Backdoor Roth conversion and form 8606

[user17717116761]

Married filing jointly. After filing my 2024 taxes in Feb 2025, I made a traditional IRA contributions of $5k and a traditional IRA contribution of $5k for my wife for tax year 2024 (in early April). This contribution was non-deductible. We immediately did a backdoor Roth conversion of the full amounts. I mistakenly did not file a Form 8606. Now I am completing my 2025 taxes. In January 2026, I made a $7k contribution into each IRA and immediately completed backdoor Roth conversion. I was intending that to be a tax year 2025 contribution.

I'm having trouble getting the Form 8086 to be correct. When I first went through everything, it is documenting the two $5k contributions as for tax year 2025 instead of 2024. I want it to show $7k for each of us for tax year 2025. I will separately file a Form 8086 for tax year 2024 (and pay the $50 penalty, I assume). How do I get the Form 8086 for tax year 2025 to correctly indicate $7k in contributions for both me and my spouse? Is there a way to file the 2024 Form 8086 via TurboTax or do I have to do that on my own? (I filed using TurboTax both years.)

[baldietax · Accepted solution]

just to clarify when you make a backdated contribution to the prior tax year and convert to Roth, the Roth conversion part applies to the calendar year it is done, so if I'm following correctly from you've described you should have:

2024 - 5k contributions (in Q1 2025), no Roth conversion, 5k basis carryover

2025 - 7k contributions (in Q1 2026), 5k Roth conversion (maybe some earnings too?), 7k basis carryover

2026 - 7k Roth conversion (so far)

when preparing your 2025 taxes you wouldn't enter the 5k contributions, there should be a question whether you tracked basis and asks you for the basis from 2024 which will probably show $0 if you didn't have this in your 2024 filing & carryover - here you would enter 5k as the basis carried over from 2024 (confirm this lines up with your amended 2024 8606 Line 14), which will go to 2025 Form 8606 Line 2.

then enter your 2025 non-deductible contributions of 7k, 2025 Form 8606 Line 1+4 will show 7k and Line 3 will show 12k total etc.

you should have 1099-Rs for 5k (or more if you had some earnings between contribution and conversion?) so when you enter those and identify those at Roth conversions that will hit Line 8, Form 8606 will figure your tax and you should be left with 7k basis carryover to 2026.

in 2024 Turbotax I think you should be able to follow the amendment process (be sure to save copy of your original .tax2024 and PDF with all forms and worksheets from your initial filing - or help page below suggests doing a  "Save As"), and enter the 5k non-deductible contributions and it should generate the 2024 8606 you can print and mail, but you shouldn't need to file amendment if tax was not affected - see notes at end of the help for Backdoor Roth page below for case when you didn't file prior year 8606.

https://ttlc.intuit.com/turbotax-support/en-us/help-article/retirement-benefits/enter-backdoor-roth-...

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...

hope that helps get pointed in the right direction.

[AnnetteB6]

Instead of amending your 2024 return to include Form 8606, you should file the Form 8606 on its own to report the basis from the 2024 non-deductible contributions.  You will need to complete this form on your own rather than through TurboTax.

There is further information about this in the following TurboTax help article.  Scroll to the bottom of the document to find the section If your conversion contains contributions made in 2025 for 2024 for guidance.  There is also a link to a blank Form 8606 you can use.  

How do I enter a backdoor Roth IRA conversion?

@user17717116761 

[user17717116761]

Thank you! This was very helpful. Per your suggestion, I edited my 2024 tax info in turbotax online to document the March 2025 contribution for tax year 2024. It generated a Form 8606 for Tax Year 2024, which I will submit. (I did NOT submit amended returns, as nothing else changed.) Then I revised my 2025 tax information for just the $7k contribution(s) in Jan 2026. Now the Form 8606 for Tax Year 2025 in the 2025 return appears correct. Just one clarification - towards the end of the IRA section, turbotax asked me the balance of my Traditional IRA as of December 31, 2025 --> I put $0, since those funds had been converted to a Roth IRA. Is that the right way to document it? When I look at the 2025 Form 8606, both mine and my spouses look like:
Line 1  7000 (nondeductible contributions)

2  5001 (total basis)

3  12001 (1+2)

4  7000 (contributions in 2026 for tax year 2025)

5  5001 (4-3)

13 5000 (non-taxable distributions)

14 7001 (total basis for 2025 and earlier)

In Part II, the March 2025 conversion is documented:

Line 16 5000 (amount converted)

17 5000 (basis)

18 0 (Taxable amount)

This looks correct to me. Based on the info I provided, does it appear correct to you?