Any overpayment, issued after the date of death to a member, retired member, or beneficiary, made to or on behalf of any member, retired member, or beneficiary, including, but not limited to, contributions, interest, retirement allowance, payments of any kind, or federal or state tax, shall be deducted from any subsequent payment or benefit that is payable by this system as a result of the death.
Ca. Gov. Code § 21499.1