Cal. Education Code § 23859

(a) Upon termination of a survivor benefit allowance pursuant to this chapter, if the total allowance paid or payable is less than the amount of the member’s accumulated retirement contributions at the time of death, the remaining balance of accumulated retirement contributions shall be paid to the estate of the spouse. (b) If there is no spouse, and if there is a designated beneficiary pursuant to Section 23300, then upon termination of the survivor benefit allowance payable to all eligible dependent children pursuant to Section 23852, if the total allowance paid or payable is less than the amount of the member’s accumulated retirement contributions at the time of death, the remaining balance of the accumulated retirement contributions shall be paid to the member’s designated beneficiary pursuant to Section 23300. (c) Payments provided under this section shall include credited interest on the unpaid balance calculated from the date the last survivor benefit allowance payment was made or from the date of death of the member, if no survivor benefit allowance payments were made, to the date the balance is paid.