CENTENNIAL MONEY MARKET TRUST
                Supplement dated January 1, 1999 to the
                   Prospectus dated October 30, 1998


The Prospectus is changed as follows:

1. The second  paragraph in the section entitled "Fees and Expenses" on page A-2
of the Prospectus is deleted and replaced with:

      The annual rates applicable to Government Trust are as follows:  0.500% of
the first $250  million of net  assets;  0.475% of the next $250  million of net
assets;  0.450% of the next $250 million of net assets;  0.425% of the next $250
million of net assets; and 0.400% of the next $250 million of net assets; 0.375%
of the next $250 million of net assets and 0.350% of net asset in excess of $1.5
billion. The annual rates applicable to Tax Exempt Trust are as follows:  0.500%
of the first $250 million of net assets;  0.475% of the next $250 million of net
assets;  0.450% of the next $250 million of net assets;  0.425% of the next $250
million of net assets;  0.400% of the next $250 million of net assets; 0.375% of
the next $250  million  of net  assets;  0.350% of the next $500  million of net
assets and 0.325% of net assets in excess of $2 billion. Furthermore,  under Tax
Exempt  Trust's  Agreement,  when the value of Tax Exempt  Trust's net assets is
less than $1.5  billion,  the annual fee payable to the Manager shall be reduced
by $100,000  based on average net assets  computed daily and paid monthly at the
annual  rates,  but in no event  shall the  annual  fee be less than $0. See the
Statement  of  Additional  Information  for  an  explanation  of  the  Manager's
reimbursement  arrangement  for  the  Trusts  set  forth  in  their  Agreements.
"Investment  Management Services" in the Appendix to the Statement of Additional
Information contains more complete information about the Agreements, including a
discussion  of  expense  arrangements,  and a  description  of  the  exculpation
provisions and portfolio transactions.

January 1, 1999                                               PS0150.004