"Basically, a NORC is a place (a building, a development, a neighborhood) with a sizeable senior community that wasn't purpose-built as a senior community. What counts as a "sizeable elderly population" varies from place to place (and from one level of government to the next), but NORCs are important because once a community meets the respective criteria, it becomes eligible for local, state, and federal funds retroactively to provide that community with the support services elderly populations typically need. These include (but are not limited to): case management and social work services; health care management and prevention programs; education, socialization, and recreational activities; and volunteer opportunities for program participants and the community.
As it happens, there are 27 NORCS in New York City, located in 4 boroughs."
Interboro, an urban design, planning and architecture firm, examines the cities NORCs and offers a new book highlighting their role in housing the city's aging population.