Cal. Gov. Code § 31452.5

The board may comply with and give effect to a revocable written authorization signed by a retired member or beneficiary of a retired member entitled to a retirement allowance or benefit under this chapter, authorizing the treasurer or other entity authorized by the board to deduct a specified amount from the retirement allowance or benefit payable to any retired member or beneficiary of a retired member for the purpose of paying premiums on any policy or certificate of group life insurance or group disability insurance issued by an admitted insurer, for any prepaid group medical or hospital service plan, or both, for any vision care program or dental plan, approved by the board, for the benefit of the retired member or his or her dependents, for the payment of premiums on national service life insurance or United States government converted insurance, for the purchase of shares in or the payment of money to any regularly chartered credit union, for charitable organizations or federally chartered veterans’ organizations as approved by both the board of retirement and the board of supervisors, or for the purchase of United States Savings Bonds, or for the payment of personal income taxes to the government of the United States or of the State of California, and each month shall draw his or her order in favor of the insurer, institution, credit union, or government named in the written authorization for an amount equal to the deductions so authorized and made during the month. The board may charge a reasonable fee for the making of the deductions and payments.