# EDGAR Filing Document

**Accession Number:** 0002018846
**File Stem:** 0000912938-25-000263
**Filing Date:** 2025-12
**Character Count:** 29502
**Document Hash:** c959d31e19884695b83bcd2bfed37f33
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000912938-25-000263.hdr.sgml**: 20251210

**ACCESSION NUMBER**: 0000912938-25-000263

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20251210

**DATE AS OF CHANGE**: 20251210

**EFFECTIVENESS DATE**: 20251210

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MFS Active Exchange Traded Funds Trust
- **CENTRAL INDEX KEY:** 0002018846

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0228

**FILING VALUES:**
- **FORM TYPE:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-278691
- **FILM NUMBER:** 251561961

**BUSINESS ADDRESS:**
- **STREET 1:** 111 HUNTINGTON AVENUE
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199
- **BUSINESS PHONE:** 617-954-5000

**MAIL ADDRESS:**
- **STREET 1:** 111 HUNTINGTON AVENUE
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199

## Series and Classes Contracts Data

### MFS Active Core Plus Bond ETF (Series ID: S000085666)

---

|  |  |  |
|:---|:---|:---|
| Class Name                    | Ticker Symbol | Class ID   |
| MFS Active Core Plus Bond ETF | MFSB          | C000251000 |

---

### MFS Active Growth ETF (Series ID: S000085667)

---

|  |  |  |
|:---|:---|:---|
| Class Name            | Ticker Symbol | Class ID   |
| MFS Active Growth ETF | MFSG          | C000251001 |

---

### MFS Active Intermediate Muni Bond ETF (Series ID: S000085668)

---

|  |  |  |
|:---|:---|:---|
| Class Name                            | Ticker Symbol | Class ID   |
| MFS Active Intermediate Muni Bond ETF | MFSM          | C000251002 |

---

### MFS Active International ETF (Series ID: S000085669)

---

|  |  |  |
|:---|:---|:---|
| Class Name                   | Ticker Symbol | Class ID   |
| MFS Active International ETF | MFSI          | C000251003 |

---

### MFS Active Value ETF (Series ID: S000085670)

---

|  |  |  |
|:---|:---|:---|
| Class Name           | Ticker Symbol | Class ID   |
| MFS Active Value ETF | MFSV          | C000251004 |

---

### MFS Active Mid Cap ETF (Series ID: S000094824)

---

|  |  |  |
|:---|:---|:---|
| Class Name             | Ticker Symbol | Class ID   |
| MFS Active Mid Cap ETF | MMID          | C000263368 |

---

### MFS Blended Research Core Equity ETF (Series ID: S000095645)

---

|  |  |  |
|:---|:---|:---|
| Class Name                           | Ticker Symbol | Class ID   |
| MFS Blended Research Core Equity ETF | BRCE          | C000264376 |

---

### MFS Blended Research International Equity ETF (Series ID: S000095646)

---

|  |  |  |
|:---|:---|:---|
| Class Name                                    | Ticker Symbol | Class ID   |
| MFS Blended Research International Equity ETF | BRIE          | C000264377 |

---

### MFS Blended Research Emerging Markets Equity ETF (Series ID: S000097898)

---

|  |  |  |
|:---|:---|:---|
| Class Name                                       | Ticker Symbol | Class ID   |
| MFS Blended Research Emerging Markets Equity ETF | BREE          | C000267408 |

---

## Series and Classes Contracts Data

### MFS Active Core Plus Bond ETF (Series ID: S000085666)

| Class ID   | Class Name                    | Ticker Symbol   |
|:---|:---|:---|
| C000251000 | MFS Active Core Plus Bond ETF | MFSB            |

### MFS Active Growth ETF (Series ID: S000085667)

| Class ID   | Class Name            | Ticker Symbol   |
|:---|:---|:---|
| C000251001 | MFS Active Growth ETF | MFSG            |

### MFS Active Intermediate Muni Bond ETF (Series ID: S000085668)

| Class ID   | Class Name                            | Ticker Symbol   |
|:---|:---|:---|
| C000251002 | MFS Active Intermediate Muni Bond ETF | MFSM            |

