# US Tax Residence (Substantial Presence)

Tax residency rule, United States. Page: https://usecountr.com/trackers/tax-us-spt/

## Summary

You become a US tax resident for a calendar year when you are in the United States on at least 31 days of that year and on at least 183 weighted days over three years. The weighted count takes every day of this year, one third of last year's days and one sixth of the days of the year before. A US tax resident is taxed on income from the whole world. The test is in the Internal Revenue Code and the Internal Revenue Service (IRS) applies it.

- Limit: 183 weighted days, with at least 31 days in the current year
- Period: The current calendar year and the two calendar years before it
- Weights: This year in full, last year one third, the year before one sixth
- A day counts when: You are physically in the United States at any time during the day
- Law: Internal Revenue Code section 7701(b)(3)
- Run by: The Internal Revenue Service (IRS)

## Who it applies to

- People who are not US citizens and do not hold a green card, and who spend several months a year in the United States.
- Canadians and Europeans who spend each winter in Florida, Arizona or California.
- Business visitors and remote workers who make many trips to the United States on a visa or under the visa waiver.
- People on work visas such as H-1B or L-1 in the year they arrive or the year they leave.
- Former students and scholars whose years as an exempt individual have run out.

## The rule

The United States taxes its citizens and its residents on income from the whole world. For a person who is not a citizen, section 7701(b) of the Internal Revenue Code gives two ways to become a resident for tax. The first is the green card test: you are a lawful permanent resident at any time in the year. The second is the Substantial Presence Test, which looks only at days.

You meet the Substantial Presence Test for a calendar year when two things are true. You were physically present in the United States on at least 31 days in that year. And the sum of all your days in that year, one third of your days in the year before, and one sixth of your days in the year before that, is at least 183. If you spend 183 days or more in the United States in one year, you meet the test in that year whatever happened before.

For this test the United States means the 50 states and the District of Columbia, and US territorial waters. It does not include Puerto Rico, Guam, the US Virgin Islands or the other US territories, and it does not include US airspace.

Meeting the test is not always the end. If you were in the United States on fewer than 183 days in the year, have your tax home in another country and have closer ties there, you can claim the closer connection exception on Form 8840. If you are also a tax resident of a country that has an income tax treaty with the United States, the tie-breaker rule in the treaty can make you a resident of that country only, and you report that position on Form 8833. A tax home is the main place where you work, or where you regularly live if you have no main place of work.

In the first year you meet the test, your residence normally starts on the first day you are present in the United States in that year, not on 1 January. The IRS calls such a year a dual-status year: you are a nonresident for one part and a resident for the other.

Why it exists: The United States wants people who really live in the country to pay tax like residents, even when they have no green card. Counting only one year would let a person spend five months every year in the country for ever and never become resident. The weights for the two earlier years catch people with a steady pattern of long stays, and the 31-day minimum keeps out people who were in the country a lot in the past and only pass through this year.

## Counting the days

You count days in the United States in three calendar years. Any part of a day counts as a whole day, so both the day you arrive and the day you leave count.

1. Count your days in the United States in the current calendar year. If the number is below 31, you do not meet the test and you can stop.
2. Count your days in the year before and divide by 3.
3. Count your days in the year before that and divide by 6.
4. Add the three numbers. If the total is 183 or more, you meet the test for the current year.
5. Take out any days the law lets you exclude, such as days as an exempt individual, and check whether the total is still 183 or more.
6. If you meet the test, check whether the closer connection exception or a tax treaty applies to you.

How Countr counts it: Countr counts every day on which it sees you in the United States, for the current calendar year and the two years before, and applies the same weights: full, one third, one sixth. It shows the weighted total against 183 and also checks the 31-day minimum for the current year. It starts to warn you 15 days before the limit. Countr cannot know your visa or your reason for being in the country, so it does not take out days as an exempt individual, commuter days from Canada or Mexico, transit stops under 24 hours or days you could not leave for medical reasons. If such days apply to you, your real count is lower than the one Countr shows. Countr also cannot judge a treaty. The 183-day limit of the closer connection exception has its own tracker, US Tax — Closer Connection (Form 8840).

## Examples

### Three winters that add up

Ingrid lives in Norway and has no US visa status other than visitor. She was in the United States on 90 days in 2024, 120 days in 2025 and 130 days in 2026. For 2026 she counts 130 days, plus one third of 120, which is 40, plus one sixth of 90, which is 15. The total is 185. She has more than 31 days in 2026 and 185 is above 183, so she meets the Substantial Presence Test for 2026, even though she never spent half a year in the country.

