A computer-implemented method for administering an annuity product includes storing by a processor in memory an amount of an initial funding payment, an interest rate formula and a term for an accumulation annuity, and storing terms including a deferral term for a guaranteed income annuity. If the processor determines that the current time is during the term, the processor calculates an amount of interest earned on the fixed rate annuity and storing in memory a credit of the calculated interest amount to a guaranteed income annuity. After the accumulation period, the processor provides an output signal indicative of instructions to provide a notice of expiration. After the deferral period, the processor calculates an income annuity payment amount from the guaranteed income annuity; and provides an output signal indicative of instructions for a payment to be made to an annuitant based on the income annuity payment amount.