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