# EDGAR Filing Document

**Accession Number:** 0000225635
**File Stem:** 0001193125-23-058158
**Filing Date:** 2023-3
**Character Count:** 4768
**Document Hash:** 377121321615bfc53f6f406f1a06c5ab
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-23-058158.hdr.sgml**: 20230302

**ACCESSION NUMBER**: 0001193125-23-058158

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20230302

**DATE AS OF CHANGE**: 20230302

**EFFECTIVENESS DATE**: 20230302

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BLACKROCK MUNICIPAL BOND FUND, INC.
- **CENTRAL INDEX KEY:** 0000225635
- **IRS NUMBER:** 132896246
- **STATE OF INCORPORATION:** NJ
- **FISCAL YEAR END:** 0630

**FILING VALUES:**
- **FORM TYPE:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 002-57354
- **FILM NUMBER:** 23698973

**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:** MERRILL LYNCH MUNICIPAL BOND FUND INC
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ONE LIBERTY MUNICIPAL BOND FUND INC
- **DATE OF NAME CHANGE:** 19780622

## Series and Classes Contracts Data

### BlackRock Impact Municipal Fund (Series ID: S000075512)

---

|  |  |
|:---|:---|
| Class Name    | Class ID   |
| Investor A    | C000234660 |
| Institutional | C000234661 |
| Class K       | C000234662 |

---

## Series and Classes Contracts Data

### BlackRock Impact Municipal Fund (Series ID: S000075512)

| Class ID   | Class Name    | Ticker Symbol   |
|:---|:---|:---|
| C000234660 | Investor A    |  |
| C000234661 | Institutional |  |
| C000234662 | Class K       |  |

**BLACKROCK MUNICIPAL BOND FUND, INC.** 

**BlackRock Impact Municipal Fund** 

(the "Fund")

**Supplement dated March 2, 2023 (the "Supplement") to the Fund's** 

**Summary Prospectuses and Prospectuses, each dated September 28, 2022** 

**The following changes are made to the Fund's Summary Prospectuses and Prospectuses, as applicable:** 

**The section of the Summary Prospectuses entitled "Key Facts About BlackRock Impact Municipal Fund — Portfolio Managers" and the section of the Prospectuses entitled "Fund Overview — Key Facts About BlackRock Impact Municipal Fund — Portfolio Managers" are deleted in their entirety and replaced with the following:** 

***Portfolio Managers***

---

| | | |
|:---|:---|:---|
| **Name** | **Portfolio Manager of<br>the Fund Since** | **Title** |
| Michael Kalinoski, CFA | 2022 | Director of BlackRock, Inc. |
| Kristi Manidis | 2022 | Director of BlackRock, Inc. |

---

**The section of the Prospectuses entitled "Details About the Fund — How the Fund Invests — About the Portfolio Management Team of the Fund" is deleted in its entirety and replaced with the following:** 

---

| |
|:---|
| &nbsp;&nbsp;&nbsp;**ABOUT THE PORTFOLIO MANAGEMENT TEAM OF THE FUND** |
| &nbsp;&nbsp;&nbsp;The Fund is managed by a team of financial professionals. Michael Kalinoski, CFA, and Kristi Manidis are the portfolio managers and are jointly and primarily responsible for the day-to-day management of the Fund. Please see "Management of the Fund — Portfolio Manager Information" for additional information about the portfolio management team. |

---

**The section of the Prospectuses entitled "Management of the Fund — Portfolio Manager Information" is deleted in its entirety and replaced with the following:** 

***Portfolio Manager Information***

Information regarding the portfolio managers of the Fund is set forth below. Further information regarding the portfolio managers, including other accounts managed, compensation, ownership of Fund shares, and possible conflicts of interest, is available in the Fund's SAI.

------

The Fund is managed by a team of financial professionals. Michael Kalinoski, CFA, and Kristi Manidis are jointly and primarily responsible for the day-to-day management of the Fund.

---

| | | | |
|:---|:---|:---|:---|
| **Portfolio Manager** | **Primary Role** | **Since** | **Title and Recent Biography** |
| Michael Kalinoski, CFA | Jointly and primarily responsible for the day-to-day management of the Fund's portfolio, including setting the Fund's overall investment strategy and overseeing the management of the Fund. | 2022 | Director of BlackRock, Inc. since 2006. |
| Kristi Manidis | Jointly and primarily responsible for the day-to-day management of the Fund's portfolio, including setting the Fund's overall investment strategy and overseeing the management of the Fund. | 2022 | Director of BlackRock, Inc. since 2016; Vice President of BlackRock, Inc. from 2011 to 2015; Associate of BlackRock, Inc. from 2006 to 2010. |

---

**Shareholders should retain this Supplement for future reference.** 

PRO-IMPF-0323SUP