US Substantial Presence Test: how the SPT formula works for non-US citizens

The Substantial Presence Test does not apply to US citizens or green card holders. US citizens owe US tax on worldwide income regardless of where they live. Green card holders are automatically US tax residents. The SPT is irrelevant to both groups.

The SPT applies to non-US citizens and non-green-card holders who spend time in the United States. If you are a foreign national who periodically travels to the US for work, extended stays, or family visits, the SPT is what determines whether you are taxed as a US resident alien or a nonresident alien.

The difference matters. A resident alien pays US tax on worldwide income, the same as a US citizen. A nonresident alien pays US tax on US-sourced income only.

Jetseen helps you track days. Always consult a qualified tax professional for advice specific to your situation.

The two-test sequence

The SPT requires passing both tests. Passing only one is not enough.

Test 1: At least 31 days in the US during the current calendar year. Fewer than 31 days this year means you do not meet the SPT for that year. No further calculation needed.

Test 2: A weighted 3-year total of 183 days or more. This is where most people miscalculate. The 183-day threshold is not your current-year day count. It is a weighted sum across three years:

• Current year days count in full
• Days from one year prior count at 1/3
• Days from two years prior count at 1/6

If the combined weighted total reaches 183 or more, you meet the SPT.

The weighted formula: two worked examples

Example 1: 120 days each year for three consecutive years

| Year | Days present | Weighting | Weighted count | |---|---|---|---| | Current year | 120 | × 1 | 120 | | Prior year | 120 | × 1/3 | 40 | | Two years prior | 120 | × 1/6 | 20 | | Total | | | 180 |

180 < 183. You do not meet the SPT.

Example 2: 150 days this year, 90 last year, 60 the year before

| Year | Days present | Weighting | Weighted count | |---|---|---|---| | Current year | 150 | × 1 | 150 | | Prior year | 90 | × 1/3 | 30 | | Two years prior | 60 | × 1/6 | 10 | | Total | | | 190 |

190 ≥ 183. You meet the SPT. You are a US tax resident for the current year.

The weighted total is a formula result, not a count of physical days. 190 weighted days does not mean you were in the US for 190 days. This is a calculation artifact from the IRS methodology.

Source: IRS Substantial Presence Test page (reviewed 14 March 2026), IRS Publication 519 (2025 edition), IRS Tax Residency Status Examples

Days that do not count

Five categories of days are excluded from the SPT count:

1. Commuter days. You commute from a regular residence in Canada or Mexico to work in the US, and more than 75% of your workdays in the period involve that cross-border commute.

2. Transit days. You pass through the US between two foreign destinations, spending fewer than 24 hours in the country.

3. Foreign vessel crew days. You are a regular crew member on a foreign vessel engaged in transport between the US and a foreign country or US possession.

4. Medical condition days. You are unable to leave because of a medical condition that arose during your US stay. The condition must have developed after you entered. If you traveled to the US specifically for medical treatment, these days are not excluded.

5. Exempt individual days. Certain visa categories exclude all US days from the SPT count. See the next section.

Source: IRS Substantial Presence Test page, IRS Publication 519

Exempt individuals

Being an "exempt individual" means all your US days are excluded from the SPT count during the period of exempt status. Four categories:

| Category | Visa / status | Time limit | |---|---|---| | Foreign government officials | "A" or "G" visa (not A-3 or G-5 household staff) | No statutory limit | | Teachers and trainees | "J" or "Q" visa, substantially complying with visa terms | Max 6 calendar years total | | Students | "F," "J," "M," or "Q" visa, substantially complying with visa terms | 5 calendar years; extendable with evidence of non-permanent US residence intent | | Professional athletes | Any status | Only days competing in qualified charitable sports events where net proceeds go to charity, events are volunteer-operated, and a charitable organization is the beneficiary. Practice, travel, and promotional days do not count. |

After 5 calendar years, students must demonstrate they do not intend to reside permanently in the US to continue the exclusion. The teacher/trainee 6-year cap is reduced in certain cases where a foreign employer paid full compensation during prior exempt years.

Source: IRS Substantial Presence Test page, IRS Publication 519

The closer connection exception

Even if you technically meet the SPT, you can still be treated as a nonresident alien by claiming the closer connection exception. All four conditions must be satisfied:

1. Fewer than 183 physical US days in the current calendar year. If you were in the US for 183 or more days this year, you cannot claim this exception. There are no exceptions to this bar.

2. A tax home in a foreign country for the entire current calendar year. Your tax home is the location of your primary business activity or employment. If you have no fixed business location, it is your regular place of abode.

3. A closer connection to that foreign country than to the US. The IRS evaluates significant contacts, including: the country listed on your official documents; location of your permanent home; location of your family; location of your personal belongings; location of your financial accounts; where you hold your driver's license; where you are registered to vote; and your social, cultural, and charitable affiliations.

4. No pending US immigration application for lawful permanent residence. Filing Form I-485, I-130, I-140, ETA-750, I-508, or OF-230 disqualifies you.