### MFS Active International ETF (Series ID: S000085669)

| Class ID   | Class Name                   | Ticker Symbol   |
|:---|:---|:---|
| C000251003 | MFS Active International ETF | MFSI            |

### MFS Active Value ETF (Series ID: S000085670)

| Class ID   | Class Name           | Ticker Symbol   |
|:---|:---|:---|
| C000251004 | MFS Active Value ETF | MFSV            |

### MFS Active Mid Cap ETF (Series ID: S000094824)

| Class ID   | Class Name             | Ticker Symbol   |
|:---|:---|:---|
| C000263368 | MFS Active Mid Cap ETF | MMID            |

### MFS Blended Research Core Equity ETF (Series ID: S000095645)

| Class ID   | Class Name                           | Ticker Symbol   |
|:---|:---|:---|
| C000264376 | MFS Blended Research Core Equity ETF | BRCE            |

### MFS Blended Research International Equity ETF (Series ID: S000095646)

| Class ID   | Class Name                                    | Ticker Symbol   |
|:---|:---|:---|
| C000264377 | MFS Blended Research International Equity ETF | BRIE            |

### MFS Blended Research Emerging Markets Equity ETF (Series ID: S000097898)

| Class ID   | Class Name                                       | Ticker Symbol   |
|:---|:---|:---|
| C000267408 | MFS Blended Research Emerging Markets Equity ETF | BREE            |

![](img_d3db56b59caf4f1.jpg)

SUPPLEMENT TO THE STATEMENT OF ADDITIONAL INFORMATION

*The date of this supplement is December 10, 2025.*

## For the MFS <sup>®</sup> Funds listed below:

---

| | |
|:---|:---|
| MFS<sup>®</sup> ACTIVE CORE PLUS BOND ETF | MFS<sup>®</sup> ACTIVE VALUE ETF |
| MFS<sup>®</sup> ACTIVE GROWTH ETF | MFS<sup>®</sup> BLENDED RESEARCH<sup>®</sup> CORE EQUITY ETF |
| MFS<sup>®</sup> ACTIVE INTERMEDIATE MUNI BOND ETF | MFS<sup>®</sup> BLENDED RESEARCH<sup>®</sup> EMERGING MARKETS EQUITY ETF |
| MFS<sup>®</sup> ACTIVE INTERNATIONAL ETF | MFS<sup>®</sup> BLENDED RESEARCH<sup>®</sup> INTERNATIONAL EQUITY ETF |
| MFS<sup>®</sup> ACTIVE MID CAP ETF |  |

---

#### Effective December 10, 2025, the "Ticker Symbol" table on the cover page is amended to include the following:

---

| | | |
|:---|:---|:---|
| **Fund** | **Ticker Symbol** | **Principal U.S. Listing Exchange** |
| **MFS<sup>®</sup> Active Exchange Traded Funds Trust:** |  |  |
| **MFS<sup>®</sup> Blended Research<sup>®</sup> Emerging Markets Equity ETF** | BREE | New York Stock Exchange LLC ("NYSE") |

---

#### Effective immediately, the following sentences are added to the paragraph following the "Ticker Symbol" table:
In addition, this SAI should be read in conjunction with the Prospectus dated December 10, 2025, for MFS Blended Research Emerging Markets Equity ETF, as may be amended or supplemented from time to time. MFS Blended Research Emerging Markets Equity ETF had not commenced operations as of the fiscal year ended February 28, 2025; therefore, no Financial Statements nor Financial Highlights for such Fund are incorporated by reference into this SAI.

