a computerized method of administering a benefit plan providing systematic withdrawal payments during a liquidity period and annuity payments when the systematic withdrawal payments cease . the method includes steps of storing data relating to the plan , and performing a sequence of steps during the liquidity period to determine an account value , and initial and current benefit payments . the method further includes the steps of determining the account value to be annuitized at the end of the liquidity period , and determining and paying initial and current annuity payments during the annuity period . the method may be used when the benefit plan is a straight life annuity benefit plan , or a life annuity benefit plan having either a death benefit , a surrender benefit , or both .