The General Rule Method applies to form 1099-R.
Under the General Rule, you figure the taxable and tax-free parts of your annuity payments using life expectancy tables that the IRS issues. See IRS topic 411
Take a look at your 1099-R, box 2a. if it says, undetermined or something similar, leave the box blank in TurboTax. Then make sure that the "taxable amount is undetermined" box is checked. TurboTax will to generate the worksheet necessary to determine the amount of your annuity that will be taxable this year by applying the correct method. Usually, the simplified method is used to determine the taxable portion of the annuity, but sometimes you can recover after-tax contribution amounts using the general method.
Line 5 is the amount that represents your contribution amounts in the annuity.
You can't jump directly to general rule method within the software but the 1099-R is the area to look at to work on this issue.
@dvemerson
