# EDGAR Filing Document

**Accession Number:** 0000883412
**File Stem:** 0001193125-25-238646
**Filing Date:** 2025-10
**Character Count:** 3626
**Document Hash:** ccafc3193ecded3c7bcd9411d784423e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-238646.hdr.sgml**: 20251014

**ACCESSION NUMBER**: 0001193125-25-238646

**CONFORMED SUBMISSION TYPE**: 424B3

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20251014

**DATE AS OF CHANGE**: 20251014

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BLACKROCK MUNIYIELD QUALITY FUND III, INC.
- **CENTRAL INDEX KEY:** 0000883412

**ORGANIZATION NAME:**
- **EIN:** 223165131
- **FISCAL YEAR END:** 1031

**FILING VALUES:**
- **FORM TYPE:** 424B3
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-288718
- **FILM NUMBER:** 251390631

**BUSINESS ADDRESS:**
- **STREET 1:** 100 BELLEVUE PARKWAY
- **CITY:** WILMINGTON
- **STATE:** DE
- **ZIP:** 19809
- **BUSINESS PHONE:** 800-441-7762

**MAIL ADDRESS:**
- **STREET 1:** 100 BELLEVUE PARKWAY
- **CITY:** WILMINGTON
- **STATE:** DE
- **ZIP:** 19809

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BLACKROCK MUNIYIELD QUALITY FUND III, INC
- **DATE OF NAME CHANGE:** 20101109

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BLACKROCK MUNIYIELD INSURED FUND, INC
- **DATE OF NAME CHANGE:** 20070612

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MUNIYIELD INSURED FUND INC
- **DATE OF NAME CHANGE:** 19920717

**Filed Pursuant to Rule 424(b)(3)** 

**Registration File No.: 333-288718** 

**BLACKROCK MUNIVEST FUND II, INC.** 

**BLACKROCK MUNIYIELD MICHIGAN QUALITY FUND, INC.** 

**BLACKROCK MUNIVEST FUND, INC.** 

**BLACKROCK MUNIYIELD QUALITY FUND III, INC.** 

**Important Information Regarding the Joint Proxy Statement/Prospectus, dated September 4, 2025 for BlackRock MuniVest Fund II, Inc. ("MVT"), BlackRock MuniYield Michigan Quality Fund, Inc. ("MIY"), BlackRock MuniVest Fund, Inc. ("MVF") and BlackRock MuniYield Quality Fund III, Inc. ("MYI" or the "Acquiring Fund")** 

**The following changes are made to the Joint Proxy Statement/Prospectus:** 

The Section of the Joint Proxy Statement/Prospectus entitled "Voting Information and Requirements – Voting Requirement for Proposal 2: The Issuance of Acquiring Fund Common Shares" is deleted in its entirety and replaced with the following information:

**Voting Requirement for Proposal 2: The Issuance of Acquiring Fund Common Shares** 

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| | |
|:---|:---|
| **Proposals** | **Required Approval of<br>Shareholders** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; *Proposal 2(A)*: The common shareholders and VRDP Holders of the Acquiring Fund are being asked to vote as a single class on a proposal to approve the MVT Issuance. | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Majority of votes entitled to be cast present at the Special Meeting or represented by proxy |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; *Proposal 2(B)*: The common shareholders and VRDP Holders of the Acquiring Fund are being asked to vote as a single class on a proposal to approve the MIY Issuance. | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Majority of votes entitled to be cast present at the Special Meeting or represented by proxy |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; *Proposal 2(C)*: The common shareholders and VRDP Holders of the Acquiring Fund are being asked to vote as a single class on a proposal to approve the MVF Issuance. | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Majority of votes entitled to be cast present at the Special Meeting or represented by proxy. |

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All other references in the Joint Proxy Statement/Prospectus and the accompanying exhibits referencing the vote requirement for shareholders to approve Proposals 2(A), 2(B) and 2(C) are hereby revised and restated to reflect the vote requirements stated in the table above.