The Substantial Presence Test for U.S. tax residency is determined by the actual number of days an individual is physically present in the U.S. Specifically, foreign individuals may qualify as U.S. tax residents under this test if they meet the following conditions:
Example:
You visited the U.S. for a specific period over the last few years until 2025. You were present for the following days in the U.S. over the past years:
2025 = 35 days
2024 = 90 days
2023 = 60 days
Your days in the U.S. will be calculated as follows:
Current year (2025): You were present in the U.S. for 35 days in 2025, so all your 35 days will be counted.
Prior year (2024): You spent 90 days in the U.S. in 2024. Only one-third of those 90 days will be counted, which amounts to 30 days.
Two years ago (2023): You spent 60 days in the U.S. in 2023. Only one-sixth of 60 days will be counted, which amounts to 10 days.
If the total calculated days are 183 or more, you pass the substantial presence test and are considered a U.S. tax resident.
In the above example, you were in the U.S. for 35 days during the current year, 30 days in the previous year, and 10 days in the year before that. Thus, your total number of days will be 75 (35+30+10), which is less than the required 183 days. You will therefore not be treated as a U.S. resident for tax purposes.
Example:
Sarah lives and works in Dubai, earning her income entirely outside of the United States. She frequently visits the U.S. to spend time with her fiancé, who is a U.S. citizen.
Let’s assume she spent 180 days in the U.S. each year from 2019 to 2021. For the 2021 test, she would count all 180 days in 2021, 60 days from 2020 (⅓ of 180), and 30 days from 2019 (⅙ of 180). Her total is 270 (180+60+30) days, making her a U.S. tax resident for 2021.