- The Arc (National Office)
- The Arc Baltimore
- The Arc Carroll County
- The Arc Central Chesapeake Region – Also serves Eastern Shore
- The Arc of Frederick County
- The Arc Howard County
- The Arc Montgomery County
- The Arc Northern Chesapeake Region – Harford & Cecil Counties
- The Arc Prince George’s County
- The Arc Southern Maryland – Calvert, Charles, & St. Mary’s Counties
- The Arc of Washington County