Cal. Government Code § 31725.5

If the board finds, on medical advice, that a member in county employment, although incapacitated for the performance of his duties, is capable of performing other duties in the service of the county, the member shall not be entitled to a disability retirement allowance if any competent authority in accordance with any applicable civil service or merit system procedures offers and he accepts a transfer, reassignment, or other change to a position with duties within his capacity to perform with his disability. If this new position returns to the member compensation less than that of the position from which he was disabled, the board, in lieu of a disability retirement allowance, shall pay him the difference in such compensation until the compensation of the new position equals or exceeds the compensation (including later changes) of the former position, but such amount shall not exceed the amount to which he would otherwise be entitled as a disability retirement allowance. Such payments in lieu of disability retirement allowance shall be considered as a charge against county advance reserve for current service. If a new position cannot be arranged at the time of eligibility for disability retirement allowance, such disability retirement allowance to which the member is entitled under this article shall be paid until such time as a new position is available and accepted. If a disability retirement allowance is paid and the member later accepts such a new position, the period while on disability retirement shall not be considered as breaking the continuity of service and his rate of contributions shall be based on the same age as it was at the date of disability. The member’s accumulated contributions shall be the same as at the date his disability retirement began less the amount charged to his accumulated normal contributions. Nothing in this section shall be construed to require a member to accept reassignment or transfer in lieu of a disability retirement allowance. The provisions of this section become effective in any county only when the board of supervisors adopts an ordinance providing for their implementation by the board of retirement which may include application to persons retired for disability before such effective date. The provisions of this section shall only apply to members eligible to retire for nonservice-connected disability.