**MFS Blended Research Emerging Markets Equity ETF's fiscal year end is February 28. Certain information for MFS Blended Research Emerging Markets Equity ETF as of February 28, 2025, is not included in this Statement of Additional Information because the Fund had not commenced operations as of February 28, 2025.**

**Effective December 10, 2025, the first paragraph of the sub-section entitled "Organization of the Fund" under the main heading entitled "Management of the Fund" is restated in its entirety as follows:**

MFS Active Core Plus Bond ETF, MFS Active Growth ETF, MFS Active International ETF, MFS Active Intermediate Muni Bond ETF, MFS Active Mid Cap ETF, MFS Active Value ETF, MFS Blended Research Core Equity ETF, MFS Blended Research Emerging Markets Equity ETF, and MFS Blended Research International Equity ETF, each an open-end investment company, are series of MFS Active Exchange Traded Funds Trust, a Massachusetts business trust organized in 2024. MFS Active Growth ETF is a non-diversified fund. MFS Active Core Plus Bond ETF, MFS Active Intermediate Muni Bond ETF, MFS Active International ETF, MFS Active Mid Cap ETF, MFS Active Value ETF, MFS Blended Research Core Equity ETF, MFS Blended Research Emerging Markets Equity ETF, and MFS Blended Research International Equity ETF are diversified funds.

**Effective December 10, 2025, the following is added to the table in the section under the sub-heading "Investment Management Agreement" within the sub-section entitled "Investment Adviser" under the main heading entitled "Management of the Fund":**

---

| | |
|:---|:---|
|  | **Investment Management Fee** |
| MFS Blended Research Emerging Markets Equity ETF | 0.44% |

---

ETF-SAI-COMBINED-SUP-I-121025

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#### Effective December 10, 2025, the following is added to the end of the section entitled "INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM(S) AND FINANCIAL STATEMENTS":
Ernst & Young LLP also serves as the independent registered public accounting firm for MFS Blended Research Emerging Markets Equity ETF, providing audit and related services, tax return review, and assistance in connection with various SEC filings.

MFS Blended Research Emerging Markets Equity ETF had not commenced operations as of the fiscal year ended February 28, 2025; therefore, no Financial Statements nor Financial Highlights for such Fund are incorporated by reference into this SAI.

**Effective December 10, 2025, the following is added to the table entitled "Trustee Compensation Table" under the main heading entitled "APPENDIX B - TRUSTEE COMPENSATION AND COMMITTEES":**

---

| | | | | | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  |  | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** | **Name and Position** |
|  |  | **Interested Trustee** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** | **Independent Trustees** |
| **Aggregate Compensation Paid by Fund** | **Aggregate Compensation Paid by Fund** | Michael W. Roberge | Steven E. Buller | John A. Caroselli | Maureen R. Goldfarb | Peter D. Jones | John P. Kavanaugh | James W. Kilman Jr. | Clarence Otis Jr. | Maryanne L. Roepke | Paula E. Smith<sup>1</sup> | Laurie J. Thomsen | Darrell A. Williams<sup>2</sup> |
| MFS Blended Research Emerging Markets Equity ETF<sup>3</sup> | MFS Blended Research Emerging Markets Equity ETF<sup>3</sup> | Not Applicable | $277 | $277 | $277 | $277 | $277 | $277 | $277 | $277 | $277 | $277 | $277 |
| <sup>1</sup> | Ms. Smith became a Trustee of the Fund on January 1, 2025. | Ms. Smith became a Trustee of the Fund on January 1, 2025. | Ms. Smith became a Trustee of the Fund on January 1, 2025. | Ms. Smith became a Trustee of the Fund on January 1, 2025. | Ms. Smith became a Trustee of the Fund on January 1, 2025. | Ms. Smith became a Trustee of the Fund on January 1, 2025. | Ms. Smith became a Trustee of the Fund on January 1, 2025. |  |  |  |  |  |  |
| <sup>2</sup> | Mr. Williams became a Trustee of the Fund on January 1, 2025. | Mr. Williams became a Trustee of the Fund on January 1, 2025. | Mr. Williams became a Trustee of the Fund on January 1, 2025. | Mr. Williams became a Trustee of the Fund on January 1, 2025. | Mr. Williams became a Trustee of the Fund on January 1, 2025. | Mr. Williams became a Trustee of the Fund on January 1, 2025. | Mr. Williams became a Trustee of the Fund on January 1, 2025. |  |  |  |  |  |  |
| <sup>3</sup> | Estimated amounts for the initial fiscal year of operations. | Estimated amounts for the initial fiscal year of operations. | Estimated amounts for the initial fiscal year of operations. | Estimated amounts for the initial fiscal year of operations. | Estimated amounts for the initial fiscal year of operations. | Estimated amounts for the initial fiscal year of operations. | Estimated amounts for the initial fiscal year of operations. |  |  |  |  |  |  |

