(a) A participant who retired and elected a beneficiary annuity pursuant to Section 26807.5 and designated his or her same-sex spouse or same-sex former spouse as annuity beneficiary may elect to change his or her annuity subject to all of the following:

1. (1) A participant who elected the 100 percent beneficiary annuity or the 50 percent beneficiary annuity may elect to change his or her beneficiary annuity to the 75 percent beneficiary annuity described in paragraph (3) of subdivision (a) of Section 26807.5, provided the participant’s same-sex spouse or same-sex former spouse is more than exactly 19 years younger than the participant.
2. (2) The annuity change made by the participant pursuant to this section is made on or after July 1, 2015, and on or before December 31, 2015.
3. (3) The participant married a same-sex spouse, the marriage is or was recognized by the United States government, any state government, or any foreign government, and his or her same-sex spouse or same-sex former spouse was designated as his or her annuity beneficiary prior to July 1, 2015.
4. (4) The same-sex spouse or same-sex former spouse is the current annuity beneficiary and remains the annuity beneficiary following the annuity change made pursuant to this section.
5. (5) The annuity beneficiary has not predeceased the participant as of the effective date of the annuity change made by the participant pursuant to this section.

(c) The annuity change made by the participant pursuant to subdivision (a) shall be on a properly executed form provided by the system subject to the following requirements:

1. (1) The form is signed and dated by the participant and the participant’s spouse, if applicable, on or after July 1, 2015, and on or before December 31, 2015.
2. (2) The date the form is received at the system’s headquarters office is within 30 calendar days after the date of the participant’s signature and within 30 calendar days after the date of the spouse’s signature, if applicable.

(e) A participant may cancel an annuity change made pursuant to subdivision (a) and elect to receive his or her benefit according to his or her prior annuity election provided the requirements of paragraphs (4) and (5) of subdivision (a) are still met. The cancellation shall become effective as of the date of the initial option change pursuant to subdivision (b) subject to the following requirements:

1. (1) The cancellation is made on a properly executed form provided by the system.
2. (2) The form includes the signatures of the participant and his or her spouse, if applicable, and the signatures are dated.
3. (3) The form is received at the system’s headquarters office within 30 calendar days after the date of the acknowledgment notice described in subdivision (d), regardless of whether the form is received after December 31, 2015.