A naturally occurring retirement community (NORC; /nɔːrk/) is a community that has a large proportion of residents over 60 but was not specifically planned or designed to meet the needs of seniors living independently in their homes. NORCs may develop in three ways: * Aging in place: numerous persons moved into a community when they were younger * Emigration: older people remain in a community as younger residents move out * Immigration: numerous older people move into a community