Report of Independent Registered Public Accounting Firm

To the Shareholders of the Funds and Board of Trustees
SEI Institutional Investments Trust:

In planning and performing our audits of the
financial statements of SEI Institutional
Investments Trust, comprised of Large Cap Fund,
Large Cap Disciplined Equity Fund, Large Cap Index
Fund, S&P 500 Index Fund, Extended Market Index
Fund, Small Cap Fund, Small Cap II Fund, Small/Mid
Cap Equity Fund, U.S. Equity Factor Allocation Fund,
U.S. Managed Volatility Fund, Global Managed
Volatility Fund, World Equity Ex-US Fund, Screened
World Equity Ex-US Fund, World Select Equity Fund,
Emerging Markets Equity Fund, Opportunistic Income
Fund, Core Fixed Income Fund, High Yield Bond Fund,
Long Duration Fund, Long Duration Credit Fund, Ultra
Short Duration Bond Fund, Emerging Markets Debt
Fund, Real Return Fund, Limited Duration Bond Fund,
Intermediate Duration Credit Fund, Dynamic Asset
Allocation Fund, and Multi-Asset Real Return Fund
(collectively, the Funds) as of and for the year
ended May 31, 2023, in accordance with the standards
of the Public Company Accounting Oversight Board
(United States), 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 the Funds' 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.

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
the 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 Public Company
Accounting Oversight Board (United States). However,
we noted no deficiencies in the Funds' internal
control over financial reporting and its operation,
including controls over safeguarding securities,
that we consider to be a material weakness as
defined above as of May 31, 2023.

This report is intended solely for the information
and use of the management and the Board of 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/ KPMG LLP

Philadelphia, Pennsylvania
July 27, 2023