(a) At least once each year during the first five years following the allowance of disability retirement annuity to any member, and at least once in every three-year period thereafter, until a member's attainment of age 65, the System shall require any disability beneficiary to undergo a medical examination to be made at the place of residence of the beneficiary, or any other place mutually agreed upon, by a physician or physicians engaged by the System. If an examination indicates that the beneficiary is no longer physically or mentally incapacitated for service in the position held by the member at the date of disability, payments by the system must be discontinued. The name of the member must then be placed on the appropriate list of candidates maintained for appointment to a position in the division for which he is found to be qualified at compensation at least equal to the rate he received at the time he last became a beneficiary.
(b) Any member receiving a duty disability retirement annuity or a non-duty disability annuity who resumes gainful employment, and his earnings together and disability retirement annuity, exceed the rate of compensation of the member at the date of retirement, the Board shall reduce the amount of disability annuity to an amount that, when added to the compensation being earned by the member, may not exceed the rate of compensation of the member at the date he last became a disability beneficiary.
(c) If disability beneficiary refuses to submit to a medical examination as herein provided, payments must be discontinued until a medical examination is conducted. If the medical examination is not conducted within one year, the System shall revoke all rights the member has to receive a disability retirement annuity.