Western Asset Municipal High Income Fund Inc. is a diversified, closed-end management investment company. The Fund seeks high current income exempt from federal income taxes. The Fund invests primarily in intermediate and long-term municipal debt securities issued by state and local governments, including the United States territories and possessions, political subdivisions, agencies and public authorities. The Fund may invest in municipal obligations of any maturity. The Fund may invest up to 100% of its assets in municipal obligations rated below investment grade. The Fund may invest in non-publicly traded municipal securities, zero-coupon municipal obligations and non-appropriation or other municipal lease obligations. The Fund invests in various sectors, such as transportation, housing, healthcare, industrial, power, and water and sewer sectors. Legg Mason Partners Fund Advisor, LLC is the Fund's investment manager and Western Asset Management Company is the Fund's sub advisor.