Cal. Gov. Code § 21464
Notwithstanding any provision of this part, a retired member who chose no optional settlement or optional settlement one at retirement and who marries after retirement may elect to have the actuarial equivalent, as of the date of the election, of the allowance payable for the remainder of the member's lifetime applied to a lesser allowance during the member's remaining lifetime under one of the optional settlements specified in this article and name the member's spouse as beneficiary.
The election provided by this section is irrevocable and shall be made within 12 months following a member's marriage if the spouse is named as beneficiary. The election shall become effective on the date specified on the election, provided that this date is not earlier than the day following receipt of the election in this system pursuant to this section.
A member who married prior to or after January 1, 1988, who fails to elect within 12 months, shall retain the right to make an election under this section. However, the election shall become effective no earlier than 12 months after the date it is filed with the board, provided that neither the member nor the designated beneficiary die prior to the effective date of the election.
This section shall not be construed to mean that designation of a new beneficiary causes the selection of an optional settlement. An optional settlement shall be selected by a member in a writing filed by the member with the board.
This section shall apply to any member who retires on or before December 31, 2017.
Ca. Gov. Code § 21464