A retirement community is a housing complex designed for older adults who are generally able to care for themselves; however, assistance from home care agencies is allowed in some communities, and activities and socialization opportunities are often provided. There is not single definition of a retirement community, but some of the characteristics typically are: the community must be age-restricted or age-qualified, residents must be partially or fully retired, and the community offers shared services or amenities.

Additionally, there are different types of retirement communities older adults can choose from including:

New types of retirement communities are being developed as the population ages including elder co-housing, which is defined later in this article. Retirement communities are often built in warm climates, and are common in Arizona, California, Florida and Texas but are increasingly being built in and around major cities throughout the United States. Youngtown, Arizona, established in 1954, was the first age-restricted community. Del Webb opened Sun City, Arizona, with the active adult concept, in 1960. In 2011, The Villages, Florida is the largest of these communities. While new retirement communities have developed in various areas of the United States, they are largely marketed to older adults who are financially secure. Lower income retirement communities are rare except for government subsidized housing, which neglects a large proportion of older adults who have fewer financial resources.