The MFS Intermediate High Income Fund operates as a closed-end mutual fund, managed by Massachusetts Financial Services Company, specializing in fixed-income investments. Its portfolio predominantly allocates capital within the United States' fixed income markets, with a particular emphasis on high-income debt instruments. For performance evaluation, the fund benchmarks its results against the Barclays U.S. High-Yield Corporate 2% Issuer Capped Index. Established on July 21, 1988, and based in the United States, it was formerly known as the Colonial Intermediate High Income Fund.