California Code, Government Code - GOV § 21197

(a) His or her application to the board for reinstatement.

(b) The determination of the board, based upon medical examination, that he or she is not incapacitated for the duties to be assigned to him or her.

(c) The determination of the board that the employer from whose employment the person was retired for industrial disability has been furnished a notice of intent to reinstate that person, that contains information that he or she may be entitled to resume an industrial disability retirement allowance using the salaries earnable under the miscellaneous member position upon termination of the miscellaneous member employment.