(a) An annuity payable under the Defined Benefit Supplement Program shall be determined as a value actuarially equivalent to the balance of credits in the member’s Defined Benefit Supplement Program account on the member’s retirement date and after any lump-sum payment. If a single life annuity is elected, the annuity shall be calculated using the age of the member on the member’s retirement date. A member may elect a single life annuity only if the member did not elect to receive a modified allowance pursuant to Section 24300 or 24300.1. If a joint and survivor annuity is elected, the annuity shall be calculated using the age of the member and the age of the member’s beneficiary on the member’s retirement date. A member may elect a joint and survivor annuity only if the member elected to receive a modified allowance pursuant to Section 24300 or 24300.1.
(b) The beneficiary designation made pursuant to Section 24307 is not applicable to benefits payable under this chapter.