305 ILCS 5/5-4.1
The Department may by rule provide that recipients under any Article of this Code shall pay a federally approved fee as a co-payment for services. No co-payment requirement can exist for renal dialysis, radiation therapy, cancer chemotherapy, or insulin, and other products necessary on a recurring basis, the absence of which would be life threatening, or where co-payment expenditures for required services and/or medications for chronic diseases that the Illinois Department shall by rule designate shall cause an extensive financial burden on the recipient, and provided no co-payment shall exist for emergency room encounters which are for medical emergencies. The Department shall seek approval of a State plan amendment that allows pharmacies to refuse to dispense drugs in circumstances where the recipient does not pay the required co-payment. Co-payments may not exceed $10 for emergency room use for a non-emergency situation as defined by the Department by rule and subject to federal approval.
305 ILCS 5/5-4.1