Get your taxes done using TurboTax

Not with any DIY programs ... only some professional tax pros can still efile a prior year return.

 

However if you mailed in the 2020 return the IRS doesn't want you to efile the return as that can cause further processing delays.  Paper returns are taking a year or more to process so all you can do is wait your turn if you mailed in the return properly to the correct address.