Apartment Investment and Management Company (AIMCO) is a real estate investment trust (REIT) that engages in the acquisition, ownership, management, and redevelopment of apartment properties. The company rents and leases its apartment units to a diverse base of residents. It also provides management services to third-party owners. As of June 30, 2010, AIMCO owned or managed a real estate portfolio of 817 apartment properties containing approximately 129,000 apartment units located in 43 states, the District of Columbia, and Puerto Rico. As a REIT, the company would not be subject to federal income tax, if it distributes at least 90% of its taxable income to its shareholders. AIMCO was founded in 1975 and is headquartered in Denver, Colorado.