# EDGAR Filing Document

**Accession Number:** 0000225604
**File Stem:** 0001741773-25-002475
**Filing Date:** 2025-6
**Character Count:** 4110
**Document Hash:** 56fe73057795bc8e2df9794c08039633
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001741773-25-002475.hdr.sgml**: 20250604

**ACCESSION NUMBER**: 0001741773-25-002475

**CONFORMED SUBMISSION TYPE**: 497J

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20250604

**DATE AS OF CHANGE**: 20250604

**EFFECTIVENESS DATE**: 20250604

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MFS SERIES TRUST III
- **CENTRAL INDEX KEY:** 0000225604

**ORGANIZATION NAME:**
- **EIN:** 046414785
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0131

**FILING VALUES:**
- **FORM TYPE:** 497J
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 002-60491
- **FILM NUMBER:** 251022275

**BUSINESS ADDRESS:**
- **STREET 1:** 111 HUNTINGTON AVENUE
- **STREET 2:** 21ST FLOOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199
- **BUSINESS PHONE:** 18006372929

**MAIL ADDRESS:**
- **STREET 1:** 111 HUNTINGTON AVENUE
- **STREET 2:** 21ST FLOOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS SERIES TRUST III /MA
- **DATE OF NAME CHANGE:** 19940411

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS HIGH INCOME FUND
- **DATE OF NAME CHANGE:** 19930408

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MASSACHUSETTS FINANCIAL HIGH INCOME TRUST
- **DATE OF NAME CHANGE:** 19920703

## Series and Classes Contracts Data

### MFS High Income Fund (Series ID: S000002427)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000006471 | A            | MHITX           |
| C000006472 | R4           | MHIJX           |
| C000006476 | B            | MHIBX           |
| C000006477 | C            | MHICX           |
| C000006478 | I            | MHIIX           |
| C000006480 | R1           | MHIGX           |
| C000006482 | R2           | MIHRX           |
| C000006483 | R3           | MHIHX           |
| C000116932 | R6           | MHIKX           |

### MFS Global High Yield Fund (Series ID: S000002428)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000006484 | A            | MHOAX           |
| C000006485 | B            | MHOBX           |
| C000006486 | C            | MHOCX           |
| C000006487 | I            | MHOIX           |
| C000064677 | R1           | MHORX           |
| C000064678 | R2           | MHOSX           |
| C000064679 | R3           | MHOTX           |
| C000064680 | R4           | MHOUX           |
| C000064681 | R6           | MHOVX           |

### MFS Municipal High Income Fund (Series ID: S000002429)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000006488 | A            | MMHYX           |
| C000006489 | B            | MMHBX           |
| C000006490 | C            | MMHCX           |
| C000103072 | I            | MMIIX           |
| C000191232 | R6           | MMHKX           |

### MFS High Yield Pooled Portfolio (Series ID: S000038262)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000118060 | Fund Shares  | HYPPX           |

#### 111 Huntington Avenue, Boston, Massachusetts 02199

#### 617-954-5000
June 4, 2025

#### VIA EDGAR
United States Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549

 **Re: MFS<sup>®</sup> Series Trust III (the "Trust") (File Nos. 2-60491 and 811-2794) on behalf of MFS<sup>®</sup> Global High Yield Fund, MFS<sup>®</sup> High Income Fund, MFS<sup>®</sup> High Yield Pooled Portfolio, and MFS<sup>®</sup> Municipal High Income Fund (the "Funds")** 

Ladies and Gentlemen:

Pursuant to Rule 497(j) under the Securities Act of 1933, as amended, please accept this letter on behalf of the Trust as certification that the Prospectuses and the combined Statement of Additional Information for the Funds do not differ from those contained in Post-Effective Amendment No. 74 (the "Amendment") to the Trust's Registration Statement on Form N-1A. The Amendment was filed electronically on May 29, 2025.

Please call the undersigned at 617-954-5655 or Danielle Jaffe at 617-954-5546 with any questions you may have.

Sincerely,

WILLIAM B. WILSON

William B. Wilson

Assistant Vice President and Senior Counsel

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