California Code, Education Code - EDC § 23802

(a) Upon receipt of proof of death of a member who has no preretirement option in effect, and who either does not meet the eligibility requirements set forth in Section 23804, or meets the eligibility requirements set forth in Section 23804 but has no eligible survivors for a family allowance as specified in Section 23805 or 23806, there shall be paid to the beneficiary both of the following:

(b) Accumulated contributions include credited interest through the date of payment.

(c) A beneficiary may waive the right to the lump-sum payment pursuant to this section in accordance with the requirements established by the system.  The waiver shall be submitted on a properly executed form prescribed by the system.  The filing of a waiver by a beneficiary constitutes a complete and immediate discharge of all obligations of the board, the system, or the plan to, or on behalf of, the beneficiary.