I filed 2018 federal but rushed and need to correct it and I didn’t do the 2018 state at all. How can I do them now?

[refundfornow4]

Can I do them both now and online?

[NCperson]

@refundfornow4 - will that correction result in an additional refund?  the problem is the IRS window to claim a refund for the 2018 tax year closed on April 15, 2022.   For the State is is vey probable the same deadline applies, so check with your state before you begin this effort. 

if you owe, then you still owe. 

[Critter-3]

Turbo Tax no longer supports the 2018 tax year ... if you need to make a correction and/or file the state return then either get the forms from the taxing authorities and fill them in by hand  OR  seek a local tax pro.  Either way they must be paper filed at this late date.