215 ILCS 5/367d.1
After the effective date of this amendatory Act of 1992, no group policy of accident and health insurance that provides coverage for the treatment of alcoholism or other drug abuse or dependency on both an inpatient and outpatient basis may be issued, delivered or amended in this State if it excludes from coverage services provided by persons or entities licensed by the Department of Human Services to provide substance use disorder treatment , provided however that (a) the charges are otherwise eligible for reimbursement under the policy and (b) the services provided are medically necessary and within the scope of the licensure of the provider. This Section shall not apply to arrangements, agreements or policies authorized under the Health Care Reimbursement Reform Act of 1985; the Limited Health Service Organization Act; or the Health Maintenance Organization Act.
215 ILCS 5/367d.1