I rolled over $17k of after tax 401k to traditional IRA in 2016 and then converted it to Roth IRA. Where do I enter that the $17k is after tax? 1099-R 2b is checked.

[scarter21]

Fidelity 401k 1099-R shows the withdrawal amount in box 2a as $0 taxable.  The Fidelity check went directly to traditional IRA at Vanguard.  I then converted the traditional IRA to Roth.  Vanguard 1099-R shows the full amount as taxable in box 2a with box 2b checked for taxable amount not determined.  I can't figure out where to enter that the amount shouldn't be taxed.  Thanks, Scott

[dmertz · Accepted solution]

After entering the Forms 1099-R:

1. Click the continue button on the Your 1099-R Entries page.
2. Answer "Yes, I made and tracked nondeductible contributions to my IRA."
3. Click the EasyGuide button on the Let's Find Your IRA Basis page.
4. Continue, then mark the box labeled "I transferred money from an employer's retirement plan to an IRA in 2016 or a previous year"  and continue.
5. Enter the amount of after-tax money rolled over from the 401(k) (the amount shown in box 5 of the Form 1099-R from the 401(k)).
6. Provide an explanation for this adjustment to your traditional IRA basis, i.e., that this was after-tax money rolled over from your 401(k).
7. Continue through the other pages and finally enter the December 31, 2016 total value of your traditional IRAs, if you had any traditional IRAs on that date.  (If you eventually decide to recharacterize any of this Roth conversion, you'll also enter that amount on this page.)