The Substantial Presence Test is the IRS day-count formula that turns a visitor into a US tax resident. Current year × 1 + prior year × 1/3 + two-prior year × 1/6 ≥ 183 triggers worldwide US income reporting. The Closer Connection Exception (Form 8840) is the most common rescue. Run your dates; see your status.
The Substantial Presence Test (IRC §7701(b)) is the day-count formula by which a non-US person becomes a US tax resident even without a green card. The math: current year × 1 + prior year × 1/3 + two-prior year × 1/6 ≥ 183. Plus the 31-day minimum: at least 31 days in the current year regardless of the weighted total. Once triggered, worldwide income reporting applies for the calendar year of triggering.
The Closer Connection Exception (Form 8840) is the most common rescue. Available where (a) physically present in US <183 days in current year, (b) tax home in a foreign country, (c) closer personal and business connections to a foreign country than to the US. Disqualified if the individual has applied for or taken steps toward US permanent residence. Snowbirds and frequent business travelers depend on this exception annually.
An extra 10 days now costs 1/3 of 10 days next year and 1/6 of 10 days the year after. The formula creates a 3-year rolling window. Snowbirds spending ~150 days/year sit right at the trigger; track airline records.
Even if SPT triggers, a US tax treaty may permit the individual to claim non-US residence under the treaty’s tiebreaker (Article 4 of most modern treaties). Filed via Form 8833. Different mechanic than CCE; works in some cases where CCE fails.
The Residency & Source chapter — the day-count tests, the Closer Connection Exception, treaty tiebreakers, and the pre-immigration tax-planning calendar that runs alongside. Plus a workbook for day-count tracking and the FBAR/8938 reporting framework. Get the chapter and the launch notice.