Yes, you can use TurboTax to prepare your amendment, even if you did not file using the software.
Instructions on how to prepare the amended return can be found below.
After you click on the year you want to amend, you should select the
option to amend using CD/downloaded software.
Please note that these instructions assume that you prepared your return using TurboTax. Since you did not, you will want to enter the information from your return as originally filed, then proceed starting in Step 3.
https://ttlc.intuit.com/replies/3288565
