Is it possible to use TurboTax to file back taxes? I just got a notice that my 2019 state taxes were never fully submitted.

[Critter-3]

To do a prior year return you have to buy the Desktop program here,

https://turbotax.intuit.com/personal-taxes/past-years-products/

You will need a full Windows or Mac to install it on.

And you will have to print and mail your returns.  So be sure to attach copies of your W2s and any 1099s that have withholding on them.  You have to mail federal and state in separate envelopes because they go to different places.  Get a tracking number from the post office when you mail them for proof of filing.

[fanfare]

What state?

NJ, for example, still lets you fill out and file 2019 NJ return online on the NJ Taxation Website.

(you must have successfully filed a 2018 NJ tax return.)