California Code, Education Code - EDC § 24801

(a) Any other provisions of law to the contrary notwithstanding, whenever any retirement benefits under a district retirement system payable solely by reason of death of the retired member to his or her estate, heir or beneficiary have been unclaimed for a period of four years from the date of notification, by the district retirement system, by means of United States mail, to the estate, heir or beneficiary, such funds shall revert to and become a part of the contributions of the district and shall be applied to reduce the cost to the taxpayers of the district maintaining the retirement system.

(b) The district retirement system may at any time after reversion of these benefits to the district and upon receipt of proper information satisfactory to it, return from district contributions, an amount equal to that which had, on account of the deceased member, reverted to the district.