---

**Effective December 10, 2025, the first paragraph of the sub-section entitled "Ownership by Trustees and Officers" under the main heading entitled "APPENDIX C — SHARE OWNERSHIP" is restated in its entirety as follows:**

As of November 11, 2025, the Trustees and Officers of the Trust as a group owned of record less than 1% of the Fund's shares. The Board has adopted a policy requiring that each Independent Trustee shall have invested on an aggregate basis, within two years of membership on the Board, an amount equal to his or her prior calendar year's base retainer and meeting attendance fees in shares of the MFS Funds.

**Effective December 10, 2025, the following is added to the second paragraph of the sub-section entitled "Ownership by Trustees and Officers" under the main heading entitled "APPENDIX C — SHARE OWNERSHIP":**

No Trustee owned shares of MFS Blended Research Emerging Markets Equity ETF as of December 31, 2024, because shares of MFS Blended Research Emerging Markets Equity ETF had not been offered for sale as of December 31, 2024.

**Effective December 10, 2025, the third paragraph and table in the sub-section entitled "Control Persons and Principal Holders of Securities" under the main heading entitled "APPENDIX C – SHARE OWNERSHIP" are restated in their entirety as follows:**

Although the Fund does not have the information concerning the beneficial ownership of shares held in the names of DTC Participants, the following identifies the name and percentage ownership of each DTC Participant that owned of record 5% or more of a Fund's outstanding shares as of November 11, 2025.

---

| | | |
|:---|:---|:---|
| **FUND NAME** | **PERCENTAGE<br>FUND**<br>**OWNERSHIP** | **NAME and ADDRESS of INVESTOR** |
| **MFS ACTIVE CORE PLUS BOND ETF** |  |  |
|  | 29.33 | CHARLES SCHWAB & CO INC 211 MAIN ST SAN FRANCISCO CA 94105-1901 |
|  | 22.44 | STATE STREET BANK & TRUST CO 1 CONGRESS ST STE 1 BOSTON MA 02114-2016 |
|  | 16.70 | LPL FINANCIAL LLC 4707 EXECUTIVE DR SAN DIEGO CA 92121-3091 |
|  | 16.03 | NATIONAL FINANCIAL SERVICES LLC 499 WASHINGTON BLVD JERSEY CITY, NJ 07310 |
|  | 13.27 | EDWARD D JONES & CO 12555 MANCHESTER RD SAINT LOUIS MO 63131-3710 |

