This is exactly what I am thinking.
Problem: I want to view my past tax year document (beit 2017,2018, 2019, etc) and I am already signed into the account that I want to view those documents.
Solution: NOW this is where you actually have to start following the steps 2-6. You have to follow these steps exactly. The reason being, is because you are emulating attempting to file your taxes, and in order to file, you need to register your account on TurboTax, and not just sign in/ sign up for your account and tax year. Once you finish step 6, you'll see a page to register your account, once you do that, you should be able to view and print your previous tax years.
Hope this helps!
