The distribution shall become payable on (i) July 1, 1987, (ii) December 1 of the calendar year immediately following the calendar year in which the member or annuitant died, or (iii) December 1 of the calendar year in which the deceased member or annuitant would have attained age 72 , whichever occurs latest, and shall remain payable until the first of the following to occur: (1) the person becomes eligible to receive a monthly survivor benefit under this Article; (2) the day following the date on which the member ceases to be eligible to receive a monthly survivor benefit upon attainment of age 50, due to remarriage or death; or (3) the day on which such distribution ceases to be required by federal law.
The amount of the distribution shall be fixed at the time the distribution first becomes payable, and shall be calculated in the same manner as the monthly survivor benefit under Sections 16-141, 16-142, 16-142.1 and 16-142.2, but excluding any automatic annual increases, supplemental increases, or one-time increases that may be provided by law for monthly survivor benefits.
40 ILCS 5/16-142.3