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<PAGE> PAGE 2
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<PAGE> PAGE 3
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<PAGE> PAGE 5
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<PAGE> PAGE 7
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SIGNATURE ROBERT P. NAULT
TITLE ASST. SECRETARY
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</TABLE>
To the Board of Trustees of
Pioneer Cash Reserves Fund:
In planning and performing our audit of the financial statements of Pioneer Cash
Reserves Fund for the year ended December 31, 1997, we considered its internal
control structure, including procedures for safeguarding securities, in order to
determine our auditing procedures for the purpose of expressing our opinion on
the financial statements and to comply with the requirements of Form N-SAR, not
to provide assurance on the internal control structure.
The management of Pioneer Cash Reserves Fund is responsible for establishing and
maintaining an internal control structure. In fulfilling this responsibility,
estimates and judgments by management are required to assess the expected
benefits and related costs of internal control structure policies and
procedures. Generally, controls that are relevant to an audit pertain to the
entity's objective of preparing financial statements for external purposes that
are fairly presented in conformity with generally accepted accounting
principles. Those controls include the safeguarding of assets against
unauthorized acquisition, use or disposition.
Because of inherent limitations in any internal control structure, errors or
irregularities may occur and may not be detected. Also, projection of any
evaluation of the structure to future periods is subject to the risk that it may
become inadequate because of changes in conditions or that the effectiveness of
the design and operation may deteriorate.
Our consideration of the internal control structure would not necessarily
disclose all matters in the internal control structure that might be material
weaknesses under standards established by the American Institute of Certified
Public Accountants. A material weakness is a condition in which the design or
operation of the specific internal control structure elements does not reduce to
a relatively low level the risk that errors or irregularities in amounts that
would be material in relation to the financial statements being audited may
occur and not be detected within a timely period by employees in the normal
course of performing their assigned functions. However, we noted no matters
involving the internal control structure, including controls over safeguarding
securities, that we consider to be material weaknesses as defined above as of
December 31, 1997.
This report is intended solely for the information and use of management and the
Securities and Exchange Commission.
/s/ Arthur Andersen LLP
ARTHUR ANDERSEN LLP
Boston, Massachusetts
February 2, 1998
