Please schedule a Local Office: In-Person Appointment or call us at 1-855-457-2489. The State of Illinois Deferred Compensation Plan is a supplemental retirement program for State employees.Your 457(b) deferred compensation allows public employees like you to put aside money from each paycheck toward retirement. Find your employer's plan. Download any State of Illinois Deferred Compensation Plan form now using Acrobat Reader. These forms allow data to be typed into the form and saved.