@fanfare, I understand that the IRS lumps all of one's IRAs together when it comes to satisfying RMDs. However, on p.14 of the 2020 version of Publication 590-B, is the following statement: "If your IRA includes nondeductible contributions, the distribution is first considered to be paid out of otherwise taxable income." [Emphasis added] My IRA distributions in 2020 were all "otherwise taxable income," namely, funds untaxed before they were deposited plus interest earned thereon. Therefore, even if I had made a withdrawal from the IRA with a basis, that basis should not have been effected.
I have now completed Form 8606 by hand, following the instructions carefully. The amount I compute on Line 14 is $5,585, which is unchanged from the 2019 basis, not the reduced amount computed by TurboTax Deluxe Desktop 2020.
