Nuveen Municipal Income Fund, Inc. (the Fund) is a diversified closed-end management investment company. The Fund's investment objective is to provide current income exempt from regular federal income tax by investing primarily in a portfolio of municipal obligations issued by state and local government authorities or certain territories of the United States. It invests approximately 80% of its managed assets in municipal securities rated investment grade at the time of investment, or, if they are unrated, are judged by the manager to be of comparable quality. It may invest approximately 20% of its managed assets in municipal securities rated below investment quality or judged by the manager to be of comparable quality. It may invest in inverse floating rate municipal securities, also known as tender option bonds. Nuveen Fund Advisors, LLC is the investment advisor of the Fund. Nuveen Asset Management, LLC is the sub-advisor of the Fund.