If you’ve already filed your taxes, you don’t need to amend to get your stimulus payment, go here for more info.
You can amend e-filed returns if they've been accepted; paper-filed returns may be amended once they've been mailed.
If your e-file is still pending, you won't be able to make changes until the IRS either accepts or rejects it. Don't know your e-file status? Here's how to look it up.
Select your tax year for amending instructions:
Keep in mind: You have 3 years from the date you filed your return or 2 years after you paid the tax due (whichever is later) to file an amendment.