40 ILCS 5/5-199
Amounts contributed by the city for age and service annuity, widow's annuity and supplemental annuity, (except those contributed instead of deductions from salary of any policeman receiving duty disability benefit); also amounts transferred to this reserve from the investment and interest reserve shall be credited to this reserve.
At least once each year, and always before any transfer is made from this reserve to any other reserve, the sums credited shall be improved by the proper interest accretions.
When the amount of annuity for a policeman or to the widow is fixed, and when supplemental annuity for a widow first becomes payable, the total amount in this reserve for the purpose of such annuity and required therefor shall be charged thereto and credited to the annuity payment reserve.
If there is to the credit of any policeman who withdraws an amount in excess of that required to provide age and service annuity, or in excess of that required to provide widow's annuity for his wife (either or both), such amount shall be retained in this reserve and improved by interest until the policeman withdraws or dies, whichever event occurs first; provided, however, that in the case of a policeman who attains age 63 prior to January 1, 1988 while still in service, no interest shall be credited between the date the policeman attains age 63 and January 1, 1988. Any such accumulated amount shall then be applied as provided in this Article.
40 ILCS 5/5-199