For a code-T Form 1099-R reporting a distribution from an inherited Roth IRA, TurboTax requires that you determine the taxable amount yourself and enter the taxable amount in box 2a of TurboTax's 1099-R form. If the decedent's first Roth IRA contribution was for some year prior to 2017, the taxable amount of this code-T 2021 Form 1099-R is zero, otherwise the taxable amount is the amount of investment gains included in the distribution under the Roth IRA distribution ordering rules.
