What is Resident Alien?

How it works

The IRS recognises two classes of non-citizens: resident alien and non-resident alien. The classification determines what the US can tax. Resident aliens are taxed exactly like US citizens — worldwide income, Form 1040, all the usual deductions, FBAR and FATCA reporting on foreign accounts.

Two paths into resident-alien status (per PwC US individual residence):

1. Green card test. Lawful permanent residents are resident aliens from the day the green card is issued, and remain so until it is formally relinquished — even if they move abroad indefinitely. Special rules apply to long-time green card holders (8 of the last 15 years) on relinquishment, with potential exit tax under §877A.
2. Substantial Presence Test. 31+ days in the current year and 183+ weighted days across the current year + prior two (1/3 + 1/6 weighting). Pass it without the Closer Connection escape, and you are a resident alien for that calendar year.

A treaty can override the SPT classification. Where the US has a tax treaty with the alien's home country, the treaty's residency tie-breaker (permanent home, vital interests, habitual abode, nationality, mutual agreement) can demote the individual back to non-resident alien status — claimed via Form 8833.

What a resident alien actually files

Same Form 1040 as a US citizen. Reports global salary, capital gains, rental income, dividends, partnership distributions. Claims the foreign tax credit on foreign-source income via Form 1116. Files FBAR (FinCEN 114) if non-US accounts exceed $10,000 in aggregate. Files Form 8938 (FATCA) if specified foreign financial assets exceed thresholds. Owners of foreign corporations file Form 5471; owners of foreign partnerships file Form 8865.

The resident-alien classification often produces lower US tax than non-resident alien status because of greater allowable deductions and lower rates for married filers. Some non-resident aliens deliberately elect resident-alien status when the math works in their favour (the §6013(g) election for non-resident-alien spouses is the classic example).

Examples

• Indian engineer on H-1B. Spent 200 days in the US in 2025 and 200 in 2024 — passes SPT. Resident alien for 2025. Files Form 1040 reporting US salary, plus interest from his Indian savings account, plus the proceeds of an Indian mutual fund (PFIC reporting on Form 8621 may apply). Foreign tax credit on Indian withholding.
• French researcher dual-status year. Arrives 1 March 2026 on a J-1 (exempt for the first two years), so SPT-exempt for 2026 days. Files Form 1040-NR for 2026 as a non-resident alien. After two years, exemption ends; 2028 SPT triggers, he becomes a resident alien — split-year filing: 1040-NR for the period before, 1040 for after.

Common mistakes

• Assuming resident-alien status = US citizen permanently. Resident-alien status ends when the green card is surrendered or the SPT no longer trips (provided no green card). The status is per tax year.
• Missing FBAR and FATCA in year one. Discussed in the callout above. Most expensive paperwork miss for new resident aliens.
• Forgetting the exit tax at green-card surrender. Long-term residents (8 of the last 15 years) trigger §877A on relinquishment if income or net-worth tests are crossed.
• Confusing US tax residency with immigration residency. The two concepts overlap but don't perfectly align — you can be a non-immigrant on a B-1 / B-2 visa and still pass SPT, becoming a US tax resident with no immigration status change.