Western Asset Municipal High Income Fund Inc. is a closed ended fixed income mutual fund launched and managed by Legg Mason Partners Fund Advisor, LLC. It is co-managed by Western Asset Management Company. The fund invests in the fixed income markets of the United States. It invests primarily in intermediate and long-term municipal debt securities issued by state and local governments including U.S. territories and possessions, political subdivisions, agencies and public authorities. The fund seeks to invest in investment grade debt securities rated in one of the four highest rating categories by a nationally recognized statistical rating organization to create its portfolio. It benchmarks the performance of its portfolio against the Lehman Brothers Municipal Bond Index. The fund was formerly known as Municipal High Income Fund Inc. Western Asset Municipal High Income Fund Inc. was formed on November 28, 1988 and is domiciled in the United States.