **STREET 1:** 1295 STATE STREET
- **CITY:** SPRINGFIELD
- **STATE:** MA
- **ZIP:** 01111

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MML EQUITY INVESTMENT CO INC
- **DATE OF NAME CHANGE:** 19850227

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MML INVESTMENT CO INC
- **DATE OF NAME CHANGE:** 19811109

## Series and Classes Contracts Data

### MML Equity Index Fund (Series ID: S000003823)

---

|  |  |
|:---|:---|
| Class Name      | Class ID   |
| Class I         | C000010665 |
| Class II        | C000010672 |
| Class III       | C000010673 |
| Service Class I | C000067760 |

---

### MML Mid Cap Value Fund (Series ID: S000011488)

---

|  |  |
|:---|:---|
| Class Name    | Class ID   |
| Initial Class | C000031718 |
| Service Class | C000067776 |

---

## Series and Classes Contracts Data

### MML Equity Index Fund (Series ID: S000003823)

| Class ID   | Class Name      | Ticker Symbol   |
|:---|:---|:---|
| C000010665 | Class I         |  |
| C000010672 | Class II        |  |
| C000010673 | Class III       |  |
| C000067760 | Service Class I |  |

### MML Mid Cap Value Fund (Series ID: S000011488)

| Class ID   | Class Name    | Ticker Symbol   |
|:---|:---|:---|
| C000031718 | Initial Class |  |
| C000067776 | Service Class |  |

#### MML SERIES INVESTMENT FUND <br>

#### MML Equity Index Fund<br>

#### (the "Fund")<br>

#### Supplement dated June 4, 2025 to the<br>

#### Prospectus dated April 25, 2025 and the<br>

#### Summary Prospectus dated April 25, 2025
This supplement provides new and additional information beyond that contained in the Prospectus and Summary Prospectus. It should be retained and read in conjunction with the Prospectus and Summary Prospectus.

*Effective immediately, the following information replaces the information for **Paul Whitehead** found under the heading **Portfolio Manager(s)** in the section titled **Management** (page 15 of the Prospectus):* 

#### Peter Sietsema, CFA is a Director at BlackRock. He has managed the Fund since May 2025.
*Effective immediately, the following information replaces the information for **Paul Whitehead** found under **BlackRock Investment Management, LLC** under the heading **Subadvisers and Portfolio Managers** in the section titled **Management of the Funds** on pages 120 and 121 of the Prospectus:* 

**Peter Sietsema, CFA____________________________________________________________________________________ is jointly and primarily responsible for the day-to-day management of the *MML Equity Index Fund's* portfolio, including setting the Fund's overall investment strategy and overseeing the management of the Fund. Mr. Sietsema is a Director of BlackRock, Inc. and the U.S. Head of North American Portfolio Management for Index Equity Investments within BlackRock Global Markets & Index Investments. Mr. Sietsema's service with the firm dates back to 2007, including his years with Barclays Global Investors ("BGI"), which merged with BlackRock in 2009. At BGI, he was a portfolio manager within the U.S. Index Portfolio Management group in San Francsico. Mr. Sietsema began his career as Senior Manager of Alternative Investments at State Street.** 

#### PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE

#### MMLPRO-25-01<br>

#### EI-25-01

**MML SERIES INVESTMENT FUND** 

<br> #### MML Mid Cap Value Fund<br>

#### (the "Fund")<br>

#### Supplement dated June 4, 2025 to the<br>

#### Prospectus dated April 25, 2025 and the<br>

#### Summary Prospectus dated April 25, 2025
This supplement provides new and additional information beyond that contained in the Prospectus and Summary Prospectus, and any previous supplements. It should be retained and read in conjunction with the Prospectus and Summary Prospectus, and any previous supplements.

*Effective immediately, the following information replaces similar information for **Michael Liss** of **American Century Investment Management, Inc.** found under the heading **Portfolio Manager(s)** in the section titled **Management** (page 64 of the Prospectus):* 

**Michael Liss, CFA is a Vice President and Senior Portfolio Manager at American Century. He has managed the Fund since its inception (May 2006). He is expected to step down as a portfolio manager of the Fund on December 31, 2025.** 

*Effective immediately, the following information replaces similar information for **Michael Liss** found under **American Century Investment Management, Inc.** under the heading **Subadvisers and Portfolio Managers** in the section titled **Management of the Funds** on page 119 of the Prospectus:* 

#### Michael Liss, CFA ______________________________________________________________________________________ <br>
**is a portfolio manager of the *MML Mid Cap Value Fund,* which is managed on a team basis. He is jointly and primarily responsible for the day-to-day management of the Fund. Mr. Liss is a Vice President and Senior Portfolio Manager for American Century. Mr. Liss joined American Century in 1998 and became a portfolio manager in 2004. He is expected to step down as a portfolio manager of the Fund on December 31, 2025.** 

#### PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE

#### MMLPRO-25-02<br>

#### MMLMCV-25-01

**MML SERIES INVESTMENT FUND** 

<br> #### MML Equity Index Fund<br>

#### MML Mid Cap Value Fund <br>

#### Supplement dated June 4, 2025 to the<br>

#### Statement of Additional Information dated April 25, 2025
This supplement provides new and additional information beyond that contained in the Statement of Additional Information ("SAI"). It should be retained and read in conjunction with the SAI.

*Effective immediately, the following information replaces the information for the **MML Equity Index Fund** for **Paul Whitehead** found under **BlackRock Investment Management, LLC** on page B-240 in the section titled **Appendix C — Additional Portfolio Manager Information:***

The portfolio managers of MML Equity Index are Jennifer Hsui and Peter Sietsema.

#### Other Accounts Managed:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Number of**<br>**Accounts**<br>**Managed\*** | **Total**<br>**Assets\*** | **Number of Accounts**<br>**Managed for**<br>**which Advisory Fee is**<br>**Performance-Based\*** | **Total**<br>**Assets\***  |
| **Peter Sietsema** | **Peter Sietsema** | **Peter Sietsema** | **Peter Sietsema** | **Peter Sietsema** |
| Registered investment companies\*\* | 350 | $2.68 trillion | 0 | $0 |
| Other pooled investment vehicles | &nbsp;&nbsp;&nbsp;3 | $88.77 million | 0 | $0 |
| Other accounts | &nbsp;&nbsp;&nbsp;2 | $4.14 billion | 0 | $0 |

---

\*<br> The information provided is as of January 31, 2025.

\*\*<br> Does not include MML Equity Index.

#### Ownership of Securities:
As of January 31, 2025, Mr. Sietsema did not own any shares of MML Equity Index.

*Effective immediately, the following information replaces similar information for the **MML Mid Cap Value Fund** found under **American Century Investment Management, Inc.** on page B-234 in the section titled **Appendix C — Additional Portfolio Manager Information:***

The portfolio managers of MML Mid Cap Value are Michael Liss, Nathan Rawlins, Kevin Toney, and Brian Woglom. Mr. Liss is expected to step down as a portfolio manager of the Fund on December 31, 2025.

#### PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE

#### MMLSAI-25-01