Apartment Investment and Management Company (AIMCO) aims to be the top apartment landlord in the US. As one of the nation's largest apartment owner/managers (on par with Equity Residential) with some 200 apartment communities spanning 50,000-plus units, the self-managed real estate investment trust (REIT) specializes in buying, managing, and redeveloping multi-family residential homes in top rental markets in the US including Los Angeles, Washington, DC, Philadelphia, and Boston. Operating arm AIMCO Properties holds and manages most of AIMCO's assets, which include suburban communities, high-rises, and subsidized affordable housing.