| The Arc of Solomon Valley | Promotes and protects the human rights of people with intellectual and developmental disabilities and actively supports their full inclusion and participation in the community throughout their lifetimes. |
| The Arc of Somerset County | Provides a lifetime of comprehensive services, advocacy and support to individuals with intellectual and developmental disabilities and their families to promote growth, achievement and ongoing involvement in the community. |
| The Arc of South Florida | Protecting and providing for the needs of the people with intellectual and developmental disabilities. |
| The Arc of South Norfolk County | Committed to providing exceptional supports to people with developmental disabilities, including autism, through collaboration, advocacy and empowerment. |
| The Arc of Southeast Iowa | Committed to being a leader in offering information, services and advocacy to individuals with developmental disabilities, their families and community; to promote informed choices and the realization of their goals relating to where and how they live, learn, work and play. |
| The Arc of Southeast Mississippi | Promotes and protects the human rights of people with intellectual and developmental disabilities and actively supports their full inclusion and participation in the community throughout their lifetimes. |
| The Arc of Southern Maryland – Calvert County Office | Creating opportunities for independence and personal success for people with different abilities in inclusive communities. |
| The Arc of Southern Maryland – Charles County Office | Creating opportunities for independence and personal success for people with different abilities in inclusive communities. |
| The Arc of Southern Maryland – St. Mary’s Office | Creating opportunities for independence and personal success for people with different abilities in inclusive communities. |
| The Arc of Southern Virginia |