1. If the medical board reports and certifies to the board of trustees that the disability beneficiary is engaged or is able to engage in a gainful occupation other than firefighter paying more than the difference between his or her retirement allowance and one and one-half times the then current rate of pay for the rank held by the member at the time of retirement, and if the board of trustees concurs in the report, then the amount of his or her retirement allowance shall be reduced to an amount which together with the amount earnable by him or her in such other occupation shall equal the amount of such current rate of pay. If his or her earning capacity is later changed, the amount of his or her retirement may be further modified. If any such disability beneficiary is found by such medical board to be able to engage in the occupation of firefighter, his or her retirement allowance shall not cease until he or she is restored to active service at the position and title held by such disability beneficiary at the time such disability occurred.

2. If a disability beneficiary is restored to active service, his or her retirement allowance shall cease and he or she shall again become a member. His or her creditable service at the time of his or her retirement shall be restored to full force and effect and in addition, upon his or her subsequent retirement, he or she shall be credited with all his or her additional service as a member, and if his or her then average final compensation is less than the average final compensation used in determining his or her disability benefits, the latter amount shall be used in determining benefits. In addition, an accident-disabled member restored to active service shall be credited with all the time he or she has served as a beneficiary.