Because residents and nonresident aliens are taxed differently, it's important for you to determine your tax status.
You're considered a nonresident alien for any period that you're neither a U.S. citizen nor a resident alien for tax purposes.
You're considered a resident alien for a calendar year if you meet the green card test or the substantial presence test for the year.
You're considered to have met the green card test, and are therefore a resident alien, if at any time during the calendar year you are a lawful permanent resident of the United States according to the immigration laws, and this status hasn't been revoked or administratively or judicially determined to have been abandoned.
You satisfy the substantial presence test, and are therefore treated as a resident alien for a calendar year, if you have been physically present in the United States on at least:
For purposes of the substantial presence test, the term United States doesn't include U.S. territories or U.S. airspace. The United States includes the following areas:
Even if you meet the substantial presence test, you may still be treated as a nonresident alien if you're present in the United States for fewer than 183 days during the current calendar year, you maintain a tax home in a foreign country during the year, you have a closer connection to that country than to the United States, and you timely file a Form 8840, Closer Connection Exception Statement for Aliens claiming you have a closer connection to a foreign country or countries. You can't claim a closer connection to a foreign country if you've applied, or took other steps during the year, to change your status to that of a lawful permanent resident of the United States, or you have an application pending for lawful permanent resident status (green card). Sometimes, a tax treaty between the United States and another country will provide special rules for determining residency for purposes of the treaty. If you claim to be solely a resident of a tax treaty jurisdiction, file Form 8833, Treaty-Based Return Position Disclosure Under Section 6114 or 7701(b). See Publication 519, U.S. Tax Guide for Aliens for more information about the substantial presence test.
Even if you don't meet the green card test or substantial presence test for the current year (for example, 2023), or the prior year (2022), and you did not choose to be treated as a U.S. resident for part of the prior year (2022), but you meet the substantial presence test in the following year (2024), you can choose to be treated as a U.S. resident alien for part of the current year (2023) and be taxed as a dual-status alien for the current year (2023) by making the First-Year Election or, if you are a nonresident alien married to a U.S. citizen or resident alien, and you and your spouse make an election for you to be treated as a resident alien for the entire calendar year and all subsequent years until terminated. See Chapter 1 of Publication 519 PDF for more information.
If your status changes during the year from resident alien to nonresident alien or vice versa, you generally have a dual-status tax year. This usually happens in the year when you arrive in or depart from the United States. Your tax on the income for the two periods will differ under the provisions of the laws that apply to each period. See Publication 519 for more information about dual-status aliens.
If you're a nonresident alien who is engaged in a trade or business in the United States, you must file a return and report all of your income from U.S. sources, both from the trade or business and any U.S. source non-effectively connected income for which amounts have been withheld. If you're not engaged in a U.S. trade or business and have any U.S. source income on which the amount of tax withheld didn't fully satisfy the tax due, or you seek to claim a refund of overwithheld or overpaid tax, you must also file a Form 1040-NR. See the Instructions for Form 1040-NR PDF for more information.
Resident aliens must follow the same tax laws as U.S. citizens. If you're a resident alien, you must report your worldwide income from all sources, that is, income from both within and outside the United States. You'll file a Form 1040, U.S. Individual Income Tax Return or Form 1040-SR, U.S. Tax Return for Seniors.
For any due date that falls on a Saturday, Sunday, or legal holiday, the due date is delayed until the next business day.