Resident and Non–Resident Aliens

You are considered a nonresident alien for any period that you are neither a United States citizen nor a United States resident alien.

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

1. green card holder.

2. substantial presence test:

To meet the substantial presence 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 3 year period that includes the current year and the 2 years immediately before. To satisfy the 183 days requirement, count all of the days you were present in the current year, and one–third of the days you were present in the first year before the current year, and one–sixth of the days you were present in the second year before the current year.

In the IRS Publication 519, US Tax Guide to Aliens, it says that you don’t count any day you are an F1 student towards presence in the US for the substantial presence test. However, after saying students (F1) were one of the “exempt” cases, the “exempt” status were automatically taken away after 5 years.
“You will not be an exempt individual as a student if you have been exempt as a teacher, trainee, or student for any part of more than 5 calendar years unless you establish that you do not intend to reside permanently in the United States and you have substantially complied with the requirements of your visa.”

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