### A long stay that stays under

Kenji was in the United States on 60 days in 2024, 60 days in 2025 and 150 days in 2026. For 2026 he counts 150, plus 20, plus 10. The total is 180, which is below 183. He does not meet the test for 2026 and stays a nonresident, although 150 days is a longer stay than any of Ingrid's.

### The same number of days every year

A person who spends 120 days in the United States every year counts 120 plus 40 plus 20, which is 180, and never meets the test. A person who spends 122 days every year counts 122, plus 40 and two thirds, plus 20 and one third, which is 183 exactly, and meets the test every year. So for a steady yearly pattern the real limit is 121 days a year, not 182.

## Exceptions

- Days as an exempt individual do not count. This covers students on F, J, M or Q visas, teachers and trainees on J or Q visas, and foreign government staff on A or G visas, other than A-3 and G-5. Exempt here means exempt from counting days, not exempt from tax.
- The student exemption normally ends after you have been exempt in any part of more than 5 calendar years. A teacher or trainee is normally not exempt if they were exempt in any part of 2 of the 6 years before.
- Days on which you commute to work in the United States from your home in Canada or Mexico do not count, if you commute regularly. The IRS treats regularly as more than 75 percent of your workdays.
- A day does not count when you are in the United States for less than 24 hours on your way between two places outside the country. A stop where you hold a business meeting is not transit.
- Days you could not leave because of a medical condition that started while you were in the United States do not count. You claim this, and the student, teacher and athlete exclusions, on Form 8843.
- Days you work as a regular crew member of a foreign ship do not count, unless you also carry on a business in the United States on those days.

## Common misconceptions

- "I can stay 182 days every year and never become a US tax resident." No. Days from the two earlier years are added at one third and one sixth. With the same number of days each year, you reach 183 weighted days at 122 days a year.
- "The test follows my visa. As a tourist I cannot be a tax resident." The test counts days of physical presence. Immigration status matters only for the groups the law names as exempt individuals. A visitor on a B-2 visa or the visa waiver can become a US tax resident.
- "Days in Puerto Rico count as days in the United States." Not for this test. The Substantial Presence Test covers the 50 states and the District of Columbia. US territories such as Puerto Rico, Guam and the US Virgin Islands are outside it.
- "If I meet the test I pay US tax on everything, and nothing can change that." Two things can change it. The closer connection exception applies if you had fewer than 183 days in the year and file Form 8840 on time. A tax treaty tie-breaker can also make you a resident of the other country only.

## Questions and answers

### Does the day I arrive in the United States count?

Yes. You count a day when you are physically in the United States at any time during it. A flight that lands at 11 pm gives you one full day, and the day you fly out counts too.

### Do I count calendar years or the 12 months before today?

Calendar years. The test for 2026 uses your days from 1 January to 31 December 2026, then 2025 and 2024. It is not a rolling 12-month period.

### What happens if I meet the Substantial Presence Test?

You are a US resident for tax for that year, normally from your first day in the country that year. You report income from the whole world on a US resident return, unless the closer connection exception or a treaty applies.

### Do transit stops at a US airport count?

A stop of less than 24 hours on the way between two places outside the United States does not count. If you leave the transit area to attend a meeting, the day counts.

### How many days can I spend in the United States without becoming a tax resident?

It depends on the two years before. With no days in those years you can spend 182 days. With the same pattern every year the most is 121 days. In between, add this year's days, one third of last year's and one sixth of the year before, and stay below 183.

### Does the test apply to green card holders?

Green card holders are already US tax residents under the green card test, so they do not need the day count. The Substantial Presence Test matters for people without a green card.

## Sources

- [IRS, Substantial presence test](https://www.irs.gov/individuals/international-taxpayers/substantial-presence-test)
- [IRS Publication 519, U.S. Tax Guide for Aliens, chapter 1](https://www.irs.gov/publications/p519)
- [IRS, Closer connection exception to the substantial presence test](https://www.irs.gov/individuals/international-taxpayers/closer-connection-exception-to-the-substantial-presence-test)
- [Internal Revenue Code, 26 U.S.C. section 7701(b)](https://www.law.cornell.edu/uscode/text/26/7701)

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Countr is an app for iPhone that counts your days in every country for visa, tax and residency rules, from the photos on your phone and your location. It explains rules and counts days. It does not give legal or tax advice. https://apps.apple.com/app/country-days-tracker-countr/id6810720800