---

ETF-SAI-COMBINED-SUP-I-121025

------

---

| | | |
|:---|:---|:---|
| **FUND NAME** | **PERCENTAGE<br>FUND**<br>**OWNERSHIP** | **NAME and ADDRESS of INVESTOR** |
| **MFS ACTIVE GROWTH ETF** |  |  |
|  | 46.49 | NATIONAL FINANCIAL SERVICES LLC 499 WASHINGTON BLVD JERSEY CITY, NJ 07310 |
|  | 29.61 | EDWARD D JONES & CO 12555 MANCHESTER RD SAINT LOUIS MO 63131-3710 |
|  | 7.64 | LPL FINANCIAL LLC 4707 EXECUTIVE DR SAN DIEGO CA 92121-3091 |
| **MFS ACTIVE INTERMEDIATE MUNI BOND ETF** |  |  |
|  | 72.58 | STATE STREET BANK & TRUST CO 1 CONGRESS ST STE 1 BOSTON MA 02114-2016 |
|  | 16.31 | CHARLES SCHWAB & CO INC 211 MAIN ST SAN FRANCISCO CA 94105-1901 |
| **MFS ACTIVE INTERNATIONAL ETF** |  |  |
|  | 24.20 | CHARLES SCHWAB & CO INC 211 MAIN ST SAN FRANCISCO CA 94105-1901 |
|  | 20.90 | NATIONAL FINANCIAL SERVICES LLC 499 WASHINGTON BLVD JERSEY CITY, NJ 07310 |
|  | 14.35 | EDWARD D JONES & CO 12555 MANCHESTER RD SAINT LOUIS MO 63131-3710 |
|  | 11.99 | RAYMOND JAMES 880 CARILLON PKWY ST PETERSBURG FL 33716-1102 |
|  | 8.65 | LPL FINANCIAL LLC 4707 EXECUTIVE DR SAN DIEGO CA 92121-3091 |
|  | 6.79 | NORTHERN TRUST COMPANY 50 S LASALLE ST M-11 CHICAGO IL 60603-1003 |
|  | 6.07 | PERSHING LLC 1 PERSHING PLZ JERSEY CITY NJ 07399-0002 |
| **MFS ACTIVE MID CAP ETF** |  |  |
|  | 89.66 | STATE STREET BANK & TRUST CO 1 CONGRESS ST STE 1 BOSTON MA 02114-2016 |
| **MFS ACTIVE VALUE ETF** |  |  |
|  | 25.56 | LPL FINANCIAL LLC 4707 EXECUTIVE DR SAN DIEGO CA 92121-3091 |
|  | 21.85 | STATE STREET BANK & TRUST CO 1 CONGRESS ST STE 1 BOSTON MA 02114-2016 |
|  | 20.30 | NATIONAL FINANCIAL SERVICES LLC 499 WASHINGTON BLVD JERSEY CITY, NJ 07310 |
|  | 11.06 | PERSHING LLC 1 PERSHING PLZ JERSEY CITY NJ 07399-0002 |
|  | 10.37 | EDWARD D JONES & CO 12555 MANCHESTER RD SAINT LOUIS MO 63131-3710 |
| **MFS BLENDED RESEARCH CORE EQUITY ETF** |  |  |
|  | 98.89 | STATE STREET BANK & TRUST CO 1 CONGRESS ST STE 1 BOSTON MA 02114-2016 |
| **MFS BLENDED RESEARCH INTERNATIONAL EQUITY ETF** |  |  |
|  | 92.00 | STATE STREET BANK & TRUST CO 1 CONGRESS ST STE 1 BOSTON MA 02114-2016 |
|  | 5.57 | J.P. MORGAN SECURITIES LLC 4 CHASE METROTECH CTR BROOKLYN NY 11245-0003 |

---

As of November 11, 2025, no shares of MFS Blended Research Emerging Markets Equity ETF were owned because the Fund had not yet commenced operations.

**Effective December 10, 2025, the third paragraph and table in the sub-section entitled "Compensation" under the main heading entitled "APPENDIX D – PORTFOLIO MANAGER(S) " are restated in their entirety as follows:**

With respect to each portfolio manager except Messrs. Brett Fleishman and Chris Sunderland and Mses. Laura Granger and Kate Mead, the performance bonus is based on a combination of quantitative and qualitative factors, generally with more weight given to the former and less weight given to the latter. The quantitative portion is primarily based on the pre-tax performance of accounts managed by the portfolio manager over a range of fixed-length time periods, intended to provide the ability to assess performance over time periods consistent with a full market

ETF-SAI-COMBINED-SUP-I-121025

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cycle and a strategy's investment horizon. The fixed-length time periods include the portfolio manager's full tenure on each Fund/strategy and, when available, 10-, 5-, and 3-year periods. For portfolio managers who have served for less than three years, shorter-term periods, including the one-year period, will also be considered, as will performance in previous roles, if any, held at the firm. Emphasis is generally placed on longer performance periods when multiple performance periods are available. Performance is evaluated across the full set of strategies and portfolios managed by a given portfolio manager, relative to appropriate peer group universes and/or representative indices ("benchmarks"). As of December 31, 2024, the following benchmarks were used to measure the following portfolio managers' performance for the following Funds and/or MFS Funds managed in a substantially similar strategy to the portion of the Funds managed by the portfolio managers, unless otherwise indicated:

