A nonresident alien employee can have several U.S. tax rules operating on the same paycheck. Federal income tax withholding, Social Security and Medicare taxes, and state or local withholding are separate systems. A rule that changes one of them does not automatically change the others.
The starting point is federal tax residency, not simply the immigration label shown on a visa. From there, the tax treatment can depend on where the work was physically performed, whether the compensation is employee wages, whether an income tax treaty applies, the employee’s nonimmigrant classification, and the documentation held by the employer.
Nonresident alien does not mean tax-exempt employee. An NRA employee may have federal income tax withheld and may also be subject to Social Security and Medicare taxes unless a separate exemption applies.
A Paycheck Can Contain Three Different Tax Layers
Payroll deductions can be easier to understand when federal income tax, FICA, and state tax are treated as separate questions rather than one combined “nonresident tax.”
| Tax Layer | Main Question | What Can Affect the Result |
|---|---|---|
| Federal income tax | How are the employee’s wages taxed and withheld? | Tax residency, U.S.-source wages, treaty provisions, Form W-4, and special NRA withholding rules |
| Social Security and Medicare | Are the wages covered by FICA? | Tax residency, nonimmigrant status, type of authorized employment, and possible Totalization Agreement coverage |
| State and local tax | Does the applicable state or locality tax the wages? | Work location, state residency rules, state sourcing rules, and the state’s treatment of treaty-exempt income |
For example, a treaty may reduce federal income tax on certain wages while Social Security and Medicare taxes remain fully applicable. In another case, an F-1 student who remains a nonresident alien may have federal income tax withheld while qualifying employment is exempt from FICA. State tax can produce yet another result.
Tax Residency Changes Which Employee Rules Apply
Immigration status and federal tax residency are related, but they are not the same classification. An individual who is temporarily in the United States can be a resident alien for federal tax purposes, while another person who has spent several years in the country may still be a nonresident alien because certain days do not count toward the Substantial Presence Test.
Federal resident-alien status is generally determined through the Green Card Test or the Substantial Presence Test. Certain individuals temporarily present in F, J, M, or Q classifications may be treated as “exempt individuals” for purposes of the Substantial Presence Test. In this context, exempt individual means that qualifying days of physical presence are excluded from the residency calculation. It does not mean that the person’s wages are automatically exempt from U.S. tax.
The permitted period for excluding days differs by category and prior U.S. history. Students and nonstudent teachers or trainees do not use the same calendar-year rules. Previous periods in F, J, M, or Q status can also affect the calculation.
This makes tax residency a year-by-year issue. An employee can keep the same job and salary but move from nonresident-alien treatment to resident-alien treatment in a later tax year. That change can alter withholding instructions and can also end some visa-based FICA exemptions.
Work Location Determines Where Employee Wages Are Sourced
Compensation for personal services is generally sourced according to where the services are physically performed. The location of the employer, the bank receiving the paycheck, or the employee’s citizenship does not by itself determine the source of employee compensation.
Wages for services performed in the United States are generally U.S.-source compensation. Wages attributable to services performed outside the United States are generally foreign-source compensation, subject to the applicable sourcing rules and exceptions.
When an employee performs services both inside and outside the United States, compensation may need to be allocated between U.S. and foreign sources. For ordinary employee compensation, a time-based allocation is commonly used unless another permitted method more accurately reflects the source. Certain fringe benefits have separate sourcing rules.
This distinction matters because nonresident aliens are generally taxed by the United States on U.S.-source income and on income that is effectively connected with a U.S. trade or business, while foreign-source income is generally outside the normal U.S. income tax base for an NRA unless a specific rule brings it within U.S. taxation.
Employee Wages Usually Do Not Use the Flat 30% NRA Withholding Rule
The statutory 30% withholding rate associated with some payments to foreign persons is not a universal tax rate for nonresident aliens.
Employee wages for dependent personal services are generally subject to graduated wage withholding when the wages are effectively connected with the conduct of a U.S. trade or business. IRS Publication 515 specifically distinguishes these wages from payments that use the 30% withholding system.
