40 ILCS 5/8-143

Widow's annuity-Present employees and future entrants attaining age 65 in service.

The widow of a present employee who attains age 65 while in service after the effective date, or of a future entrant who attains age 65 while in service, is entitled, after the date of his death to an annuity fixed for the wife on the date he attains age 65.

The widow is entitled to annuity as follows:

If the employee's withdrawal occurs after age 65 and he enters upon annuity, or if the employee's death occurs in the service after his attainment of age 65, the annuity shall be that provided on a reversionary annuity basis from the total sums accumulated to his credit for widow's annuity and (if he was a present employee) widow's prior service annuity on the date he became age 65.