40 ILCS 5/11-221
Periods of service for the aforesaid employee shall include service in the armed forces of the United States if he left the employment of an employer to enter the armed forces and returned to the employ of the employer within 90 days after his discharge from such armed forces, and if such employer has not made such payment on his behalf. Those periods for which he has received and retains credit in some other annuity or pension fund in operation in such city for the benefit of employees of an employer shall not be included. Upon making such payments such employee shall be credited with concurrent city contributions at the rates in effect for contributors during the period of time such service was rendered. Such payments and concurrent city contributions shall be made with interest at the effective rate and shall together with all other amounts contributed by or for such employee for all annuity purposes, be considered in computing the annuity or annuities to which such employee or his widow shall have a right. Any such period of service for which payment is made by such employee shall be counted as a period of service for annuity purposes under this Article.
Until the effective date of this amendatory Act of 1991, in order to be credited for a minimum annuity, all such payments by a contributor must be made in full while such contributor is still in the service; if payment is not made in full while such contributor is in service, any payments made shall be refunded to him when he withdraws from the service or to his widow in the event of his death or if no widow in accordance with the other refund provisions of this Article. Such employee may elect to have such partial payments together with the concurrent city contributions and interest, credited and applied for age and service and widow's annuity, for himself and his wife, on the assumption that the payments made shall apply to his earliest service. In the event of his death while in the service, his widow may elect to have such payments and related city contributions and interest, credited for widow's annuity, to the extent that they do not increase her annuity above that which she could have received if such amounts were included, and an annuity were fixed for her on the assumption that her deceased husband had continued in service at the rate of his final salary until he became 65 years of age.
Beginning on the effective date of this amendatory Act of 1991, an employee who is still in service may elect to establish credit under this Section for only a fraction of the service that he or she is eligible to establish under this Section. In such cases, the credit established shall be deemed to relate to the earliest service for which credit may be established. In no event shall such credit be granted until the corresponding employee contributions have been paid.
Beginning on the effective date of this amendatory Act of 1997, any employee who is in service, or within 90 days after withdrawing from service, or who is an active contributor to a participating system as defined in the Retirement Systems Reciprocal Act, may make payments and establish credit under this Section.
40 ILCS 5/11-221