Report of Independent Registered Public Accounting
Firm

To the Shareholders and
Board of Directors of Pioneer Trust Series IV:
In planning and performing our audit of the financial
statements of Pioneer Trust Series IV (the Company)
(comprised of Pioneer Classic Balanced Fund, Pioneer
Government Income Fund, and Pioneer Multi-Asset
Income Fund) (the Funds) as of and for the year ended
July 31, 2012, in accordance with the standards of the
Public Company Accounting Oversight Board (United
States), we considered the Company's 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-SAR, but not for the purpose
of expressing an opinion on the effectiveness of the
Company's internal control over financial reporting.
Accordingly, we express no such opinion.
The management of the Company 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 Company's 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 Company's
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 July 31, 2012.
This report is intended solely for the information and use
of management and the Board of Trustees of Pioneer
Trust Series IV and the Securities and Exchange
Commission and is not intended to be and should not be
used by anyone other than these specified parties.



Ernst & Young LLP
Boston, MA

September 25, 2012