Cal. Gov. Code § 31706
Any member who has left county service and has elected to leave accumulated contributions in the retirement fund, or who is deemed to have elected a deferred retirement pursuant to subdivision (b) of Section 31700, and who has attained 70 years of age but has not yet applied for a deferred retirement allowance, and who is not a reciprocal member of a retirement system established pursuant to this chapter or the Public Employees' Retirement Law, shall be notified in writing by the board that the member is eligible to apply for, and shall begin receiving, either a deferred retirement allowance by the required beginning date specified in Section 401(a)(9) of Title 26 of the United States Code or a one-time distribution of all accumulated contributions and interest. The notification shall be made at the time the deferred member attains 70 years of age and shall be sent by certified mail to the member's last known address, or to the member's last known employer, as shown by the records of the retirement system. If the member can be located but does not make proper application for a deferred retirement allowance with retirement to be effective by the required beginning date specified in Section 401(a)(9) of Title 26 of the United States Code, the retirement system shall commence paying either an unmodified allowance to the member, if the member was eligible to begin receiving a deferred retirement allowance under the provisions of Section 31485.22, or a one-time distribution of all accumulated contributions and interest if the member is otherwise ineligible for a deferred retirement allowance. If the member cannot be located by the required beginning date specified in Section 401(a)(9) of Title 26 of the United States Code, all of the member's accumulated contributions and interest thereon shall be deposited in, and become a part of, the current pension reserve fund of the retirement system. The board may at any time after transfer of proceeds to the reserve fund upon receipt of proper information satisfactory to it, redeposit the proceeds to the credit of the claimant, to be administered in the manner provided under this law. This section shall not apply to a member while the member is actively employed past mandatory retirement age in a retirement system established under the provisions of this chapter or the Public Employees' Retirement Law.
Ca. Gov. Code § 31706