Blackrock Municipal Income Investment Trust Reports Earnings Results for the Half Year Ended January 31, 2021

BlackRock Municipal Income Investment Trust (the Trust) is a non-diversified, closed-end management investment company. The Trust's investment objective is to provide current income exempt from regular federal income tax and Florida intangible personal property tax. The Trust seeks to achieve its investment objective by investing at least 80% of its assets in municipal bonds exempt from federal income taxes and Florida intangible personal property tax. The Trust invests at least 80% of its assets in municipal bonds that are investment grade quality at the time of investment. The Trust may invest directly in such securities or synthetically through the use of derivatives. The Trust invests in various sectors, such as county/city/special district/school district, state, health, utilities, transportation, education, corporate and housing. BlackRock Advisors, LLC serves as the investment advisor for the Trust.