|Apartment Investment and Management Company (Aimco) is a self-administered and self-managed real estate investment trust (REIT). AIMCO Properties, L.P. (the Aimco Operating Partnership), is a partnership formed to conduct the Company's business, which is focused on the ownership, management and redevelopment of apartment communities located in the United States. Aimco, through its wholly owned subsidiaries, AIMCO-GP, Inc. and AIMCO-LP Trust, owns an ownership interests in the Aimco Operating Partnership. Aimco conducts all of its business and owns all of its assets through the Aimco Operating Partnership. As of December 31, 2012 , the Company's portfolio of owned properties consisted of 265 properties with 67,977 apartment units. The Company's business is organized around two activities: Property Operations and Portfolio Management. During the year ended December 31, 2012, the Company acquired 84 properties in San Diego, 42 in Manhattan and 488 in Phoenix.