How do I amend my rejected 2018 federal tax return? Online system doesn't work, and no instructions on how to amend by mail?

If your return was rejected by the IRS, you would not Amend but fix and resubmit your return to the IRS. If you received an ACTION NEEDED! email from turbotax@intuit.com, it'll give you a brief explanation of your reject and how to update it. You can also sign in to your TurboTax account and select Fix my return to see your reject code and explanation.

Not all rejections will have explicit guides to fixing the information. If you aren't guided to your solution, search for the item causing your rejection and go to that section (you might also be able to find your rejection in the list of the 10 most “popular” IRS rejects, this will be in the link). Make the change and select File in the left-hand menu. Follow the onscreen instructions to either e-file your return or file by mail.

Please see the link below for more instructions:

How do I fix a rejected return?