A computer-readable storage medium bearing instructions for administering an annuity account of an annuitant, the annuity account having an account value based on funds allocated to at least one investment, the annuity account having a term including a plurality of periods of time, an income base, a minimum periodic increase of the income base, and a maximum periodic withdrawal amount in one period that may be withdrawn without affecting an income base, the instructions, when executed by a computer, cause the computer to perform the steps of:
- setting an initial value for the income base;
- setting an initial value for the minimum periodic increase of the income base;
- setting an initial value for the maximum periodic withdrawal amount;
- periodically determining the value of the annuity based upon the account value of the annuity at the end of the period;
- periodically determining the income base based upon (i) the periodic value of the annuity, (ii) the income base with the minimum periodic increase of the income base applied, or (iii) a predetermined combination of the periodic value and the income base with the minimum periodic increase of the income base applied;
- and
- periodically determining the maximum periodic withdrawal amount based upon the income base.