Supplement to the Current Prospectus

MFS(R)  Municipal Income Fund - Class A1 & B1 Shares

Effective  June 1, 2008,  the following  paragraph in the  sub-section  entitled
"Exchange  Privilege"  under the main  heading  "How to  Purchase,  Redeem,  and
Exchange Shares" is deleted in its entirety:

Certain  qualified  retirement plans may make certain  exchanges between the MFS
funds  and  the  MFS  Fixed  Fund.  Contact  MFSC  for  information   concerning
transactions involving the MFS Fixed Fund.

In the current prospectus and in any supplements  thereto dated prior to June 1,
2008, any references to the "MFS Fixed Fund" are hereby deleted.


                  The date of this supplement is June 1, 2008.