---

| | | |
|:---|:---|:---|
| **Fund** | &nbsp;&nbsp;**Portfolio Manager** | **Benchmark(s)** |
| MFS Active Core Plus Bond ETF  | &nbsp;&nbsp;Philipp Burgener | &nbsp;&nbsp;&nbsp;&nbsp;Bloomberg U.S. Aggregate Bond Index |
| MFS Active Core Plus Bond ETF  | &nbsp;&nbsp;Joshua Marston | &nbsp;&nbsp;&nbsp;&nbsp;Bloomberg U.S. Aggregate Bond Index |
| MFS Active Growth ETF | &nbsp;&nbsp;Timothy Dittmer<sup>1</sup> | &nbsp;&nbsp;&nbsp;&nbsp;Russell 1000<sup>®</sup> Growth Index<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Large-Cap Growth Funds<br> Morningstar US Large Growth |
| MFS Active Growth ETF | &nbsp;&nbsp;Eric Fischman | &nbsp;&nbsp;&nbsp;&nbsp;Russell 1000<sup>®</sup> Growth Index<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Large-Cap Growth Funds<br>&nbsp;&nbsp;&nbsp;&nbsp;Morningstar US Large Growth |
| MFS Active Growth ETF | &nbsp;&nbsp;Bradford Mak | &nbsp;&nbsp;&nbsp;&nbsp;Russell 1000<sup>®</sup> Growth Index<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Large-Cap Growth Funds<br> Morningstar US Large Growth |
| MFS Active Intermediate Muni Bond ETF | &nbsp;&nbsp;Jason Kosty | &nbsp;&nbsp;&nbsp;&nbsp;Bloomberg Municipal 1-15 Year Index |
| MFS Active Intermediate Muni Bond ETF | &nbsp;&nbsp;Megan Poplowski | &nbsp;&nbsp;&nbsp;&nbsp;Bloomberg Municipal 1-15 Year Index |
| MFS Active Intermediate Muni Bond ETF | &nbsp;&nbsp;Daniel Streppa | &nbsp;&nbsp;&nbsp;&nbsp;Bloomberg Municipal 1-15 Year Index |
| MFS Active International ETF | &nbsp;&nbsp;Filipe Benzinho | &nbsp;&nbsp;&nbsp;&nbsp;MSCI All Country World (ex-US) Index (net div)<br> Lipper International Large-Cap Core Funds<br>&nbsp;&nbsp;&nbsp;&nbsp;Morningstar Foreign Large Blend |
| MFS Active International ETF | &nbsp;&nbsp;Daniel Ling | &nbsp;&nbsp;&nbsp;&nbsp;MSCI All Country World (ex-US) Index (net div)<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper International Large-Cap Core Funds<br> Morningstar Foreign Large Blend |
| MFS Active International ETF | &nbsp;&nbsp;Harry Purcell<sup>2</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI All Country World (ex-US) Index (net div)<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper International Large-Cap Core Funds<br> Morningstar Foreign Large Blend |
| MFS Active International ETF | &nbsp;&nbsp;Jed Stocks | &nbsp;&nbsp;&nbsp;&nbsp;MSCI All Country World (ex-US) Index (net div)<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper International Large-Cap Core Funds<br>&nbsp;&nbsp;&nbsp;&nbsp;Morningstar Foreign Large Blend |
| &nbsp;&nbsp;MFS Active Mid Cap ETF | &nbsp;&nbsp;Kevin Schmitz<sup>3</sup> | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Russell Midcap<sup>®</sup> Index<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Mid-Cap Core Funds<br>Morningstar US Fund Mid-Cap Blend |
| &nbsp;&nbsp;MFS Active Value ETF | &nbsp;&nbsp;Katherine Cannan | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Russell 1000<sup>®</sup> Value Index<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Large-Cap Value Funds<br>Morningstar US Large Value |
|  | &nbsp;&nbsp;Nevin Chitkara | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Russell 1000<sup>®</sup> Value Index<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Large-Cap Value Funds<br>Morningstar US Large Value |
|  | &nbsp;&nbsp;Thomas Crowley | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Russell 1000<sup>®</sup> Value Index<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Large-Cap Value Funds<br>Morningstar US Large Value |
| &nbsp;&nbsp;MFS Blended Research Core Equity ETF | &nbsp;&nbsp;Matt Krummell<sup>4</sup> | &nbsp;&nbsp;Standard & Poor's 500 Stock Index |
|  | &nbsp;&nbsp;Jim Fallon<sup>4</sup> | &nbsp;&nbsp;Standard & Poor's 500 Stock Index |
|  | &nbsp;&nbsp;Jonathan Sage<sup>4</sup> | &nbsp;&nbsp;Standard & Poor's 500 Stock Index |
|  | &nbsp;&nbsp;Jed Stocks<sup>4</sup> | &nbsp;&nbsp;Standard & Poor's 500 Stock Index |

