Can turbo tax help if I want to do an ammendment from 2015, which I hadn't filed thru turbo tax

[LinaJ2018]

Yes, you can amend with TurboTax even if your return was prepared elsewhere.  

1.  You will need to purchase a past year TurboTax desktop program here Past Years Products and 

2.  Recreate your return in exactly the way as how it was filed, then 

3.  Go through the amendment process by following these steps :

     In the program, across the top, go to Federal Taxes / Other Tax Situations / Other Tax Forms- Amend a                            return and select Start to follow step-by-step onscreen instructions.