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