(a) Upon application for a disability benefit under this part, the participant may elect to receive the disabled benefit in the form of an annuity provided the sum of the employee account and employer account equals or exceeds three thousand five hundred dollars ($3,500). If the participant elects to receive the disability benefit as an annuity, the participant shall elect one of the following forms of payment:

1. (1) Participant only annuity. This is a single life annuity with a cash refund feature that is the actuarial equivalent of the amount that would be payable to the participant if the participant elected to receive the disability benefit in a lump-sum payment. Upon the death of the participant, an amount equal to the remaining balance of the participant’s contributions and interest shall be paid in a lump sum to the participant’s beneficiary.
2. (2) One hundred percent beneficiary annuity. This is a joint and survivor annuity that is the actuarial equivalent of the lump-sum payment modified to be payable over the combined lives of the participant and the participant’s annuity beneficiary. Upon the death of the participant, 100 percent of the monthly amount that was payable to the participant shall be paid monthly to the participant’s surviving annuity beneficiary.
3. (3) Seventy-five percent beneficiary annuity. This is a joint and survivor annuity that is the actuarial equivalent of the lump-sum payment modified to be payable over the combined lives of the participant and the participant’s annuity beneficiary. Pursuant to Section 401(a)(9) of the Internal Revenue Code, unless the annuity beneficiary is the participant’s spouse or former spouse who has been awarded a community property interest in the participant’s benefits under this part, the participant may not designate an annuity beneficiary under this annuity who is more than exactly 19 years younger than the participant. Upon the death of the participant, 75 percent of the monthly amount that was payable to the participant shall be paid monthly to the participant’s surviving annuity beneficiary.
4. (4) Fifty percent beneficiary annuity. This is a joint and survivor annuity that is the actuarial equivalent of the lump-sum payment modified to be payable over the combined lives of the participant and the participant’s annuity beneficiary. Upon the death of the participant, 50 percent of the monthly amount that was payable to the participant shall be paid monthly to the participant’s surviving annuity beneficiary.
5. (5) A period certain annuity. This form of payment is an annuity that is equal to the actuarial equivalent of the balance of credits in the participant’s Cash Balance Benefit account on the date the disability benefit becomes payable. The annuity shall be payable in whole year increments over a period of years specified by the participant, from a minimum of three years to a maximum of 10 years subject to life expectancy tables promulgated pursuant to Section 401(a)(9) of the Internal Revenue Code. If the participant’s death occurs prior to the end of the period certain, the remaining balance of payments shall be paid to the participant’s beneficiary pursuant to Section 27007.