AvalonBay Communities, Inc. is a real estate investment trust. They focus on the ownership and operation of upscale apartment communities in high barrier-to-entry markets of the United States. These markets include Northern and Southern California and selected states in the Mid-Atlantic, Northeast, Midwest and Pacific Northwest regions of the country. AvalonBay is the surviving corporation from the merger of Avalon Properties, Inc. with and into Bay Apartment Communities, Inc.