Of course.  Just use a single zero for the AGI. 

According to IRS, all paper 2020 returns mailed before 2022 have been entered, and therefor, should show up on the

Where's My Refund" tool, if you are due a refund.

@mjonesg58 

The IRS hasn't accepted my 2020 paper return that was mailed about April 27, 2022 and the "Where's my refund" has no information on it. Do I need to do anything special to file my 2021 return before the IRS accepts my 2020 return? I'm worried that if I wait much longer I will be required to file my 2021 return by paper and I definitely want to file electronically. Do you know what the deadline is for that? please advise. TY

@mjonesg58 You can use TurboTax to e-file a 2021 tax return at any time on or before October 17, 2022.  After that date the 2021 tax return can only be printed and mailed using TurboTax.

Since the IRS has not processed your 2020 federal tax return, in the File section of the online editions on Step 3 after you select to e-file the return you will be asked to provide the 2020 AGI.  Enter a 0 (zero) for the 2020 AGI so that you can e-file the 2021 tax return.

@mjonesg58  with paper returns, the taxpayer is never notified of acceptance.  if not accepted and processed nothing will show up in WMR.   Did you use a mailing method where you got proof of delivery? assuming the IRS got it since you say you didn't mail it until 2022 (not 2021)  it might be sitting in a mail bag at some IRS center. it could take 6 months or more before the IRS gets to it.

you can e-file 2021, just use 0 (ZERO) for the prior year's adjusted gross income. However, due to the late filing of 2020, if you asked that the overpayment be applied to 2021, that may create a problem.  the 2021 1040 e-filing deadline is 10/17/2022