California Code, Government Code - GOV § 31783.5

(a) Whenever a person or estate entitled to payment of a member's accumulated contributions or any other benefit fails to claim the payment or cannot be located, the amount owed from the retirement fund shall be administered in accordance with subdivision (c).

(b) The board shall attempt to locate the claimant through means that the board in its sound discretion deems reasonable including, but not limited to, a registered or certified letter mailed to the last known address of the claimant.

(c) Notwithstanding any provision of law to the contrary, the amounts described in subdivision (a) shall be held for the claimant.  If the amounts are not claimed within five years after the last attempted contact with the claimant, the amounts shall be deposited in and become a part of the pension reserve fund.  The board may at any time after transfer of unclaimed amounts upon receipt of information satisfactory to it, authorize the return of amounts so held in reserve to the credit of the claimant.  Those amounts shall be paid only to claimants who have not yet attained the age for mandatory distribution under the Internal Revenue Code.