An amended return, Form 1040X, can only be printed and mailed to the IRS if the original tax return was not e-filed. The IRS will take up to 16 weeks or longer to process an amended tax return.
Before starting to amend the tax return, wait for the tax refund to be received or the taxes due to be paid and processed by the IRS.
See this TurboTax support FAQ on amending a tax return originally completed and filed using the 2020 TurboTax editions - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-return/01/27439
The IRS Form 1040-X for amending a 2020 tax return is scheduled to be available on 03/26/2021 (subject to change)
Thanks for the reply. My tax return was e-filed over a month ago. I called and they said there was an error and that I would receive a letter in about 10 weeks. They told me what the error is and so I need to amend my return. I was hoping to do this electronically through TurboTax but it keeps saying the form is not available yet. Do you know when I can amend through Turbotax or is there some other way I can do this electronically? Thanks