65 ILCS 5/10-1-47
An employee who has been on disability leave or military leave granted by the commission and who wishes to return to active duty in his certified position shall be credited with seniority for the period of such leave and, if otherwise qualified, shall be reinstated to his certified position at the rank or grade held at the start of the leave, not more than 60 days after his written request for reinstatement is filed with the commission. Such request shall be filed not more than 30 days after termination of the disability or military or naval service.
Upon the chief of the police department's receipt of a certification under Section 3-116 of the Illinois Pension Code that a police officer is no longer disabled and is able to resume the duties of his or her position, the police officer shall report to the chief of the police department. The chief of the police department shall thereupon order immediate reinstatement into active service, and the municipality shall immediately return the police officer to its payroll, in the same rank or grade held at the date he or she was placed on a disability pension under Article 3 of the Illinois Pension Code.
65 ILCS 5/10-1-47