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