You can file Form 1040-X, Amended U.S. Individual Income Tax Return electronically with tax filing software to amend your Form 1040, 1040-SR, 1040-NR, or 1040-SS for the current or two prior tax periods. If amending a prior year return originally filed on paper, then the amended return must also be filed on paper. See Form 1040-X, Amended U.S. Individual Income Tax Return: Frequently asked questions for more information. Even if you filed your original return electronically, you still have the option to file a paper version of the Form 1040-X and should follow the instructions for preparing and filing the paper form.