Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
IRS Form 1040X is the *Amended* tax return form. For questions about the standard tax return form, use tag "form-1040".
IRS.gov: Form 1040X, Amended U.S. Individual Income Tax Return
5 years, 7 months ago