Amending in TurboTax is free if you used TurboTax to file your original return.
You
can do amend in TurboTax after your return has been
processed (generally 10-21 days) and you
have received your refund, if any. Here is a link to the instructions to Amend My Return in TurboTax.
TurboTax expects the Form 1040X, Amended U.S.
Individual Income Tax Return to be available for TurboTax customers to
amend an accepted return starting Thursday, March 7, 2019.
