Overview
For professionals with extraordinary ability on an O-1A visa or pursuing EB-1A classification, U.S. taxes depend primarily on tax residency rather than immigration category. The IRS generally treats non-U.S. citizens as nonresidents for tax purposes, unless they meet the “green card test” or the “substantial presence test” for the calendar year (IRS, Determining an individual’s tax residency status), as will be discussed later. In addition to tax residency, most who work in the U.S. must understand the following mechanics: Form W-4 withholding, Form W-2 wage reporting, Social Security and Medicare taxes, estimated taxes, U.S. state taxes, and how foreign income and other cross-border items are handled.
None of these rules are determined simply by the visa stamp in your passport, which surprises many professionals arriving in the United States for the first time.
Tax Residency Is Not the Same as Immigration Status
Perhaps the single most useful takeaway in this article: U.S. tax residency for visa holders is separate and distinct from immigration status.
Holding an O-1A status does not automatically determine how taxes are filed. Having an EB-1A petition approval does not, in itself, make one a permanent resident or U.S. tax resident; the EB-1A is an immigrant classification and green card pathway, so EB-1A green card taxes typically apply only once lawful permanent residence actually begins, which arrives at the green card step, and not the I-140 petition step. So, for those who adjust their status inside the U.S., permanent residence generally begins the day USCIS approves the adjustment application (I-485); through consular processing abroad, it generally begins the day of admittance into the U.S. through the immigrant visa (IRS, Residency starting and ending dates).
The IRS applies its own analysis when determining whether an individual is a U.S. tax resident, using two tests that are applied calendar year by calendar year: the green card test and the substantial presence test (IRS, Determining an individual’s tax residency status). The first year in the country can be the trickiest to determine, since it is possible to be a nonresident for part of the year and a resident for the rest, which the IRS calls a “dual-status year.” For the first year of residency, Publication 519, U.S. Tax Guide for Aliens, exists specifically to help non-citizens determine whether or not they are residents and what they are required to file (IRS, Publication 519).
Where the green card test is the only test that applies, the IRS treats the first day of green card status as the first day of U.S. tax residency. Where both tests are met in the same calendar year, however, the residency starting date is the earlier of the two: the first day of presence in the year the substantial presence test was met, or the first day of presence as a lawful permanent resident. In addition, where the individual was a U.S. tax resident during any part of the preceding calendar year and is a resident for any part of the current year, residency is treated as beginning on the first day of the current year (IRS, Residency starting and ending dates). This distinction is significant for many EB-1A applicants, since an individual who has lived and worked in the U.S. on an O-1A for several years will already satisfy the substantial presence test; where such a person’s adjustment of status is approved in September, U.S. tax residency will not have begun in September, but earlier in the year, and frequently on January 1. The green card marks a change in immigration status, but it does not necessarily mark the date on which U.S. tax residency began.
Since tax residency is so dependent on timing (i.e. arrival date, days of presence, and whether there were previous years in the U.S.) and other personal factors, it is a good idea to bring in a qualified tax professional to confirm tax residency and requirements.
Resident Alien vs. Nonresident Alien
For tax purposes, the IRS considers “non-citizens” as occupying one of two categories: a “resident alien”, who meets either the green card test or the substantial presence test for the year, or a “nonresident alien,” who meets neither test (IRS, Topic no. 851). The resident alien vs. nonresident alien distinction shapes most of what follows: the form you file, what income can be taxed, and how employers withhold funds from your paycheck for taxation purposes.
Of these, the scope of taxable income is often the most consequential. A resident alien is generally taxed on worldwide income, from all sources both inside and outside the United States, under the same rules that apply to U.S. citizens (IRS, Taxation of U.S. residents), while a nonresident alien is generally taxed only on income effectively connected with a U.S. trade or business and on certain U.S.-source income (IRS, Taxation of nonresident aliens). For a professional arriving from abroad, this is the practical significance of crossing the line from nonresident to resident: income earned outside the United States may enter the U.S. tax base for the first time.
These distinctions are reflected in payroll from the outset: the IRS instructs employers to identify non-citizens on their staff, separate them into resident aliens and nonresident aliens under Internal Revenue Code section 7701(b), treat resident aliens the same as U.S. citizens for income tax withholding, and apply special rules to nonresident aliens (i.e. completing Form W-4 differently and having employers calculate withholding using a different method) (IRS, Aliens employed in the U.S.). Tax filing differs among residents and nonresidents too. As a general matter, nonresident filers use Form 1040-NR while resident aliens file the same Form 1040 as U.S. citizens (although the specific category that applies to a given resident is best confirmed with a tax professional).
