REPORT OF INDEPENDENT REGISTERED PUBLIC
ACCOUNTING FIRM

TO THE SHAREHOLDERS OF BLACKROCK HIGH
YIELD MUNICIPAL FUND, BLACKROCK NATIONAL
MUNICIPAL FUND, BLACKROCK SHORT-TERM
MUNICIPAL FUND, AND BLACKROCK NEW YORK
MUNICIPAL OPPORTUNITIES FUND AND TO THE
BOARD OF DIRECTORS/TRUSTEES OF
BLACKROCK MUNICIPAL BOND FUND, INC. AND
BLACKROCK MULTI-STATE MUNICIPAL SERIES
TRUST:
In planning and performing our audits of the financial
statements of BlackRock High Yield Municipal Fund,
BlackRock National Municipal Fund, and BlackRock Short-
Term Municipal Fund of BlackRock Municipal Bond Fund,
Inc., and BlackRock New York Municipal Opportunities Fund
of BlackRock Multi-State Municipal Series Trust (the
"Funds"), as of and for the year ended June 30, 2020, in
accordance with the standards of the Public Company
Accounting Oversight Board (United States) (PCAOB), we
considered the Funds' internal control over financial reporting,
including controls over safeguarding securities, as a basis for
designing our auditing procedures for the purpose of
expressing our opinion on financial statements and to comply
with the requirements of Form N-CEN, but not for the purpose
of expressing an opinion on the effectiveness of the Funds'
internal control over financial reporting. Accordingly, we
express no such opinion.
The management of the Funds is responsible for establishing
and maintaining effective internal control over financial
reporting. In fulfilling this responsibility, estimates and
judgments by management are required to assess the expected
benefits and related costs of controls. A company's internal
control over financial reporting is a process designed to
provide reasonable assurance regarding the reliability of
financial reporting and the preparation of financial statements
for external purposes in accordance with generally accepted
accounting principles. A company's internal control over
financial reporting includes those policies and procedures that
(1) pertain to the maintenance of records that, in reasonable
detail, accurately and fairly reflect the transactions and
dispositions of the assets of the company; (2) provide
reasonable assurance that transactions are recorded as
necessary to permit preparation of financial statements in
accordance with generally accepted accounting principles, and
that receipts and expenditures of the company are being made
only in accordance with authorizations of management and
directors of the company; and (3) provide reasonable
assurance regarding prevention or timely detection of
unauthorized acquisition, use, or disposition of a company's
assets that could have a material effect on the financial
statements.
Because of its inherent limitations, internal control over
financial reporting may not prevent or detect misstatements.
Also, projections of any evaluation of effectiveness to future
periods are subject to the risk that controls may become
inadequate because of changes in conditions or that the degree
of compliance with the policies or procedures may deteriorate.
A deficiency in internal control over financial reporting exists
when the design or operation of a control does not allow
management or employees, in the normal course of
performing their assigned functions, to prevent or detect
misstatements on a timely basis. A material weakness is a
deficiency, or a combination of deficiencies, in internal
control over financial reporting, such that there is a reasonable
possibility that a material misstatement of the company's
annual or interim financial statements will not be prevented or
detected on a timely basis.
Our consideration of the Funds' internal control over financial
reporting was for the limited purpose described in the first
paragraph and would not necessarily disclose all deficiencies
in internal control that might be material weaknesses under
standards established by the PCAOB. However, we noted no
deficiencies in the Funds' internal control over financial
reporting and its operation, including controls for safeguarding
securities that we consider to be a material weakness, as
defined above, as of June 30, 2020.
This report is intended solely for the information and use of
management and Board of Directors/Trustees of the Funds and
the Securities and Exchange Commission and is not intended
to be and should not be used by anyone other than these
specified parties.

/s/ Deloitte & Touche LLP
Boston, Massachusetts
August 21, 2020