After you file

I would recommend you e-file an amended return as soon as the original return is completely finished- all payments have cleared the banks,  Please:

• Save a copy of the original return before doing an amended return.
• See how to file an amended return.
• Follow your amend at track an amended return 
• See Can I e-file my amended state return?

You will owe money and want to make that payment by April 15 so there is no penalty or interest. In addition, you may need to file a state return. If you must paper file, tracking is recommended.