<PAGE>
MFS MUNICIPAL HIGH INCOME FUND
Supplement to the June 1, 1996 Prospectus
Effective October 1, 1996, dividends will be declared by the Fund on a daily
basis so that each business day will be a record date. Dividends will continue
to be distributed to shareholders on a monthly basis. Shareholders may elect to
receive dividend distributions in either cash or additional shares.
Reinvestments (net of any tax withholding) will be made in additional full and
fractional shares at the net asset value in effect at the close of business on
the last business day of the month.
The date of this Supplement is September 15, 1996.
