Since resident and nonresident aliens are taxed differently, it is important for you to determine your status. You are considered a nonresident alien for any period that you are neither a United States citizen nor a United States resident alien.

Determining Residency

You are considered a resident alien if you met one of two tests for the calendar year:

• Green Card Test
  If at any time during the calendar year you were a lawful permanent resident of the United States according to the immigration laws, and this status has not been rescinded or administratively or judicially determined to have been abandoned, you are considered to have met the green card test.
• Substantial Presence Test
  To meet this test, you must have been physically present in the United States on at least 31 days during the current year and 183 days during the three year period that includes the current year and the two years immediately prior. To satisfy the 183 day requirement, count all of the days you were present in the current year, 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. Do not count any day you were present in the United States as an "exempt individual" or commute from Canada or Mexico to work in the United States on more than 75% of the workdays during your working period.

An "exempt individual" may be anyone in the following categories:

• An individual temporarily present in the United States as a foreign government-related individual under an "A" or "G" visa, other than individuals holding A-3 or G-5 class visas.
• A teacher or trainee with a "J" or "Q" visa who substantially complies with the requirements of the visa.
• A student with an "F," "J," "M," or "Q" visa who substantially complies with the requirements of the visa.
• A professional athlete temporarily present to compete in a charitable sports event.

Do not count any days you intended to leave but could not leave the United States because of a medical condition that developed while you were in the United States. Even if you meet the substantial presence test, you can be treated as a nonresident alien if you are 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 and you have a closer connection to that country than to the United States. This does not apply if you have applied for status as a lawful permanent resident of the United States or you have an application pending for adjustment of status.

An A-2 visa holder may need to file Form 1040-NR U.S. Nonresident Alien Income Tax Return, as outlined in Memorandum Number AM2011-001, issued by the IRS Office of Chief Counsel as their days of physical presence in the United States are excluded for purposes of the substantial presence test.

Sometimes, a tax treaty between the United States and another country will provide special rules for determining residency for purposes of the treaty. An alien whose status changes during the year from resident to nonresident, or vice-versa, generally has a dual-status for that year and is taxed on the income for the two periods under the provisions of the law that apply to each period. Topic No. 851 Resident and Nonresident Aliens provides more information on the dual-status tax year. Chapter 6 of IRS Publication 519 U.S. Tax Guide for Aliens also contains detailed information on filing in a dual-status tax year.

Which Form to File?

• Nonresident Alien
  you must file Form 1040NR if you are engaged in a trade or business in the United States or have any other U.S. source income on which the tax was not fully paid by the amount withheld. File Form 1040NR with the Internal Revenue Service Center, Philadelphia, Pennsylvania 19255–0215.
• Resident Alien
  you must follow the same tax laws as U.S. citizens. You are taxed on income from all sources, both within and outside the United States.

For more information, please refer to Publication 519. If the tax information you need relating to this topic is not addressed within Publication 519, you may call the IRS International Tax Law hotline at (215) 516–2000. This is not a toll–free number.

Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.