I won't be paying any additional amounts in 2021 because my tax information did not change. Unless I'm missing something? All my calculations are still fine on the main 1040 form. It's just that I entered the wrong information on Line 2 of Form 8606 for my prior basis (because I had not done the 2019 Form 8606...) But it didn't change my partial IRA deduction in 2021 and did not result in any changes in taxes since I didn't do any roth conversions or take any distributions. My main worry was the $50 penalty for late filing of 8606.
I guess I could try submitting just the Form 8606 alone for 2019? I know a lot of people do file the form separately. I just know that the IRS discourages filing a second amended return before the first one is processed.
