You cannot efile an 2019 amended return thru turbotax in 2020. I filed a 2019 amended tax return in April 2020 on paper because turbotax wouldnt allow it electronically. I filed an extension for 2020 to wait until the 2019 amendment was processed. It took until Aug for the IRS to process the 2019 amended return. I then filed my 2020 tax return so that when my 2020 tax return was processed, the amended 2019 tax return was in the system and there would be no inconsistencies.
