215 ILCS 125/4-10
Each Health Maintenance Organization shall provide a mechanism for the timely review by a physician holding the same class of license as the primary care physician, who is unaffiliated with the Health Maintenance Organization, jointly selected by the patient (or the patient's next of kin or legal representative if the patient is unable to act for himself), primary care physician and the Health Maintenance Organization in the event of a dispute between the primary care physician and the Health Maintenance Organization regarding the medical necessity of a covered service proposed by a primary care physician. In the event that the reviewing physician determines the covered service to be medically necessary, the Health Maintenance Organization shall provide the covered service. Future contractual or employment action by the Health Maintenance Organization regarding the primary care physician shall not be based solely on the physician's participation in this procedure.
215 ILCS 125/4-10