Substantial presence test

The IRS says a person meets the test if they are physically present in the United States on at least 31 days in the current year and 183 days over the current year and the two years before it. All days in the current year count. Days in the year before count as one-third, and days two years before count as one-sixth.

Some days are not counted. Examples include days as an exempt individual, such as certain students and teachers on qualifying visas, regular commuting from Canada or Mexico, transit of less than 24 hours between two foreign places, and days a medical condition that arose in the United States prevented departure. Excluding exempt days requires filing Form 8843 on time.

Meeting the test is not always the end of the question. The IRS lists the closer connection exception and tax treaties among the elections that can override it. The 183 figure here is part of a weighted US formula, not a universal rule used by other countries.

Not to be confused with

• Tie-breaker rule. A treaty tie-breaker can apply after a person meets the test and is also resident in a treaty country.
• Schengen 90/180 rule. The Schengen rule limits short stays for immigration purposes and does not decide US tax residence.

Sources

• Substantial presence testOfficial guidance
• Determining an individual's tax residency statusOfficial guidance

Related

Countries covered

General

Sources

2 sources

Tax year

Current rules as checked

Review

Not professionally reviewed
Sources checked November 8, 2026