40 ILCS 5/2-122
An annuitant who re-enters service as a member shall become a participant on the date of re-entry and retirement annuity payments shall cease at that time. The participant shall resume contributions to the system on the date of re-entry at the rates then in effect and shall begin to accrue additional service credit. He or she shall be entitled to all rights and privileges in the system, including death and disability benefits, subject to the limitations herein provided, except refund of retirement annuity contributions.
Upon subsequent retirement, the participant shall be entitled to a retirement annuity consisting of: (1) the amount of retirement annuity previously granted and terminated by re-entry into service; and (2) the amount of additional retirement annuity earned during the additional service based on the provisions in effect at the date of such subsequent retirement. However, the total retirement annuity shall not exceed the maximum retirement annuity applicable at the date of the participant's last retirement. If the salary of the participant following the latest re-entry into service is higher than that in effect at the date of the previous retirement and the participant restores to the system all amounts previously received as retirement annuity payments, upon subsequent retirement, the retirement annuity shall be recalculated for all service credited under the system as though the participant had not previously retired.
The repayment of retirement annuity payments must be made by the participant in a single sum or by a withholding from salary within a period of 6 years from date of re-entry and in any event before subsequent retirement. If previous annuity payments have not been repaid to the system at the date of death of the participant, any remaining balance must be fully repaid to the system before any further annuity shall be payable.
Such member, if unmarried at date of his last retirement, shall also be entitled to a refund of widow's and widower's annuity contributions, without interest, covering the period from the date of re-entry into service to the date of last retirement.
Notwithstanding any other provision of this Article, if a person who first becomes a participant under this System on or after January 1, 2011 (the effective date of Public Act 96-889) is receiving a retirement annuity under this Article and becomes a member or participant under this Article or any other Article of this Code and is employed on a full-time basis, then the person's retirement annuity under this System shall be suspended during that employment. Upon termination of that employment, the person's retirement annuity shall resume and, if appropriate, be recalculated under the applicable provisions of this Article.
40 ILCS 5/2-122