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