December 28, 1998
Supplement to Prospectus for
Pioneer Short-Term Income Trust (Class A and B Shares)
dated March 30, 1998
Pioneer Short-Term Income Trust (Class Y Shares)
dated April 9, 1998
The following information supplements the corresponding section of the
Prospectus. Please consult the Prospectus for the full text of the revised
section.
INVESTMENT POLICIES
Quality
Under normal circumstances, the Trust invests at least 90% of its total assets
in debt securities that are issued or guaranteed by the U.S. Government or its
agencies or instrumentalities, debt securities that are rated in the four
highest grades by the nationally recognized securities rating organizations or
unrated securities determined by Pioneer Investment Management, Inc., ("Pioneer
Investments") the Trust's investment adviser, to be of comparable quality and
comparably rated commercial paper and cash and cash equivalents. No more than
10% of the Trust's total assets may be invested in securities that are rated
below investment grade.
Maturity
The average life of the Trust's portfolio will be in the 1 to 5 year range, and
the average life of any single issuer will be no greater than 10 years.
Asset Segregation
The Investment Company Act of 1940 (the "1940 Act") requires that the Trust
segregate assets in connection with certain types of transactions. If the Trust
enters into a transaction requiring segregation, the custodian or Pioneer
Investments will segregate liquid assets in an amount required to comply with
the 1940 Act. Such segregated assets will be valued at market daily. If the
aggregate value of such segregated assets declines below the aggregate value
required to satisfy the 1940 Act, additional liquid assets will be segregated.
MANAGEMENT OF THE FUND
As of December 2, 1998, day-to-day management of the Trust is the responsibility
of a team of fixed income portfolio managers and analysts supervised by Sherman
B. Russ and Kenneth J. Taubes. Mr. Russ and Mr. Taubes are jointly responsible
for overseeing Pioneer Investments' U.S. and global fixed income team. Mr. Russ
is a senior vice president of Pioneer Investments. He joined Pioneer Investments
in 1983 and has been an investment professional since 1962. Mr. Taubes joined
Pioneer Investments as a senior vice president in September 1998 and has been an
investment professional since 1986. Prior to joining Pioneer Investments, Mr.
Taubes had served since 1991 as a senior vice president and senior portfolio
manager for several Putnam Investments institutional accounts and mutual funds.
1298-5971
(C) Pioneer Funds Distributor, Inc.
