For tax purposes, an alien is an individual who is not a U.S. citizen. Aliens are classified as nonresident aliens and resident aliens. Publication 519 will help you determine your status and give you information you will need to file your U.S. tax return. Current revision Publication 519 (Print version PDF | eBook EPUB) Recent developments Changes to 2023 Publication 519 -- 11-APR-2024 2023 Publication 519, update to chapter 4 -- 29-FEB-2024 Other items you may find useful All Revisions for Publication 519 Foreign Agricultural Workers on H-2A Visas About Publication 54, Tax Guide for U.S. Citizens and Resident Aliens Abroad About Publication 463, Travel, Entertainment, Gift, and Car Expenses About Publication 501, Dependents, Standard Deduction, and Filing Information Other Current Products Related items About Form 1040-C, U.S. Departing Alien Income Tax Return About Form 1040-ES (NR), U.S. Estimated Tax for Nonresident Alien Individuals About Form 1040-NR, U.S. Nonresident Alien Income Tax Return About Form 1040-X, Amended U.S. Individual Income Tax Return About Form 1042-S, Foreign Person's U.S. Source Income Subject to Withholding About Form 1116, Foreign Tax Credit (Individual, Estate, or Trust) About Form 2063, U.S. Departing Alien Income Tax Statement