Ill. Admin. Code tit. 56, § 252.35 – Initiation of Hearing

a) The Department shall serve its decision on the parties via certified U.S. mail, postage prepaid, return receipt requested, addressed to the last known addresses of the parties. A party may request a hearing within ten days after the date of service via certified mail or personal delivery to the Department.
b) Hearings shall be conducted pursuant to the provisions of Article 10 of the Illinois Administrative Procedure Act [5 ILCS 100/Art. 10] and the Department's Rules of Procedure in Administrative Hearings (56 Ill. Adm. Code 120).