---

ETF-SAI-COMBINED-SUP-I-121025

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---

| | |
|:---|:---|
| &nbsp;&nbsp;**Fund** | &nbsp;&nbsp;**Benchmark(s)** |
| MFS Blended Research Emerging Markets Equity ETF<br> &nbsp;&nbsp;Jed Stocks<sup>5</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI Emerging Markets Index (net div)<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Emerging Markets Funds<br>&nbsp;&nbsp;&nbsp;&nbsp;Morningstar Diversified Emerging Markets |
| MFS Blended Research Emerging Markets Equity ETF<br> &nbsp;&nbsp;Jim Fallon<sup>5</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI Emerging Markets Index (net div)<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Emerging Markets Funds |
| MFS Blended Research Emerging Markets Equity ETF<br> &nbsp;&nbsp;Matt Krummell<sup>5</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI Emerging Markets Index (net div)<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Emerging Markets Funds |
| MFS Blended Research Emerging Markets Equity ETF<br> &nbsp;&nbsp;Jonathan Sage<sup>5</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI Emerging Markets Index (net div)<br>&nbsp;&nbsp;&nbsp;&nbsp;Lipper Emerging Markets Funds |
| MFS Blended Research International Equity ETF<br> &nbsp;&nbsp;Jed Stocks<sup>4</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI All Country World (ex-US) Index |
| MFS Blended Research International Equity ETF<br> &nbsp;&nbsp;Jim Fallon<sup>4</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI All Country World (ex-US) Index |
| MFS Blended Research International Equity ETF<br> &nbsp;&nbsp;Matt Krummell<sup>4</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI All Country World (ex-US) Index |
| MFS Blended Research International Equity ETF<br> &nbsp;&nbsp;Jonathan Sage <sup>4</sup> | &nbsp;&nbsp;&nbsp;&nbsp;MSCI All Country World (ex-US) Index |

---

<sup>1</sup> Became a portfolio manager of the Fund after the date referenced above; therefore, information is as of June 1, 2025.

<sup>2</sup> Became a portfolio manager of the Fund after the date referenced above; therefore, information is as of May 1, 2025.

<sup>3</sup> The Fund commenced operations after the date referenced above; therefore, information is as of August 26, 2025.

<sup>4</sup> The Fund commenced operations after the date referenced above; therefore, information is as of September 30, 2025.

<sup>5</sup> MFS expects the benchmarks will be used to measure the portfolio manager's performance as of December 10, 2025.

**Effective December 10, 2025, the following is added as the last paragraph in the sub-section entitled "Ownership of Fund Shares" under the main heading entitled "APPENDIX D – PORTFOLIO MANAGER(S)":**

As of December 10, 2025, no portfolio manager owned shares of MFS Blended Research Emerging Markets Equity ETF because the Fund had not yet commenced operations.

