Cal. Gov. Code § 75006.6

The surviving spouse or eligible surviving child of a deceased judge who is receiving a monthly allowance from the Judges’ Retirement System, or a retired judge, if there is no spouse or eligible child, may designate a beneficiary to receive the pro rata allowance remaining payable in the month of his or her death. The designation may be made, changed or revoked at any time, provided that it is made in writing and filed with the Judges’ Retirement System.