(a) An employee who has withdrawn from service, has been on a leave of absence, is laid off or is out of pay status for any reason for more than 30 days, and who subsequently reenters service, shall not be entitled to ordinary or duty disability payments unless the employee (1) qualified for an ordinary or duty disability benefit before the absence from service, or (2) renders at least 6 months of service subsequent to the date of the last reentry.
     (b) An ordinary or duty disability benefit otherwise payable under this Article shall be suspended for the duration of any period during which the disabled employee receives salary or other compensation for personal services (but not including any worker’s compensation benefit) that exceeds 50% of the amount of the disability benefit.
     A person receiving an ordinary or duty disability benefit shall provide to the Board, upon request, a tax return, pay stub, or other documentation of earnings.