Articles Supplementary Reclassifying Shares of Common Stock

BLACKROCK MUNICIPAL BOND FUND, INC.

/s/ Janey Ahn

/s/ John M. Perlowski

John M. Perlowski

President and Chief Executive Officer

BLACKROCK MUNICIPAL BOND FUND, INC., a Maryland corporation (the “Corporation”), hereby certifies to the State Department of Assessments and Taxation of the State of Maryland that:

FIRST: The Corporation is registered as an open-ended company under the Investment Company Act of 1940, as amended, with the authority to issue Seven Billion Five Hundred Twenty-Five Million (7,525,000,000) shares of capital stock as follows:


Series and Classes		Number of Authorized Shares

BlackRock National Municipal Fund
Investor A Common Stock		800,000,000
Investor C Common Stock		375,000,000
Investor C1 Common Stock		375,000,000
Institutional Common Stock		800,000,000
Class K Common Stock		1,350,000,000
Service Common Stock		375,000,000
BlackRock Short-Term Municipal Fund
Investor A Common Stock		150,000,000
Investor A1 Common Stock		150,000,000
Investor C Common Stock		150,000,000
Institutional Common Stock		150,000,000
Class K Common Stock		150,000,000
Service Common Stock		150,000,000
BlackRock High Yield Municipal Fund
Investor A Common Stock		100,000,000
Investor C Common Stock		100,000,000
Institutional Common Stock		350,000,000
Class K Common Stock		2,000,000,000

Total:		7,525,000,000

All shares of all classes of the capital stock of the Corporation have a par value of Ten Cents ($0.10) per share and an aggregate par value of Seven Hundred Fifty-Two Million Five Hundred Thousand Dollars ($752,500,000).

SECOND: Pursuant to authority expressly vested in the Board of Directors of the Corporation by Section 2-105(c) of the Maryland General Corporation Law and the Corporation’s charter, the Board of Directors hereby reclassifies Investor C1 Common Stock of BlackRock National Municipal Fund as authorized but unissued shares of the Corporation’s common stock, par value Ten Cents ($0.10) per share, without designation as to class or series.

THIRD: After the reclassification of authorized shares of capital stock of the Corporation set forth herein, the Corporation will have the authority to issue Seven Billion Five Hundred Twenty-Five Million (7,525,000,000) shares of capital stock as follows:


Series and Classes		Number of Authorized Shares

BlackRock National Municipal Fund
Investor A Common Stock		800,000,000
Investor C Common Stock		375,000,000
Institutional Common Stock		800,000,000
Class K Common Stock		1,350,000,000
Service Common Stock		375,000,000
BlackRock Short-Term Municipal Fund
Investor A Common Stock		150,000,000
Investor A1 Common Stock		150,000,000
Investor C Common Stock		150,000,000
Institutional Common Stock		150,000,000
Class K Common Stock		150,000,000
Service Common Stock		150,000,000
BlackRock High Yield Municipal Fund
Investor A Common Stock		100,000,000
Investor C Common Stock		100,000,000
Institutional Common Stock		350,000,000
Class K Common Stock		2,000,000,000

Total:		7,150,000,000

The remainder of the authorized capital stock of the Corporation, Three Hundred Seventy-Five Million (375,000,000) shares, is not designated or classified as to any class or series. All shares of capital stock of the Corporation will have a par value of Ten Cents ($0.10) per share and an aggregate par value of Seven Hundred Fifty-Two Million Five Hundred Thousand Dollars ($752,500,000).

FOURTH: All of the shares of the Corporation’s capital stock continue to have the same preferences, conversion and other rights, voting powers, restrictions, limitations as to dividends, qualifications, and terms and conditions of redemption as currently set forth in the Corporation’s charter.

IN WITNESS WHEREOF, BLACKROCK MUNICIPAL BOND FUND, INC. has caused these Articles Supplementary to be signed in its name and on its behalf by the person named below who acknowledges that these Articles Supplementary are the act of the Corporation and that, as to all matters and facts required to be verified under oath and to the best of his knowledge, information and belief under the penalties of perjury, the matters and facts set forth herein are true in all material respects, as of this 20^th day of April 2020.