The 30% rate is not the default withholding rate for ordinary NRA employee wages. Regular employee compensation and many nonemployee payments follow different withholding rules.
This also makes worker classification relevant. Compensation paid within an employer-employee relationship is treated differently from compensation for independent personal services. Calling a worker a contractor does not by itself determine the federal tax classification; the actual working relationship matters.
Why Federal Withholding Can Look Higher Than Expected
A nonresident alien employee whose wages are subject to federal income tax withholding generally provides Form W-4, but the ordinary Form W-4 instructions are not the only rules involved. The IRS provides supplemental instructions for NRAs in Notice 1392, and employers use a modified calculation described in Publication 15-T.
Under that calculation, the employer may add a specified amount to the employee’s wages only for the purpose of calculating federal income tax withholding. The amount varies with the payroll period and the version of Form W-4 involved.
The payroll adjustment is not additional salary. It is not added to the employee’s Form W-2 wages, does not by itself increase federal taxable income, and does not increase wages for Social Security, Medicare, or federal unemployment tax purposes.
That distinction explains why the federal income tax withheld from an NRA paycheck can appear higher than expected when someone simply compares gross pay with the standard withholding tables used for many U.S. employees.
For 2026, Publication 15-T continues to use this special NRA withholding adjustment. Nonresident alien students from India and business apprentices from India are excluded from the added-wage procedure described there.
Tax Treaties Can Change Income Tax Without Removing FICA
A U.S. income tax treaty may exempt some employee compensation from federal income tax or limit the amount that can be taxed, but treaty treatment is not based on citizenship alone. The applicable treaty article can impose requirements involving treaty-country residence, the type of work, the employee’s purpose for being in the United States, the length of the visit, the employer, or a maximum amount of compensation.
For dependent personal services, Form 8233 is used when a nonresident alien claims a treaty withholding exemption for part or all of the compensation. Form W-4 is generally used for the portion of employee compensation for which no treaty withholding exemption is claimed.
A federal income tax treaty exemption does not automatically create an exemption from Social Security and Medicare taxes. FICA is tested under separate rules. An employee can therefore have treaty-exempt federal wages while remaining subject to Social Security and Medicare taxes.
Social Security and Medicare Use a Separate Test
The general federal rule is that wages paid to nonresident aliens for employee services performed in the United States are subject to Social Security and Medicare taxes. Specific statutory exemptions can change that result.
| Employee Situation | General FICA Treatment | What Must Be Examined |
|---|---|---|
| F-1, J-1, or M-1 student who remains an NRA | A visa-based FICA exemption may apply | The work must be authorized and performed to carry out the purpose of the status |
| J-1 or Q-1 nonstudent who remains an NRA | A visa-based FICA exemption may apply | Status, tax residency, authorized employment, and connection between the services and the program purpose |
| H-1B employee | Generally subject to FICA | A Totalization Agreement or another statutory exception may alter coverage |
| O-1 or TN employee | Generally subject to FICA | A Totalization Agreement or another applicable exception may alter coverage |
| F-2, J-2, or M-2 dependent with employment authorization | No automatic visa-based FICA exemption from the principal holder’s status | Any separate FICA exception applicable to the employment |
F-1, J-1, and M-1 Students
Foreign students in F-1, J-1, or M-1 status who remain nonresident aliens can be exempt from Social Security and Medicare taxes on qualifying U.S. wages. The employment must be permitted under the applicable immigration rules and must be connected with the purpose for which the status was granted.
Qualifying employment can include authorized on-campus work and practical training. Employment that is unauthorized or not sufficiently connected to the purpose of the status does not receive the visa-based exemption. The exemption also generally ends when the individual becomes a resident alien for federal tax purposes or changes to a status that does not carry the exemption.
A separate student FICA exception can sometimes apply to students employed by the school, college, or university where they are enrolled. That rule is distinct from the F-1, J-1, or M-1 exemption and has its own conditions.
J-1 and Q-1 Teachers, Researchers, Trainees, and Other Participants
J-1 and Q-1 nonstudent employees who remain nonresident aliens can also fall within the special FICA exception when their services are authorized and performed to carry out the purpose for which the status was granted. This can cover categories such as teachers, researchers, professors, trainees, and certain other exchange-program participants.