A dual-status year, where one counts as a nonresident for a part of the year and a resident for the other, comes with its own filing complications, which are discussed in Publication 519. Tax treaties are a separate matter: depending on the treaty between the U.S. and one’s home country, they can change whether, and how much, U.S. tax applies to certain income. Since treaties introduce highly technical requirements, it is strongly recommended that they be reviewed with a qualified tax professional.
The Substantial Presence Test
The substantial presence test is the one that most temporary visa holders encounter. Simply put, the IRS counts the number of days physically spent in the country. You generally meet the test for a calendar year if both of the following are true (IRS, Substantial Presence Test):
- You were present in the United States for at least 31 days during the current calendar year.
- Your weighted total over the current year and the two preceding years reaches 183 days, counting:
- all days in the current year,
- 1/3 of the days from the previous year, and
- 1/6 of the days from the year before that.
Without familiarity with the test, the 1/3 and 1/6 weighting of the previous years can be misleading. In addition, not every day of physical presence counts toward the test. Certain individuals, including some students and exchange visitors, may be permitted to exclude days of presence under IRS rules, while O-1 visa holders generally count all days spent in the United States (IRS, Publication 519). Simply running the numbers based on a cursory understanding of the test is not advisable: details matter, and the stakes are too high. Bring your actual travel history to a qualified professional for the precise calculation.
Green Card Test and EB-1A Context
The green card test is more straightforward on paper: if you are a lawful permanent resident under U.S. immigration law at any point during the calendar year, generally meaning that USCIS has issued you a Permanent Resident Card, then the green card test is met (IRS, U.S. tax residency, Green card test). The nuance that EB-1A readers must bear in mind for the green card test is timing. An approved EB-1A petition is merely a milestone in the green card process, and is not the same thing as holding permanent residence; an EB-1A approval does not on its own satisfy the green card test and activate tax status.
What determines when residency begins under the green card test is the precise date on which permanent residence actually starts, which depends on whether the green card is obtained through adjustment of status inside the U.S. or consular processing abroad, as set out above.
Payroll Basics: W-4, W-2, and Payroll Taxes
Two forms run the show for salaried employees, regardless of whether they are a resident or nonresident. Form W-4 is the one that allows employers to withhold the correct amount of federal income tax from each paycheck (IRS, About Form W-4). Form W-2 is the one employers send for the year-end reporting of wages and income, Social Security, and Medicare tax that were withheld (IRS, About Form W-2).
For founders who are new to the U.S., the W-4 is often the first unfamiliar tax document they encounter. Many arrive from countries where payroll withholding is automatic, and employees are not required to complete any form, so becoming familiar with the W-4 early is worthwhile, especially since founders who run payroll for their own company straddle both the employer-employee sides of the process. The responsibility runs both ways: the employee completes the form, while the employer is responsible for knowing whether that person is a resident or nonresident for tax purposes, since that classification determines withholding rules (IRS, Aliens employed in the U.S.).
Founders should be familiar with the resident/nonresident category and the W-4, since correctly setting it up from the first paycheck is far easier than fixing under- or over-withholding later.
Note that a nonresident alien completing Form W-4 as a visa holder generally follows special instructions rather than the standard ones: the IRS’ supplemental notice, Notice 1392, serves this purpose exactly (IRS, Notice 1392). If you have recently arrived in the U.S., changed status, or have had your residency shift partway through the year, it is worth coordinating with your employer’s payroll team to ensure that your withholding is correctly set up from day one.
Social Security and Medicare taxes, together commonly called FICA, are governed by rules of their own, and they do not follow the resident/nonresident distinction as closely as income tax does. Wages paid for services performed in the United States are generally subject to them whether the employee is a resident alien or a nonresident alien, with exceptions tied to particular nonimmigrant categories, most notably F-1, J-1, M-1, and Q-1 status (IRS, Aliens employed in the U.S. – Social Security taxes). For most professionals arriving on an O-1A, these taxes are withheld from the first paycheck alongside federal income tax.
Estimated Taxes for Founders, Consultants, and Equity-Heavy Professionals
The U.S. tax system is pay-as-you-go, meaning that taxes are generally paid as income is earned or received, either through paycheck withholding or estimated tax payments made during the year (IRS, Estimated taxes). For someone with a single salaried job, tax withholding usually handles payment; for many high-skilled arrivals, however, especially founders, taxation is not this straightforward. The IRS notes that estimated payments may apply when withholding is insufficient to cover the year’s total tax bill, or when total income includes income from self-employment, interest, dividends, capital gains, prizes, or awards. This may apply to a founder drawing a small salary while receiving taxable income from equity, a consultant invoicing clients, or an executive with a mix of wages and investment income. Some states even run their own estimated tax systems in addition to the federal one.
