40 ILCS 5/14-125
The nonoccupational disability benefit shall be 50% of the member's final average compensation at the time disability occurred. In the case of a member whose benefit was resumed due to the same disability, the amount of the benefit shall be the same as that last paid before resumption of State employment. In the event that a temporary disability benefit has been received, the nonoccupational disability benefit shall be subject to adjustment by the Board under Section 14-123.1.
If a covered employee is eligible for a disability benefit before attaining the Social Security full retirement age or a retirement benefit on or after attaining the Social Security full retirement age under the federal Social Security Act, the amount of the member's nonoccupational disability benefit shall be reduced by the amount of primary benefit the member would be eligible to receive under such Act, whether or not entitlement thereto came about as the result of service as a covered employee under this Article. The Board may make such reduction if it appears that the employee may be so eligible pending determination of eligibility and make an appropriate adjustment if necessary after such determination. The amount of any nonoccupational disability benefit payable under this Article shall not be reduced by reason of any increase under the federal Social Security Act which occurs after the offset required by this Section is first applied to that benefit.
As used in this Section , "Social Security full retirement age" means the age at which an individual is eligible to receive full Social Security retirement benefits.
40 ILCS 5/14-125