**Effective December 10, 2025, the following is added to the table in the sub-section entitled "Other Accounts" under the main heading entitled "APPENDIX D – PORTFOLIO MANAGER(S) ":**

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Fund** | **Category of Accounts Managed** | **Number of Accounts** | **Total Assets** |
| MFS Blended Research Emerging Markets Equity ETF | MFS Blended Research Emerging Markets Equity ETF<br> Jed Stocks<sup>3</sup> (Became a Portfolio Manager of the Fund on December 10, 2025) | Registered Investment Companies<sup>4</sup> | 17 | $10.6 billion |
|  |  | Other Pooled Investment Vehicles | 17 | $3.8 billion |
|  |  | Other Accounts | 35 | $9.6 billion |
|  | Jim Fallon<sup>3</sup> (Became a Portfolio Manager of the Fund on December 10, 2025) | Registered Investment Companies<sup>4</sup> | 16 | $10.0 billion |
|  |  | Other Pooled Investment Vehicles | 17 | $3.8 billion |
|  |  | Other Accounts | 33 | $10.1 billion |
|  | Matt Krummell<sup>3</sup> (Became a Portfolio Manager of the Fund on December 10, 2025) | Registered Investment Companies<sup>4</sup> | 16 | $10.0 billion |
|  |  | Other Pooled Investment Vehicles | 17 | $3.8 billion |
|  |  | Other Accounts | 30 | $9.6 billion |
|  | Jonathan Sage<sup>3</sup> (Became a Portfolio Manager of the Fund on December 10, 2025) | Registered Investment Companies<sup>4</sup> | 19 | $13.4 billion |
|  |  | Other Pooled Investment Vehicles | 19 | $5.2 billion |
|  |  | Other Accounts | 36 | $13.0 billion |

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<sup>3</sup> Account information is as of November 21, 2025.

<sup>4</sup> Does not include the Fund.

ETF-SAI-COMBINED-SUP-I-121025

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#### Effective December 10, 2025, the section under the main heading entitled "APPENDIX I - INVESTMENT RESTRICTIONS" is restated in its entirety as follows:
Fundamental investment restrictions cannot be changed without the approval of a Majority Shareholder Vote. Non-fundamental policies, if any, can be changed without shareholder approval.

MFS Active Core Plus Bond ETF, MFS Active Growth ETF, MFS Active Intermediate Muni Bond ETF, MFS Active International ETF, MFS Active Mid Cap ETF, MFS Active Value ETF, MFS Blended Research Core Equity ETF, MFS Blended Research Emerging Markets Equity ETF, and MFS Blended Research International Equity ETF:

As fundamental investment restrictions, the Fund:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. May borrow money to the extent not prohibited by applicable law.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. May underwrite securities issued by other persons to the extent not prohibited by applicable law.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. May issue senior securities to the extent not prohibited by applicable law.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. May make loans to the extent not prohibited by applicable law.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5. May purchase or sell real estate or commodities to the extent not prohibited by applicable law.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6. May not purchase any securities of an issuer (other than securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities; tax-exempt obligations issued or guaranteed by a U.S. territory or possession, a state or local government, or a political subdivision of any of the foregoing; or securities issued by investment companies) in a particular industry or group of industries if as a result 25% or more of its total assets (taken at market value at the time of purchase) would be invested in securities of issuers whose principal business activities are in the same industry or group of industries.

Except for the Fund's fundamental investment restriction No. 1, these investment restrictions are adhered to at the time of purchase or utilization of assets; a subsequent change in circumstances will not be considered to result in a violation of policy.

For purposes of fundamental investment restriction No. 6, the Fund will consider the stated industry concentration policies of underlying investment companies, to the extent they are known to the Fund, when making investments.

For purposes of fundamental investment restriction No. 6, MFS uses a customized set of industry groups for classifying securities based on classifications developed by third party providers.

For purposes of fundamental investment restriction No. 6, the Fund will look through a private activity municipal bond whose principal and interest payments are derived principally from the assets and revenues of a non-governmental entity in determining the industry classification of the investment.

ETF-SAI-COMBINED-SUP-I-121025

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