Where is TurboTax getting my IRA conversion basis?

[Matt18]

I'm doing an IRA to Roth conversion and somehow TurboTax already has a basis (deductible amounts) for my IRA.  I'm not sure where it's coming from.   I did an electronic import of my Vanguard 1099-R to TurboTax. It doesn't have any IRA basis information on the 1099-R form, but is Vanguard providing this to TurboTax separately (electronically but not showing in the 1099-R form)?

TurboTax is generating an IRA Information Worksheet for line 2 of 8606. There are several amounts on here that I never entered this year.  Line 12 has a basis and line 14 is showing rollover amounts. The rollover amounts seem to be the amounts of 401k rollovers I did.  But I never entered these in. 

I've been using TurboTax for the last 5 years but my basis information goes back the past 20 years.

I'm trying to figure out if the IRA basis that TurboTax is presenting is correct.  If it is getting it from Vanguard, then I assume it is. Does the electronic import provide more information than is on the 1099-R?  if not, how is Vanguard figuring out my basis?

[DanaB27 · Accepted solution]

If you used TurboTax last year and had a basis (nondeductible traditional IRA contributions) on your 2021 Form 8606 line 14 then this will automatically be carried over to your 2022 tax return. If this isn't correct then you might have to review your 2021 tax return.

Line 12 on the IRA Information worksheet is the amount from line 14 of your 2021 Form 8606 and carried over from the previous year. Line 14 is also carried over from previous years when you entered Form 1099-R for your 401k rollover and answered the follow-up questions.

@Matt18 

[Matt18]

Thanks @DanaB27 .  That makes sense. But I still don't know how TT got some of the information since I've only been using TT for 5 years and the rollover info was from many years before.  Is any of the IRA basis information passed from Vanguard to TT during the 1099 import?

[DanaB27]

No, this basis information isn't imported with the Form 1099-R. It should come from your prior year's tax return import. I assume you entered this information in prior years into TurboTax and TurboTax imported that information when you started your 2022 return. But it is always a good idea to check this information with your own records to make sure information is correctly transferred from year to year.

@Matt18