The tax-residency analysis still matters. The calendar-year rules for excluding presence as a teacher or trainee differ from the student rules, and prior periods in exempt-individual status can change the result.
H-1B, O-1, and TN Employees
H-1B employees are generally subject to Social Security and Medicare taxes from the effective date of H-1B employment even if they are still classified as nonresident aliens for federal income tax purposes. The same general FICA treatment applies to employees working in O-1 or TN status.
This produces a situation that can initially appear inconsistent: an employee may still be an NRA for income tax purposes while paying Social Security and Medicare taxes like other covered employees. Tax residency and FICA coverage are separate determinations.
A U.S. Social Security Totalization Agreement can affect which country’s social security system covers an employee in certain cross-border employment situations. Where an agreement applies, coverage is determined under the terms of that agreement rather than simply by visa category.
What the 2026 FICA Amounts Mean on a Paycheck
The annual FICA rates matter only after determining that the employee’s wages are covered by Social Security and Medicare. For covered wages in 2026, the employee-side amounts are:
| Payroll Tax | 2026 Employee Rate | 2026 Wage Limit or Threshold |
|---|---|---|
| Social Security | 6.2% | Applies to covered wages up to $184,500 |
| Medicare | 1.45% | No wage base limit |
| Additional Medicare Tax withholding | 0.9% in addition to regular Medicare withholding | Employer withholding begins after Medicare wages paid by that employer exceed $200,000 during the calendar year |
The $200,000 Additional Medicare Tax figure is an employer withholding threshold. The employee’s final Additional Medicare Tax liability is determined under separate rules that can depend on filing status and total applicable wages or compensation, so the amount withheld by one employer is not necessarily the final tax amount.
Why W-2 and 1042-S Can Both Appear for the Same Job
Year-end tax documents reflect how different portions of compensation were treated. Ordinary employee wages subject to graduated wage withholding are generally reported on Form W-2.
If an employee submits Form 8233 and a qualifying treaty exemption applies to employee compensation, Publication 515 provides that the treaty-exempt wages are reported on Form 1042-S rather than in box 1 of Form W-2. Treaty-exempt federal wages can still appear in state or local wage boxes on Form W-2 when state or local tax law treats those wages as taxable.
An employee can therefore receive both forms from the same employer. One form may report the taxable wage portion while the other reports compensation receiving treaty treatment.
During employment: Form W-4 generally supports regular wage withholding; Form 8233 can be used for a qualifying treaty withholding exemption.
After the year ends: Form W-2 can report taxable wages, Form 1042-S can report treaty-exempt compensation, and some employees can receive both.
Federal return stage: When a Form 1040-NR filing requirement applies, the return reconciles reportable income, treaty treatment where applicable, federal tax liability, and tax already withheld.
Withholding Is a Prepayment, Not the Final Federal Tax
The federal income tax shown as withheld on a paycheck or year-end tax form is not automatically the employee’s final income tax liability. Payroll withholding is an amount paid toward the tax calculation.
The final federal result can depend on taxable income, treaty treatment, deductions or credits permitted under the applicable NRA rules, and amounts already withheld. Where a federal return is required, those items are reconciled on the return. Excess withholding can result in a refund, while insufficient withholding can leave additional tax due.
This is also why the special amount that an employer adds to wages under the NRA withholding calculation should not be mistaken for taxable income. It changes the payroll calculation but is not itself additional compensation reported to the employee.
Federal Treatment Does Not Set the State Result
Federal nonresident-alien status does not establish state tax residency. States use their own residency, domicile, and income-sourcing rules, and an individual can be treated differently for state and federal purposes.
States also do not all treat federal income tax treaty provisions the same way. Compensation that is exempt from federal income tax under a treaty can remain taxable by a state. Work performed in more than one state can add another sourcing question.
For that reason, a federal treaty exemption, federal FICA exemption, and state wage exemption should not be treated as interchangeable concepts.
