Report of Independent Registered Public
Accounting Firm

To the Board of Trustees of Master Investment Portfolio
and Investors of the funds listed in Appendix A,
(hereafter referred to as the "Master Portfolios")

In planning and performing our audits of the financial
statements of the Master Portfolios as of and for the
periods ended December 31, 2019, in accordance with the
standards of the Public Company Accounting Oversight
Board (United States) ("PCAOB"), we considered the
Master Portfolios' 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
the 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 Master
Portfolios' internal control over financial reporting.
Accordingly, we do not express an opinion on the
effectiveness of the Master Portfolios' internal control
over financial reporting.

The management of the Master Portfolios 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 master portfolio'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 master portfolio'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 master portfolio; (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 master portfolio are
being made only in accordance with authorizations of
management and directors of the master portfolio; and
(3) provide reasonable assurance regarding prevention or
timely detection of unauthorized acquisition, use or
disposition of a master portfolio'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
master portfolio's annual or interim financial statements
will not be prevented or detected on a timely basis.

Our consideration of the Master Portfolios' 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
over financial reporting that might be material
weaknesses under standards established by the PCAOB.
However, we noted no deficiencies in the Master
Portfolios' internal control over financial reporting and
their operation, including controls over safeguarding
securities, that we consider to be material weaknesses as
defined above as of December 31, 2019.

This report is intended solely for the information and use
of the Board of Trustees of Master Investment Portfolio
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/PricewaterhouseCoopers LLP
Philadelphia, Pennsylvania
February 27, 2020

Appendix A

Active Stock Master Portfolio
International Tilts Master Portfolio
Large Cap Index Master Portfolio
Total International Ex U.S. Index Master Portfolio
U.S. Total Bond Index Master Portfolio
LifePath(r) Dynamic 2025 Master Portfolio
LifePath(r) Dynamic 2030 Master Portfolio
LifePath(r) Dynamic 2035 Master Portfolio
LifePath(r) Dynamic 2040 Master Portfolio
LifePath(r) Dynamic 2045 Master Portfolio
LifePath(r) Dynamic 2050 Master Portfolio
LifePath(r) Dynamic 2055 Master Portfolio
LifePath(r) Dynamic 2060 Master Portfolio
LifePath(r) Dynamic 2065 Master Portfolio*
LifePath(r) Dynamic Retirement Master Portfolio
LifePath(r) Index 2025 Master Portfolio
LifePath(r) Index 2030 Master Portfolio
LifePath(r) Index 2035 Master Portfolio
LifePath(r) Index 2040 Master Portfolio
LifePath(r) Index 2045 Master Portfolio
LifePath(r) Index 2050 Master Portfolio
LifePath(r) Index 2055 Master Portfolio
LifePath(r) Index 2060 Master Portfolio
LifePath(r) Index 2065 Master Portfolio*
LifePath(r) Index Retirement Master Portfolio


* October 30, 2019 (commencement of operations)
through December 31, 2019