Each member may retire the first of the month following the month during which such member shall reach normal retirement age with a normal annuity. Notwithstanding any other provisions to the contrary, a person receiving an annuity may waive monthly annuity payments or a cost-of-living adjustment (COLA) for periods of time, provided no waiver may be contrary to applicable federal law. A waiver shall be final as to any payment or COLA waived.
§ 104.080, RSMo