U.S. taxes for newcomers: resident or nonresident?

Step 1 — Know that tax status is not immigration status

Immigration law talks about immigrants, nonimmigrants and undocumented people; tax law uses only residents and nonresidents (IRS — Introduction to residency). The two don’t line up: the IRS says even an undocumented person who meets the substantial presence test (Step 3) is treated as a U.S. resident for tax purposes (IRS — Introduction to residency).

IRS forms say “resident alien” and “nonresident alien.” For the IRS, “alien” simply means an individual who isn’t a U.S. citizen (IRS — Topic 851). On 4Livo we say “resident (or nonresident) for tax purposes.”

Why it matters: in general, residents are taxed like U.S. citizens, on their worldwide income, while nonresidents are generally taxed only on U.S.-source income and income connected with a U.S. trade or business (IRS — Introduction to residency). A noncitizen is a nonresident unless they meet the green card test or the substantial presence test (IRS — Determining tax residency).

Step 2 — Look at the green card test

A person who is a lawful permanent resident at any time during the calendar year is a resident for federal tax purposes; people generally have this status if USCIS issued them a Permanent Resident Card, Form I-551 (IRS — Green card test). If only the green card test is met, residency starts on the first day that year in the U.S. as a permanent resident; for a green card received abroad, on the first day in the U.S. after receiving it (IRS — Residency starting and ending dates).

A warning from the IRS: under immigration law, a permanent resident who is required to file a tax return as a resident and doesn’t may be regarded as having abandoned that status, and may lose it (IRS — Publication 519). For questions about your green card, see our guide to free immigration legal help.

Step 3 — Understand the day count: the substantial presence test

Without a green card, the IRS counts the days you were physically in the U.S. The test is met for a year with at least (IRS — Substantial presence test):

• 31 days in the current year, and
• 183 days over 3 years, counting all the days in the current year, one-third of the days in the year before, and one-sixth of the days in the year before that (IRS — Substantial presence test).

The IRS page has a worked example and two more rules (IRS — Substantial presence test):

• A day counts if you are in the U.S. at any time during it, even for part of the day.
• Some days don’t count, for example less than 24 hours in transit between two places outside the U.S., days you couldn’t leave because of a medical condition that began here, and days as an “exempt individual” (Step 4) (IRS — Substantial presence test).

Keep a simple list of the dates you arrive and leave. For the official record of your arrival, see our guide to the I-94 arrival record.

Step 4 — Check the exceptions: “exempt individuals” and others

“Exempt individual” does not mean exempt from U.S. tax. It means some of your days in the U.S. are not counted for the substantial presence test (IRS — Substantial presence test). The IRS lists four groups: foreign government-related individuals on an A or G visa (except A-3 and G-5), teachers or trainees on a J or Q visa, students on an F, J, M or Q visa (both only if they substantially comply with their visa’s requirements), and professional athletes at a charitable sports event (IRS — Substantial presence test). Immediate family members on the same visa are included, and time limits apply: for example, students generally can’t stay exempt beyond 5 calendar years unless certain conditions are met (IRS — Topic 851).

Form 8843. Anyone who leaves out days as an exempt individual or because of a medical condition must include Form 8843 with their tax return, or send it on its own by the return’s due date if they don’t have to file. Without a timely Form 8843, those days generally can’t be excluded (IRS — Substantial presence test). For nonresident students and scholars, the IRS says no minimum amount of income triggers a filing requirement (IRS — Foreign students and scholars).

Other exceptions. A “closer connection” to another country can make someone a nonresident even after meeting the day count, under strict conditions that include a timely Form 8840; it isn’t available to anyone who applied for a green card, or had an application pending, during the year (IRS — Topic 851). Tax treaties can also have their own residency rules (IRS — Dual-status individuals). 4Livo doesn’t interpret treaties; see the IRS tax treaties page.

Step 5 — Understand your arrival year: “dual status”

The IRS says you can be both a nonresident and a resident in the same tax year, usually the year you arrive in or leave the U.S., and then you file a dual-status return (IRS — Determining tax residency). “Dual status” is about tax residency only, not citizenship (IRS — Publication 519).

Under the substantial presence test, residency generally starts on the first day in the U.S. that year; for exempt individuals it may start later than their arrival, because exempt days don’t count (IRS — Residency starting and ending dates).

Some choices can override the tests, such as the “first-year choice” or treating a nonresident spouse as a resident (IRS — Determining tax residency). Chapter 1 of Publication 519 explains their conditions; once made, the first-year choice can’t be revoked without IRS approval (IRS — Publication 519).

Step 6 — Match the form to the status

• Residents file Form 1040 or Form 1040-SR and report their worldwide income (IRS — Topic 851).
• Nonresidents who must file use Form 1040-NR, U.S. Nonresident Alien Income Tax Return (IRS — Taxation of nonresident aliens).
• Dual-status filers use the form for their status on the last day of the year, plus a statement for the other part of the year (IRS — Publication 519).

Due dates. For residents, generally April 15 (IRS — Taxation of U.S. residents). For nonresidents, generally April 15 with wages subject to U.S. income tax withholding, and June 15 without such wages and without a U.S. office or place of business (IRS — Taxation of nonresident aliens).

Money back home. Residents report income earned outside the U.S. too, such as interest or rent (IRS — Taxation of U.S. residents). U.S. tax residents may also have to report foreign financial accounts on an FBAR (FinCEN Form 114) when their total value was over $10,000 at any time during the year (IRS — FBAR), and some must report foreign assets on Form 8938 (IRS — New immigrants).

State taxes are separate. Many states, counties and cities also tax income, and USA.gov shows how to find your state’s tax agency (USAGov — State and local taxes).

Step 7 — Put the right number on your return

Tax returns need a taxpayer identification number: a Social Security number (SSN), or, for someone who isn’t eligible for one, an Individual Taxpayer Identification Number (ITIN) (IRS — Publication 519). A spouse and each dependent must also have an SSN or ITIN to be claimed (IRS — Taxation of U.S. residents). Our guides to the Social Security number and the ITIN explain how to get them.

Step 8 — Know your rights before you file

The Taxpayer Bill of Rights includes the right to clear explanations of the tax laws and to be spoken to in a way you can easily understand (IRS — Taxpayer Bill of Rights). Before you file, read chapter 1 of Publication 519 in the edition for that tax year; the current one is for 2025 returns (IRS — Publication 519).