<PAGE>
SAFECO COMMON STOCK TRUST
SAFECO TAX-EXEMPT BOND TRUST
SAFECO TAXABLE BOND TRUST
SAFECO MANAGED BOND TRUST
SAFECO MONEY MARKET TRUST
SUPPLEMENT TO THE ADVISOR CLASS STATEMENT OF ADDITIONAL
INFORMATION DATED APRIL 30, 1999
SUPPLEMENT DATED SEPTEMBER 1, 1999
THE FOLLOWING INFORMATION SUPPLEMENTS THE FOURTH PARAGRAPH FOLLOWING THE CAPTION
"DISTRIBUTION ARRANGEMENTS" ON PAGE 95-96 OF THE ADVISOR CLASS STATEMENT OF
ADDITIONAL INFORMATION:
In addition to the commissions and concessions described in the
prospectus, SAFECO Securities may, at its expense, pay additional
commissions or promotional incentives to dealers that sell shares of the
Funds. Such additional commissions or incentives may be offered only to
dealers which satisfy certain sales volume/growth criteria, or which meet
other criteria SAFECO Securities establishes from time to time. In
connection with such a marketing relationship, SAFECO Securities has
agreed to pay WM Financial Services, Inc. additional compensation in the
amount of .25% on new sales, other than sales of those Class A Shares
which are sold at net asset value and shares of the Money Market Fund for
which .10% in additional compensation will be paid.
