820 ILCS 63/10
All covered employers shall provide a pre-tax commuter benefit to covered employees. The pre-tax commuter benefit shall allow employees to use pre-tax dollars for the purchase of a transit pass, via payroll deduction, such that the costs for such purchases may be excluded from the employee's taxable wages and compensation up to the maximum amount permitted by federal tax law, consistent with 26 U.S.C. 132 (f) and the rules and regulations promulgated thereunder. A covered employer may comply with this Section by participating in a program offered by the Chicago Transit Authority or the Regional Transportation Authority.
This benefit must be offered to all employees starting on the employees' first full pay period after 120 days of employment. All transit agencies shall market the existence of this program and this Act to their riders in order to inform affected employees and their employers.
820 ILCS 63/10