The Arc is a membership organization made up of people with intellectual and developmental disabilities, their families, friends, interested citizens, and professionals in the disability field. 

Together we form state and local chapters of The Arc, the largest volunteer-based organization in the United States devoted solely to working on behalf of its constituency. The Arc also advocates for people without the label of intellectual/developmental disability but who, at times, will need similar supports and services in order to be productive and independent as possible.