How the Rules Combine in Typical Employee Situations
F-1 Student Working on OPT
Consider an F-1 student performing authorized Optional Practical Training in the United States while remaining a nonresident alien for federal tax purposes. The wages are employee compensation for U.S. services, so federal income tax withholding can apply. If the employment meets the conditions for the F-1 visa-based FICA exception, Social Security and Medicare taxes can be treated differently from the federal income tax withholding on the same wages.
The employee would ordinarily receive a Form W-2 for taxable employee wages unless a qualifying treaty provision changes the treatment of part of the compensation.
J-1 Researcher With Treaty-Exempt Compensation
A J-1 researcher who remains an NRA may have more than one special rule operating at once. Qualifying J-1 employment can fall within the visa-based FICA exemption, while an applicable income tax treaty may separately exempt some compensation from federal income tax.
If a valid treaty withholding position applies through Form 8233, the treaty-exempt compensation can be reported on Form 1042-S. Any remaining taxable employee wages can appear on Form W-2. Neither result by itself determines whether a state will tax the same compensation.
Employee Changing From F-1 to H-1B
A change from F-1 to H-1B illustrates why immigration classification and tax residency have to be separated. An employee can still be a nonresident alien under the federal residency tests during the year of the change, depending on the relevant days of presence and prior history.
The F-1 visa-based FICA exemption, however, generally stops when H-1B status becomes effective. Social Security and Medicare withholding can therefore begin even though the employee’s federal income tax residency has not yet changed to resident alien. A Totalization Agreement can produce a different FICA result in an applicable cross-border case.
Paycheck and Tax Form Mismatches Worth Reviewing
Some payroll differences are expected because the systems do not use identical rules. Others can indicate that the employer’s records, tax residency information, or treaty documentation need to be reviewed.
Social Security and Medicare appear on wages that may meet an F-1, J-1, or M-1 exemption. The relevant questions include whether the employee was still an NRA, whether the work was authorized, and whether the services were connected with the purpose of the status. The IRS describes requesting a refund from the employer first when FICA was withheld in error. Where the employer does not provide the refund, the IRS has a separate refund procedure involving Form 843 and, for qualifying foreign students, Form 8316.
Payroll still applies NRA withholding after federal tax residency changes. Because tax residency can change from one calendar year to another, payroll information that was correct in an earlier year may no longer reflect the employee’s current federal tax status.
A treaty benefit was expected but the entire wage amount appears on Form W-2. Treaty benefits are not automatic solely because an employee comes from a treaty country. The specific treaty provision, eligibility conditions, and withholding documentation determine whether payroll can apply an exemption.
Both Form W-2 and Form 1042-S were issued. Receiving both is not inherently an error. It can reflect taxable wages and treaty-exempt compensation from the same employment relationship.
The federal and state wage amounts are different. Treaty-exempt wages that are excluded from federal Form W-2 box 1 can still be reportable for state or local purposes. State residency and sourcing rules can create additional differences.
Resources Used
- IRS Publication 515, Withholding of Tax on Nonresident Aliens and Foreign Entities — rules for NRA employee wages, graduated withholding, Form W-4, treaty withholding, Form W-2, and Form 1042-S.
- IRS Publication 15-T, Federal Income Tax Withholding Methods — 2026 special withholding calculation for nonresident alien employees.
- IRS Notice 1392, Supplemental Form W-4 Instructions for Nonresident Aliens — supplemental Form W-4 rules for NRA employees.
- IRS Instructions for Form 8233 — treaty withholding rules for dependent personal services and other qualifying compensation.
- IRS Foreign Student Liability for Social Security and Medicare Taxes — F-1, J-1, and M-1 student FICA rules and qualifying employment conditions.
- IRS FICA Rules for Foreign Teachers, Researchers, and Other Professionals — J-1, Q-1, H-1B, O-1, TN, dependent, and Totalization Agreement treatment.
- IRS Publication 15, Employer’s Tax Guide — 2026 Social Security, Medicare, and Additional Medicare Tax withholding amounts.
- IRS Publication 519, U.S. Tax Guide for Aliens — federal alien residency, income sourcing, treaty, and nonresident-alien tax rules.