All amended tax returns must be filed by mail.
When you mail Form 1040-X you should include the following forms:
- The new (amended) Form 1040
- Any forms or schedules that were added or changed as a result of preparing the amendment
It takes the IRS up to 16 weeks to process amended returns. Also, depending on whether the changes affect your numbers, you may also be required to file an amended return with your state.
The mailing address for your state and situation can be found at https://www.irs.gov/pub/irs-pdf/i1040x.pdf. Look under Where to File on page 14.
