(a) Upon the withdrawal of a member from service prior to retirement for reasons other than death, the amount of the member's accumulated contributions with interest will be returnable to the member. In lieu of a return of contributions, any member who has completed five years of credited service, and at least two and one-half years of which have been as a contributing member, may allow his or her contributions to remain in the System and receive a deferred vested retirement allowance, commencing as early as the eligibility date for early retirement, which shall be equal to an early or a normal retirement allowance accrued to the member's date of termination of continuous service. The average final compensation used to calculate the normal retirement allowance under this section shall be increased or decreased annually by a cost of living adjustment equal to one-half of the percentage increase or decrease, calculated to the nearest one-tenth of a percent in the Consumer Price Index, as defined in section 5067 of this title, for the preceding fiscal year. The increase or decrease shall commence on the January 1 immediately following separation from service. The maximum annual adjustment of any retirement allowance resulting from any cost of living adjustment under this subsection shall be two percent for Group A members and three percent for Group B, Group C, or Group D members.

(b) Unless the designated dependent beneficiary elects to receive payment of a deceased member's accumulated contributions as provided under subsection (a) of this section, the retirement allowance payable to the dependent beneficiary of a deceased Group A, Group B, or Group C member under this section shall be equal to the retirement allowance that would have been payable had the member elected option 1 under section 5060 of this title and retired on the member's date of death; the retirement allowance payable to the spouse of a Group D member under this section shall be equal to 70 percent of the retirement allowance that would have been payable had the member retired on the member's date of death. In the case of a member who has not attained the normal retirement date as of his or her date of death, the retirement allowance shall be computed on the basis of a disability retirement allowance or an early retirement allowance, whichever provides the greater benefit to the dependent beneficiary. If the deceased member has no eligible designated dependent beneficiary, the member's accumulated contributions shall be payable to the member's designated beneficiaries. In the absence of a designated beneficiary, or in the event the designated beneficiary is deceased, the return of accumulated contributions with interest payable as a result of the death of the member prior to retirement shall be payable as follows: