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