An alien is any individual who is not a U.S. citizen or a U.S. national. A resident alien is an alien that meets the green card test or substantial presence test.
You are a Lawful Permanent Resident of the United States if you have been issued by the U.S. Citizenship and Immigration Services (USCIS) an alien registration card, Form I-551, also known as a “green card.”
You continue to have U.S. resident status under this test, unless:

- You voluntarily renounce and abandon this status in writing to the USCIS,
- Your immigrant status is administratively terminated by the USCIS, or
- Your immigrant status is judicially terminated by a U.S. federal court.
You will be considered a U.S. resident for tax purposes if you meet the substantial presence test for the calendar year. To meet this test you must be physically present in the United States on at least:
- 31 days during the current year, and
- 183 days during the 3-year period that includes the current year and the 2 years immediately before that, counting:
- All the days you were present in the current year, and
- 1/3 of the days you were present in the first year before the current year, and
- 1/6 of the days you were present in the second year before the current year.
U.S. resident aliens are generally taxed in the same manner as U.S. citizens, on their worldwide income. In addition, they also have additional reporting requirements related to their foreign (non-U.S.) assets.