GOV §21478: (a) A member who elects to receive the unmodified allowance or the optional settlement in Section 21474, or the optional settlement in Section 21475, 21475.

(a) A member who elects to receive the unmodified allowance or the optional settlement in Section 21474, or the optional settlement in Section 21475, 21475.5, 21476, 21476.5, or 21477, and who names his or her spouse as the option beneficiary, and whose spouse is also an eligible survivor for the benefits provided by Section 21624, 21626, 21627, 21628, 21629, or 21630, and if the total benefit to the surviving spouse is at least 50 percent of the member’s unmodified allowance, may concurrently and irrevocably elect to have his or her allowance paid as a “qualified joint and survivor annuity.” Notwithstanding any other provision of this part, upon the election, the survivor allowance shall be paid only to the member’s spouse and shall continue to be paid upon the remarriage of the spouse. Any cost due to this election shall be paid by the member through an actuarial reduction to his or her allowance. (b) For purposes of this section, a member’s retirement allowance shall be determined without regard to any limitation required pursuant to Section 415 of Title 26 of the United States Code but the amount payable to the spouse shall be subject to those limits as if it were the retirement allowance of the member. (c) This section shall apply to any member who retires on or after January 1, 2018.