Hi,
Thank you for your answer. I did not have traditional IRA account nor converted any nonreducible contribution before 2019. I opened an account in Jan 2019 and made a nondeductible contribution of $6500 into the traditional IRA account for 2018 then converted to Roth IRA later. Then I made a nondeductible contribution of $7000 into the traditional IRA account for 2019 then converted to Roth IRA later. I thought I had to file form 8606 for 2018 and 2019 separately. So I entered 0 on line 2 in 2018 form 8606, and $6500 on line 2 in 2019 form 8606. But after the calculation, it seems I have to pay tax for the $500 difference of the limit between 2018 and 2019. So if the limit of 2018 had been $7000, I would not have to pay tax.
