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