How to Use a Substantial Presence Test Calculator to Determine Residency

Understanding your residency status for tax purposes is critical, as it directly impacts your tax obligations in the United States. The Substantial Presence Test determines if an individual qualifies as a U.S. resident based on their physical presence over a specific period. This article will explain how to use the Substantial Presence Test Calculator to evaluate your residency status.

Criteria for Counting Days

The Substantial Presence Test calculates the days spent in the United States, as specified in the Internal Revenue Code. To qualify as a resident, an individual must be physically present for at least 31 days during the current year and 183 days over a three-year period, including the current year and the two preceding years. The calculation uses a weighted formula: all days present in the current year are counted fully, one-third of the days from the previous year, and one-sixth from the year before that.

For example, if someone spent 120 days in the U.S. in 2025, 90 days in 2024, and 60 days in 2023, the calculation would be 120 + (90/3) + (60/6) = 150 days, which does not meet the 183-day threshold. This highlights the importance of the weighted allocation of days in determining residency status.

Certain days may be excluded from the calculation. For example, days during which an individual is unable to leave the U.S. due to a medical condition that arose while they were present in the country are not counted. This ensures that residency status is not unfairly impacted.

Weighted Allocation Rules

The Substantial Presence Test considers both the current year’s presence and cumulative presence over the past three years. For example, if an individual was present in the U.S. for 100 days in 2025, 150 days in 2024, and 90 days in 2023, the calculation would be 100 + (150/3) + (90/6) = 150 days. This method emphasizes the importance of tracking travel and presence records, as the weighted formula directly affects residency determination.

Exempt Categories

Certain individuals are exempt from counting days toward the Substantial Presence Test. These exemptions address specific circumstances where U.S. presence is temporary or for a defined purpose.

Students

Students on F, J, M, or Q visas are generally exempt from the Substantial Presence Test for up to five calendar years, recognizing the temporary nature of their stay for educational purposes. Proper documentation, such as Form I-20 or DS-2019, is necessary to substantiate their visa status and the duration of their stay. After the five-year period, students may be subject to the test unless they file Form 8843 to demonstrate that they do not intend to reside permanently in the U.S.

Teachers and Trainees

Teachers and trainees on J or Q visas are exempt from the Substantial Presence Test for up to two of the last six calendar years. To qualify, they must not have been exempt as students, teachers, or trainees for any part of two of the preceding six years. Form DS-2019 is required to verify their status, and filing Form 8843 annually is necessary to claim this exemption.

Medical Condition

Days spent in the U.S. due to a medical condition that arises after arrival may be excluded from the Substantial Presence Test. This exemption does not apply to pre-existing conditions. Filing Form 8843 with medical documentation is required to claim this exclusion, specifying the condition and the period it prevented departure.

Determining Residency Status

Residency status for tax purposes involves more than physical presence. An individual’s tax home — typically their primary place of business or employment — may also factor into the determination. For those who travel frequently or have multiple work locations, maintaining a tax home outside the U.S. can influence their residency status.

The closer connection exception allows individuals who meet the Substantial Presence Test to be treated as non-residents if they can demonstrate stronger ties to a foreign country. Evidence such as a permanent home, family members, or personal belongings located abroad must be provided, along with filing Form 8840.