Once the return if efiled, you must amend to make any changes.
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.