SUPPLEMENT TO THE CLASS A PROSPECTUS AND THE STATEMENT OF ADDITIONAL INFORMATION

                        CREDIT SUISSE MUNICIPAL BOND FUND

THE FOLLOWING INFORMATION SUPERSEDES CERTAIN INFORMATION IN THE FUND'S CLASS A
PROSPECTUS AND STATEMENT OF ADDITIONAL INFORMATION.

THE FIRST FOOTNOTE IMMEDIATELY FOLLOWING THE "FEES AND FUND EXPENSES" TABLE,
WHICH APPEARS ON PAGE 8 OF THE PROSPECTUS, IS REPLACED WITH THE FOLLOWING:

1    The maximum sales charge imposed is reduced for larger purchases. Purchases
     of $250,000 or more are not subject to an initial sales charge but may be
     subject to a .50% CDSC (Contingent Deferred Sales Charge) on redemptions
     made within 12 months of purchase. See "Other Shareholder Information."

THE FIRST FOOTNOTE IMMEDIATELY FOLLOWING THE "INITIAL SALES CHARGE" TABLE, WHICH
APPEARS ON PAGE 24 OF THE PROSPECTUS, IS REPLACED WITH THE FOLLOWING:

*    On purchases of $250,000 or more, there is no initial sales charge although
     there could be a .50% Limited CDSC (as described under "Class A Limited
     CDSC" below).

THE FIRST PARAGRAPH UNDER THE "CLASS A LIMITED CDSC" SECTION, WHICH APPEARS ON
PAGE 26 OF THE PROSPECTUS, IS REPLACED WITH THE FOLLOWING:

A Limited Contingent Deferred Sales Charge ("Limited CDSC") will be imposed by
the fund upon redemptions of Class A shares made within 12 months of purchase,
if such purchases were made at net asset value on a purchase of $250,000 or more
and the distributor paid any commission to the financial representative. The
Limited CDSC also applies to redemptions of shares of other funds into which
such Class A shares are exchanged. Any Limited CDSC charged on a redemption of
exchanged-for-fund shares is computed in the manner set forth in the
exchanged-for-fund's prospectus. You will not have to pay a limited CDSC when
you redeem fund shares that you purchased in exchange for shares of another
fund, if you paid a sales charge when you purchased that other fund's shares.

THE FIRST SENTENCE IN THE SECOND PARAGRAPH UNDER THE "CLASS A LIMITED CDSC"
SECTION, WHICH APPEARS ON PAGE 26 OF THE PROSPECTUS, IS REPLACED WITH THE
FOLLOWING:

The Limited CDSC will be paid to the distributor and will be equal to the lesser
of .50% of:

     -    the net asset value at the time of purchase of the Class A shares
          being redeemed; or

     -    the net asset value of such Class A shares at the time of redemption.

ANY CONTRARY INFORMATION IN THE FUND'S STATEMENT OF ADDITIONAL INFORMATION IS
SUPERSEDED.

Dated: February 28, 2003                                           CSMBA-16-0203
                                                                        2003-009