40 ILCS 5/22-901.2

Adjustment of retirement annuity under reversionary annuity option.

Any member or participant of a pension fund or retirement system covered by the provisions of this Code who elects a reversionary annuity option shall have his retirement annuity otherwise payable to him reduced by the actuarial equivalent of the amount required to provide the reversionary annuity according to the applicable ages of the member or participant and the reversionary annuity beneficiary.

The term "actuarial equivalent" shall mean an annuity or benefit of equal value to an annuity or benefit or accumulated contributions when computed according to the actuarial tables in effect for the pension fund or retirement system.