Updated Information Regarding Auction Preferred Securities Market Available on MFS Investment Management's Web Site

Business Wire, May 12, 2008

BOSTON -- MFS Investment Management([R]) (MFS([R])) today announced the availability of information on the results of the weekly auctions for the week ending May 9, 2008, that determine the dividend rate payable on the auction rate preferred shares issued by the closed-end funds identified below. The data is posted online at www.mfs.com and can be accessed by clicking on "News & Commentary," then "News Room," then "Closed-End Funds Press Releases." The information pertains to the following MFS closed-end funds:

MFS California Insured Municipal Fund (AMEX: CCA)

MFS High Income Municipal Trust (NYSE: CXE)

MFS High Yield Municipal Trust (NYSE: CMU)

MFS Investment Grade Municipal Trust (NYSE: CXH)

MFS Municipal Income Trust (NYSE: MFM)

MFS manages $184 billion in assets on behalf of more than 5 million individual and institutional investors worldwide as of March 31, 2008. The company traces its origins to 1924 and the creation of America's first mutual fund.

The Trusts are closed-end investment companies. Common shares of the Trusts trade at the current market price, on the NYSE, except that the common shares of the MFS California Insured Municipal Fund, are traded only on the American Stock Exchange. Common shares may trade at a discount to NAV. The auction rate preferred shares of the Trusts are not listed for trading on any exchange and may only be traded in accordance with the by-laws of the applicable Trust.