Most individual returns are due April 15, although nonresident aliens who received no wages subject to U.S. income tax withholding generally have until June 15 (IRS, Topic no. 851); an extension of time to file is not an extension of time to pay, and interest runs from the original due date (IRS, An extension to file is not an extension to pay taxes). Since underpaying taxes can trigger substantial penalties, this is one area where professional help can really pay off (IRS, Publication 505).
ITIN vs. SSN: Which Tax Identification Number Applies to You
A Social Security Number (SSN) is generally issued to those authorized to work in the United States. An Individual Taxpayer Identification Number (ITIN) is for those with a federal tax filing requirement, but who are not eligible for an SSN. The distinction between these two matters: a work-authorized professional will normally have an SSN, while a spouse or dependent who cannot work may still need an ITIN to be included on a tax return, for example.
The IRS is explicit about the limits of an ITIN (IRS, Individual taxpayer identification number): it is issued for federal tax purposes only. An ITIN does not:
- authorize you to work in the United States
- provide immigration status
- qualify you for Social Security benefits
- serve as identification outside the federal tax system
If you or a family member needs to file taxes or be claimed as a dependent but are not eligible for an SSN, an ITIN will allow that tax filing, but it serves no purpose beyond the federal tax system. An ITIN is requested on Form W-7.
State and Local Taxes
Federal tax is only one layer of the taxation system. As mentioned, many states levy their own income taxes, and some cities and localities also impose their own, with the specific rules varying significantly from place to place. A few states have no personal income tax at all, while others have relatively high taxes. Where you live and work can change what you actually owe.
For anyone who is particularly mobile during their stay in the U.S., this matters greatly. Moving to a new state mid-year, splitting time across states, or running a business from one state while incorporated in another can all introduce tax complications that are easily overlooked. States apply their own residency rules, which are set independently of the federal tests described earlier, so it is possible to be treated as a resident of a state under criteria that have nothing to do with the substantial presence test. Founders especially should keep clear records of where they live, work, and where business activity actually happens. The correct treatment depends on the states involved and should be confirmed by a professional.
On Founder and Executive Tax Complexity
A note for founders and executives: if your income looks more complicated than a single paycheck, assume that the tax side is more complicated too. Common triggers include:
- equity compensation, including stock options and RSUs
- ownership in a foreign company
- foreign bank and financial accounts
- payroll setup for your company
- choices about business entity structure
- tax treaties
- international income from more than one country
Each of these is highly nuanced, dependent on complex factors, and carries real filing consequences. If any of these apply to you, it is a strong indicator that you should work with a qualified tax professional, ideally before your first U.S. filing.
Quick Reference Table
| Topic | Why Important | Where to Read the Official Rules |
| Tax Residency | Determines whether you are taxed as a resident or nonresident | IRS tax residency |
| Scope of Taxable Income | Residents are generally taxed on worldwide income; nonresidents on a narrower set of U.S.-connected income | IRS taxation of U.S. residents / nonresident aliens |
| Substantial Presence | The day-count test that most temporary visa holders encounter | IRS substantial presence test |
| Green Card Timing | The date permanent residence begins, which may be later than the date tax residency began | IRS residency starting and ending dates |
| W-4 | Tells your employer how much tax to withhold; nonresidents follow special instructions | IRS Form W-4 |
| W-2 | Reports your wages and withholding to the IRS | IRS Form W-2 |
| Social Security and Medicare | Generally apply to wages for work performed in the U.S., with exceptions tied to certain nonimmigrant categories | IRS Social Security taxes for aliens |
| Estimated Taxes | May apply when withholding does not cover the year’s total tax | IRS estimated taxes |
| Filing Deadlines | April 15 for most individuals; June 15 for certain nonresidents | IRS filing requirements for aliens |
| ITIN | Federal tax ID when an SSN is not available | IRS ITIN |
| State Taxes | Varies widely by state and locality; states set their own residency rules | Your state’s official tax agency |
Final Thoughts
For many O-1A professionals and future EB-1A applicants, U.S. taxes are less about immigration status and more about understanding how the tax system classifies you. Whether you are a resident or nonresident for tax purposes, how you are paid, where your income comes from, and when your permanent residence begins can all affect your tax obligations.
The good news is that the framework itself is learnable, even where the details are not. Understanding the basics early can help you avoid common mistakes and ask the right questions.
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