Government Code § 21176

If a recipient of a disability retirement allowance reenters state service and is eligible for membership in this system, his or her allowance shall be canceled and he or she shall immediately become a member of this system. His or her individual account shall be credited with an amount that is the actuarial equivalent of his or her annuity at that time, as based on a disabled life, but not exceeding the amount of his or her accumulated contributions at the time of his or her retirement for disability. He or she shall receive credit for prior service in the same manner as though he or she had never been retired for disability.