California Code, Education Code - EDC § 24208

(a) A member retired for service under this part may terminate the retirement allowance payable under this part and applicable to his or her credited service upon written request to the system effective upon a date designated by the member, subject to the following conditions:

(b) A member who files a request for termination of the retirement allowance may cancel or change the termination upon written request to the system. The request for cancellation or change must be on a form provided by the system and shall be received in the system's headquarters office no later than the last day of the month in which the request for termination to be canceled or changed is effective.

(c) A member whose retirement allowance is terminated pursuant to this section may apply for retirement pursuant to Section 24209 or Section 24209.3, in accordance with Section 24204.

(d) A member whose retirement allowance is terminated pursuant to this section may not file a preretirement election of an option pursuant to Section 24307 within one year of reinstatement that elects either a different option or a different beneficiary or set of beneficiaries, or both, than were in effect at the time the retirement allowance was terminated.

(e) A member whose retirement allowance is terminated pursuant to this section and retires pursuant to Section 24209 with a benefit effective date within one year of reinstatement shall elect the same option and beneficiary or beneficiaries that were in effect at the time the retirement allowance was terminated.