I've printed my returns (Fed and State) but haven't yet filed them. Can I re-open the returns in Turbotax to, say, make Roth IRA contributions?

[DoninGA]

To access your current or prior year online tax returns sign onto the TurboTax website with the userID you used to create the account - https://myturbotax.intuit.com/

When you sign onto your online account and land on the Tax Home web page, scroll down and click on Add a state. 

This will take you back to the 2019 online tax return so that you can add, edit or delete any information.