Report of Independent Registered Public Accounting Firm

To the Shareholders and Board of Trustees of
Pioneer Series Trust VI:

In planning and performing our audit of the financial statements of Pioneer
Flexible Opportunities Fund and Pioneer Floating Rate Fund (the "Funds")
(two funds constituting Pioneer Series Trust VI) as of and for the year
ended October 31, 2019, 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 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
U.S. 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
U.S. 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 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 October 31, 2019.

This report is intended solely for the information and use of management
and the Board of Trustees of Pioneer Series Trust VI, 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/ ERNST& YOUNG LLP


Boston, Massachusetts
December 20, 2019