"Doing the update can be confusing but stick with it. Replace the amount in box 2a with the taxable amount (Gross Distribution minus the total QCD)."
Do not modify the amount in box 2a; doing so serves no purpose and risks the IRS flagging a reporting discrepancy. The amount in box 2a of a code 7 (or code 4) distribution this distribution from a traditional IRA (IRA/SEP/SIMPLE box marked) is required to be equal the amount in box 1, per the IRS instructions. TurboTax properly uses the box 1 amount when determining that taxable amount of a traditional IRA distribution and, when the amount transferred to charity is entered, automatically excludes the QCD amount from taxable income.
