Exhibit 4(c)

Amendment No. 1 to the Investment Management Agreement

This Amendment No. 1 to the Investment Management Agreement dated as of October 1, 2015 (the “Amendment”) is entered into by and between BlackRock Municipal Bond Fund, Inc., a Maryland corporation (the “Corporation”), on behalf of its series, BlackRock National Municipal Fund (the “Fund”), and BlackRock Advisors, LLC, a Delaware limited liability company (the “Advisor”).

WHEREAS, the Corporation, on behalf of the Fund, and the Advisor have entered into an Investment Management Agreement dated October 27, 2006 (the “Management Agreement”) pursuant to which the Advisor agreed to act as investment adviser to the Fund; and

WHEREAS, the Management Agreement provides that the Corporation, on behalf of the Fund, will pay to the Advisor a monthly fee in arrears at an annual rate equal to the amount set forth in Schedule A thereto; and

WHEREAS, the Management Agreement provides that the Management Agreement may be amended by the parties to the Management Agreement only if such amendment is specifically approved by the vote of the Board of Directors of the Corporation, including a majority of those Directors who are not parties to the Management Agreement or interested persons of any such party cast in person at a meeting called for the purpose of voting on such approval and, where required by the Investment Company Act of 1940, by a vote of a majority of the outstanding voting securities of the Fund; and

WHEREAS, the Board of Directors, including a majority of those Directors who are not interested persons of the Corporation, specifically approved this Amendment at an in-person meeting held on September 10, 2015.

NOW, THEREFORE, the parties hereto, intending to be legally bound, hereby agree as follows:

1. Schedule A of the Management Agreement is hereby amended as set forth on the Schedule A attached hereto with respect to the Fund.

2. Except as otherwise set forth herein, the terms and conditions of the Management Agreement shall remain in full force and effect.

[End of Text]

IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 1 to the Investment Management Agreement to be executed by their officers designated below as of the day and year first written above.

BLACKROCK MUNICIPAL BOND FUND, INC.
By:	/s/ John Perlowski
	Name: John Perlowski
	Title: President and Chief Executive Officer
BLACKROCK ADVISORS, LLC
By:	/s/ Neal J. Andrews
	Name: Neal J. Andrews
	Title: Managing Director

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Schedule A

Investment Advisory Fee

	Rate of Advisory Fee
Aggregate of average daily Net Assets of the three combined Funds	National Fund
First $250 million		0.450	%
In excess of $250 million but not exceeding $400 million		0.425	%
In excess of $400 million but not exceeding $550 million		0.425	%
In excess of $550 million but not exceeding $1.5 billion		0.425	%
In excess of $1.5 billion		0.425	%

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