I used Turbotax to file my tax return for both 2020 and 2021, but I neglected to file form 8606 for my nondeductible contribution in 2020. In 2021 I did a Roth-IRA conversion so now I need to pay tax for that after-tax contribution. I wonder: (1) Should I use Turbotax 2020 to file delinquent Forms 8606? Do I need to amend my tax return in 2020? (2) For the tax return 2021, how should I report this contribution? There is no form 8606 for me to report this contribution is after-tax.
A minor question, during my 2020 contribution, I contributed $6000 to Roth-IRA first and a few months later I realized I was not eligible to contribute to Roth-IRA. Therefore, I recharacterized the money to the traditional IRA, however, the $6000 had become $6100, so there was in fact $6100 going into the traditional IRA. Does this mean the extra $100 is an excessed contribution?
1) You can use TurboTax 2020 to generate Form 8606 or fill out Form 8606 and file it by itself.
2) This question is not clear. Did you make a contribution to Traditional IRA for 2021, other than the Roth conversion?
When you recharacterized the Roth IRA to Traditional IRA, it was as if you never contributed to the Roth IRA in 2020. The fact that you failed to file Form 8606 does not make the $6,000 after-tax (non-deductible) pre-tax. You can file 2020 Form 8606 by itself without amending your 2020 return because it won't change other information on your return. When you did the conversion from Traditional to Roth, only the $100 earnings are taxable. The $100 is not considered an excess contribution.
Assuming you did not contribute non-deductible Traditional IRA for 2021:
Enter the Conversion from a Traditional IRA to a Roth IRA
Inside TurboTax, search for 1099-r and select the Jump to link in the search results
On your Form 1040, Line 4a should be $6,000, Line 4b should be $100, which is the taxable earnings.
1) You can use TurboTax 2020 to generate Form 8606 or fill out Form 8606 and file it by itself.
2) This question is not clear. Did you make a contribution to Traditional IRA for 2021, other than the Roth conversion?
When you recharacterized the Roth IRA to Traditional IRA, it was as if you never contributed to the Roth IRA in 2020. The fact that you failed to file Form 8606 does not make the $6,000 after-tax (non-deductible) pre-tax. You can file 2020 Form 8606 by itself without amending your 2020 return because it won't change other information on your return. When you did the conversion from Traditional to Roth, only the $100 earnings are taxable. The $100 is not considered an excess contribution.
Assuming you did not contribute non-deductible Traditional IRA for 2021:
Enter the Conversion from a Traditional IRA to a Roth IRA
Inside TurboTax, search for 1099-r and select the Jump to link in the search results
On your Form 1040, Line 4a should be $6,000, Line 4b should be $100, which is the taxable earnings.
Thank you so much @FangxiaL
Yes, I also made $6000 contribution to the traditional IRA for 2021. So I made $12,100 Roth-IRA conversion in 2021 ($6000 from 2020 and $6000 from 2021 plus $100 taxable earnings).
I will follow your guidance and put $6000 as my IRA basis even though I don't have 2020 form 8606 at this point (going to file it soon).
One follow-up question, the address on my 2020 tax return is different from my current address, so for the 2020 form 8606 that I am going to file, what address should I use?