I have seen the post for this error. We have only mailed Fed before because we owed. Both the AIG and PIN pulled from last year via Turbo Tax and we verified off last years return. This is the first year we are efiling as previous years we owed money. Should we use 0 for the AIG then?
No, Last year's AGI is from the Form1040 on page 1, line 8b. It does not matter whether you paper filed or e-filed your return; your AGI would not change.
For some reason, the IRS has a different AGI in their database. You need to find out what number they have so you can e-file.
Start by getting a free IRS transcript for your 2019 return. (If you're filing jointly in 2020 but your spouse filed their own return in 2019, also get a transcript for your spouse).
On your transcript, look for ADJUSTED GROSS INCOME (you may need to look on page 2). This is the number in the IRS database. Make sure the AGI you enter matches this number exactly.
If you're unable to order an IRS transcript, you can try entering 0 as your AGI, assuming you haven't already gone that route.
You can also opt to file a paper return if you cannot successfully e-file your return.