The only way to be sure that you are getting the maximum amount is to do the 2019 amendment and also enter the claim on 2020. Then if the amendment is a better option you will file the amendment instead of claiming the amount on 2020. If these is not any appreciable difference, then it will be faster to use the 2020 return to claim the deduction. If you decide not to use the amendment, you can just cancel it in TurboTax. Don't complete the amendment until you are sure that you will want to file it. You will need to use a computer to amend 2019 with TurboTax.
Sign on to TurboTax on a computer, go to Tax home, and then reports and documents at bottom of screen. Select 2019 and follow the directions to amend. If you use the amendment, you will need to print and mail it. The cover page of the printout will have an address and a list of items to send with the amendment. Be sure to date and sign the amendment.
