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.
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 under 'Where to File' on page 14.
