| 1199SEIU in Greenbelt, MD | AMERIGROUP in Greenbelt, MD |
| APS Healthcare in Greenbelt, MD | Aetna in Greenbelt, MD |
| Alliance in Greenbelt, MD | AmeriHealth in Greenbelt, MD |
| American Behavioral in Greenbelt, MD | Beech Street in Greenbelt, MD |
| Behavioral Health Systems in Greenbelt, MD | BlueCross and/or BlueShield in Greenbelt, MD |
| CCN in Greenbelt, MD | CHIPA/College Health in Greenbelt, MD |
| Cascade Health in Greenbelt, MD | Ceridian in Greenbelt, MD |
| ChoiceCare in Greenbelt, MD | Cigna in Greenbelt, MD |
| ComPsych in Greenbelt, MD | Corphealth in Greenbelt, MD |
| Coventry in Greenbelt, MD | First Choice Health in Greenbelt, MD |
| First Health in Greenbelt, MD | GHI/Group Health Incorporated in Greenbelt, MD |
| Great-West in Greenbelt, MD | Guardian in Greenbelt, MD |
| HFN in Greenbelt, MD | HIP/Health Plan of New York in Greenbelt, MD |
| Harvard Pilgrim Health Care in Greenbelt, MD | Health Net in Greenbelt, MD |
| Holman Group in Greenbelt, MD | Horizon Healthcare in Greenbelt, MD |
| Humana in Greenbelt, MD | Integrated Health Plan in Greenbelt, MD |
| Interplan in Greenbelt, MD | Kaiser in Greenbelt, MD |
| LifeWise in Greenbelt, MD | MAMSI in Greenbelt, MD |
| MHN/Managed Health Network in Greenbelt, MD | Magellan Behavioral Health in Greenbelt, MD |
| MagnaCare in Greenbelt, MD | Medica in Greenbelt, MD |
| Medicaid in Greenbelt, MD | Medical Mutual in Greenbelt, MD |
| Medicare in Greenbelt, MD | Multiplan in Greenbelt, MD |
| NCPPO in Greenbelt, MD | ODS in Greenbelt, MD |
| Oxford in Greenbelt, MD | PHCS/Private Health Care Systems in Greenbelt, MD |
| PPOM in Greenbelt, MD | PacifiCare in Greenbelt, MD |
| PacificSource in Greenbelt, MD | PreferredOne in Greenbelt, MD |
| Providence in Greenbelt, MD | Sloans Lake in Greenbelt, MD |
| TRICARE in Greenbelt, MD | TriWest0127 in Greenbelt, MD |
| Tufts in Greenbelt, MD | UniCare in Greenbelt, MD |
| Uniform in Greenbelt, MD | United in Greenbelt, MD |
| VMC in Greenbelt, MD | ValueOptions in Greenbelt, MD |
| WellPoint in Greenbelt, MD |