– Aetna Health Inc. (Aetna Health) – (HMO) – Aetna Life Insurance Co. (Aetna Life) – (HMO) – Celtic Insurance Company (Celtic) – (HMO) – CIGNA HealthCare of Illinois, Inc. (Cigna) – (HMO) – Health Care Service Corporation, a Mutual Legal Reserve Company (HCSC, aka Blue Cross Blue Shield of IL) – (HMO and PPO) – Health Alliance Medical Plans, Inc. (HAMP) – (HMO and POS) – MercyCare HMO, Inc. – (HMO) – Molina Healthcare of Illinois, Inc. (HMO) – Oscar Health Plan, Inc. (HMO) – Quartz Health Benefit Plans Corporation (Quartz) – (HMO) – Medica Central Health Plan (formerly known as SSM Health Plan) – (HMO) - 伊利诺伊州联合医疗公司(HMO)