(a) Upon application of an active and contributing member, any such member who has 10 or more years of membership service who becomes disabled may be retired on a disability retirement allowance by the Board of Control not less than 30 days nor more than 90 days next following the date of filing of such application; provided that the medical board, after a medical examination of such member, shall certify that such individual is totally and permanently mentally or physically incapacitated from regular and substantial gainful employment and that such member should be retired.

(b) Upon retirement for disability, the member shall receive a service retirement allowance if he or she has attained age 62; otherwise, he or she shall receive a disability retirement allowance which shall consist of an annuity, which shall be the actuarial equivalent of the member's accumulated contributions at the time of retirement, and a pension, which when added to the member's annuity shall be equal to three percent (3%) of the member's average final compensation multiplied by the member's number of years of membership service. Notwithstanding the foregoing, the disability retirement allowance shall not exceed eighty percent (80%) of the member's average final compensation.

(c) Once each year during the first five years following the retirement of a member on a disability retirement allowance and once every three-year period thereafter, the Board of Control may require any disability beneficiary who has not yet attained age 62 to undergo a medical examination, such examination to be made at the place of residence of such beneficiary or other place mutually agreed upon by a physician or physicians of or designated by the medical board. Should any disability beneficiary who has not yet attained age 62 refuse to submit to such medical examination, his or her retirement allowance may be discontinued until his or her withdrawal of such refusal, and should his or her refusal continue for one year, all his or her rights in and to his or her pension may be revoked by the Board of Control. Should the medical board report and certify to the Board of Control that a disability beneficiary has the capacity to engage in regular and substantial gainful employment, the Board of Control shall discontinue the beneficiary's retirement allowance until the beneficiary is otherwise eligible for service retirement.