dmertz
Level 15

After you file

If your 2017 tax return was filed showing the Roth conversion on Form 8606  Part II, your amendment must include the corrected Form 8606 to showing zeros in Part II in place of the original dollar amounts and Form 1040X to show the change in AGI.  TurboTax won't generate Form 8606 with all zeros in Part II, so you'll need to manually prepare the corrected form.