40 ILCS 5/11-162
An employee who was not in the service of an employer or the retirement board of any annuity and benefit fund which is on an actuarial reserve basis on the effective date, who was in service prior to that date, and who re-enters service after that date and before age 65, shall not be credited for prior service annuity or widow's prior service annuity on account of service prior to the effective date. The period of service, prior to the effective date, shall, however, be included in computing service for age and service annuity and widow's annuity. Such employee shall be a future entrant for the purposes of this Article.
For any person employed by an employer prior to August 1, 1949, from whose salary deductions were made for the purposes of this Article for the first time after July 31, 1949, any service rendered prior to July 1, 1935, unless he was in service on the day before the effective date, shall not, regardless of any other provisions of this Article, be counted as service for the purposes of this Article.
Contributions by the employee to whom this section applies, and city contributions for age and service annuity and widow's annuity, shall be made as herein provided.
Any person employed by an employer, or retirement board, in which this Article was in force prior to August 1, 1949, who (1) was not a participant in this fund on August 1, 1949, (2) attained age 65 or more on or before July 1, 1950, and (3) fails to qualify as an employee by July 1, 1950, shall not be credited for any annuity purposes under this Article; nor shall any other person so employed, who attains age 65 before July 1, 1950, and before qualifying as an employee, be credited for any annuity purposes under this Article. Such persons shall not be considered employees.
40 ILCS 5/11-162