Founded in 1977, the InterAgency Council of Developmental Disabilities Agencies is a not-for-profit membership corporation of voluntary, non-profit providers of services to the intellectually and developmentally disabled in the New York City metropolitan area. Representing some 150 corporations, or three-fourths of the voluntary providers in the metropolitan area, IAC members provide services in the areas of clinical and diagnostic service; early intervention, preschool and school-age education; residential service; vocational rehabilitation; adult day services; transportation and family support services. The main purposes of the InterAgency Council are to plan, coordinate and integrate the voluntary-operated services to this population in the metropolitan area, and promote both private and public policies and programs in furtherance of the welfare of this population.