If you already filed you will need to amend.
You can amend returns that have been accepted by the IRS. If your return is pending, you won't be able to make any changes until it's accepted or rejected by the IRS. If you don't know your e-file status, we can help you check it.
Be sure to print out a copy (or save a pdf copy) before making any changes.
Select a tax year for specific 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 amended return, which means you don't have to get it done by the April 15 filing deadline.