For the non-deductive basis:
[NOTE: When you get to the "Your 1099-R Entries" screen where you can add another 1099-R, use "continue" to keep going as there are additional interview questions after that screen in most cases. You can always return as shown above.]
You will be asked of you had and tracked non-deductible contributions - say yes. The enter the amount from the last filed 8606 form line 14 if it did not transfer. Then enter the total value of any Traditional, SEP and SIMPLE IRA accounts that existed on December 31, 2020.
That will produce a new 8606 form with the taxable amount calculated on lines 6-15 and the remaining carry-forward basis on line 14.
NOTE: If there is an * next to line 15 then 6-14 will be blank and the calculations will be on the "Taxable IRA Distributions worksheet instead.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
