Report of Independent Registered Public Accounting
Firm

To the Board of Trustees and Shareholders of
Thornburg Investment Trust

In planning and performing our audits of the financial
statements of the funds listed in Appendix A (constituting
Thornburg Investment Trust, hereafter collectively
referred to as the "Funds") as of and for the year ended
September 30, 2018, 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 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 Funds' internal control over financial
reporting.  Accordingly, we do not express an opinion on
the effectiveness of the Funds' internal control over
financial reporting.

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 over financial reporting
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 over
safeguarding securities, that we consider to be material
weaknesses as defined above as of September 30,
2018.

This report is intended solely for the information and use
of the Board of Trustees of Thornburg Investment Trust
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
New York, New York
November 21, 2018