Illinois Statutes Chapter 40. Pensions § 5/16-154. Deductions from salary

(a) Required contributions. The governing body of each school district and of each employing unit coming under this System, and the State Comptroller or other State officer certifying payroll vouchers, including payments of salary or wages to teachers, shall pick up or retain on every pay day the contributions required under Section 16-152 of each member. Each governing body or officer shall furnish a statement to each member showing the amount picked up or retained from his or her salary.

(b) Optional contributions. For the purposes of this Section and Section 16-152.1, “optional contributions” means contributions that a member elects to make in order to establish optional service credit or to reinstate creditable service that was terminated upon payment of a refund.

The governing body of each school district and of each employing unit coming under this System and the State Comptroller or other State officer certifying payroll vouchers shall take the steps necessary to comply with the requirements of Section 414(h)(2) of the Internal Revenue Code of 1986, as amended,  1 to permit the pickup of optional contributions on a tax-deferred basis. Beginning July 1, 1998, a school district or other employing unit shall not withhold optional contributions from the salary of any member on an after-tax basis.