To claim the exception, file Form 8840 (Closer Connection Exception Statement for Aliens) by the due date of your US tax return, including extensions. If you file a return, attach Form 8840 to it. If no return is required, mail Form 8840 to the IRS Center in Austin, TX 73301-0215. Failing to file means you lose the exception unless you can demonstrate clear and convincing evidence of a reasonable attempt to comply.

Source: IRS Closer Connection Exception page, IRS Publication 519, IRS Form 8840, Taxes for Expats

Form 8840 vs Form 8843: not the same form

These two forms are frequently confused:

| Form | Purpose | Who files | |---|---|---| | Form 8840 | Closer Connection Exception Statement for Aliens | Non-citizens who technically meet the SPT but have fewer than 183 physical US days and claim closer connection to a foreign country | | Form 8843 | Statement for Exempt Individuals and Individuals With a Medical Condition | Exempt individuals (students, teachers, athletes, government officials) claiming their US days should be excluded from the SPT count; also filed to claim medical condition day exclusions |

A student on an F-1 visa in year 2 of their studies files Form 8843. A consultant on a business visa who spent 150 days in the US and wants to claim nonresident status files Form 8840. These forms solve different problems.

Source: IRS Publication 519, IRS Form 8840

What happens if you meet the SPT

You are classified as a resident alien for US tax purposes. You owe US tax on worldwide income and gains. You file Form 1040.

If you arrive or depart the US partway through the year, you may have a dual-status year: resident for part of the year, nonresident for the rest. A dual-status return is more complex and typically requires professional preparation.

Your residency starts on the first day you were physically present in the US during the year you meet the SPT. If you entered February 5 and your weighted total meets the threshold, your US tax residency begins February 5, not January 1.

Source: IRS Residency Starting and Ending Dates, IRS Publication 519

Day tracking and documentation

The SPT is exact. One additional US day can push your weighted total across the 183-day threshold. Excluded days (transit, medical, commuter, exempt individual) require contemporaneous documentation. The burden of proof sits with you if the IRS asks.

Jetseen tracks US days as one of 12+ built-in rule engines. Use the Trip Impact Simulator to check whether a planned US trip would affect your SPT balance before you book. Export your travel records as a CSV for your tax advisor at year-end. Your data stays on your device.

Calculate Your Days at jetseen.com/calculator.

FAQ

Does the 183-day rule mean 183 physical days in the US?

Not exactly. 183 is the threshold for the weighted 3-year formula, not simply your current-year day count. 120 days per year for three consecutive years produces a weighted total of 180, which does not meet the SPT. Always run the full formula before drawing conclusions.

Can I spend fewer than 183 days this year and still be a US tax resident?

Yes. If your weighted total across three years reaches 183, you meet the SPT. Someone who spent 130 days this year, 150 days last year, and 120 two years ago has a weighted total of 130 + 50 + 20 = 200. They meet the SPT despite never spending 183 days in a single year.

What is Form 8840 and when do I need it?

Form 8840 is the Closer Connection Exception Statement for Aliens. You file it to claim nonresident status despite technically meeting the SPT. The requirement is fewer than 183 physical US days in the current year, a tax home in a foreign country, and a closer connection to that country than to the US. File by the due date of your US tax return.

Does the SPT apply to US citizens living abroad?

No. US citizens owe US tax on worldwide income regardless of where they live. The SPT does not determine their status.

What is the difference between a resident alien and a nonresident alien?

A resident alien pays US tax on worldwide income and files Form 1040. A nonresident alien pays US tax only on US-sourced income, such as wages from US-based work or US rental income, and files Form 1040-NR. The SPT is the test that determines which category applies for non-US citizens in a given year.

Sources

1. IRS — Substantial Presence Test (reviewed 14 March 2026): https://www.irs.gov/individuals/international-taxpayers/substantial-presence-test
2. IRS Publication 519 — U.S. Tax Guide for Aliens (2025 edition): https://www.irs.gov/publications/p519
3. IRS — Closer Connection Exception: https://www.irs.gov/individuals/international-taxpayers/closer-connection-exception-to-the-substantial-presence-test
4. IRS — Tax Residency Status Examples: https://www.irs.gov/individuals/international-taxpayers/tax-residency-status-examples
5. IRS — Residency Starting and Ending Dates: https://www.irs.gov/individuals/international-taxpayers/residency-starting-and-ending-dates
6. IRS — Topic No. 851: Resident and Nonresident Aliens: https://www.irs.gov/taxtopics/tc851
7. Taxes for Expats — Form 8840 guide (2026): https://www.taxesforexpats.com/articles/non-us-citizens/irs-form-8840-closer-connection-exception-to-avoid-us-taxation.html
8. IRS Form 8840 (PDF): https://www.irs.gov/pub/irs-pdf/f8840.pdf

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Jetseen helps you track days. Always consult a qualified tax professional for advice specific to your situation.