If your e-filed return was rejected (you got a specific reject code), go here instead.
Looking for a prior year return? Go here.
You can amend e-filed returns if they've been accepted; paper-filed returns may be amended once they've been mailed.
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.