For a current year return, there is no additional cost to file a Form 1040X as long as you aren't adding additional information that will cause an upgrade (i.e. if you are in Free Edition, but need to amend to add self employment income, then you will need to pay for the upgrade to Self-Employed). Its possible you may have to upgrade to PLUS to amend a prior year return if you did not save the .tax file if you are a Free Edition user.
You can follow the instructions below to get started. Reminder: Amended returns must be printed and mailed, so make sure you have access to a printer. Also, they can take up to 16 weeks to process.
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