Substantial Presence Test

An IRS test used to determine whether a foreign national is classified as a "resident alien" for U.S. tax purposes. The test counts days of physical presence over a 3-year period using a weighted formula: all days in the current year + 1/3 of days in the prior year + 1/6 of days two years prior. F-1 students are exempt from counting days for the first 5 calendar years of presence. After passing the test, you file taxes as a resident alien using Form 1040.