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