Federal tax requirements on OPT hinge on one question: are you still a nonresident alien, or has the calendar turned you into a resident alien for tax purposes? Most F-1 students on OPT are nonresident aliens for their first five calendar years in the United States. That classification means you file Form 1040-NR instead of Form 1040, you pay no Social Security or Medicare tax on your wages, and you may qualify for a treaty benefit that cuts your bill further. Get the classification wrong and everything downstream — the form, the withholding, the FICA, the deductions — goes wrong with it.
Are You a Nonresident Alien or a Resident Alien?
The IRS divides non-citizens into two groups. Resident aliens are taxed on worldwide income and can claim the full standard deduction ($16,100 for single filers in tax year 2026) and most credits available to citizens. Nonresident aliens are taxed only on U.S.-sourced income and face significant restrictions on deductions and credits.
The usual dividing line is the Substantial Presence Test. You meet it if you were physically in the U.S. for at least 31 days in the current year and 183 days over a three-year weighted count: all days this year, one-third of last year’s days, and one-sixth of the days from two years ago.1Internal Revenue Service. Substantial Presence Test
F-1 students get a carve-out. On F, J, M, or Q visas you are an “exempt individual,” and your days in the U.S. do not count toward the test for up to five calendar years. Even a single day in F-1 status during a calendar year burns that whole year off the five.2Internal Revenue Service. Publication 519 (2025), U.S. Tax Guide for Aliens If you arrived in August 2022, your five calendar years are 2022 through 2026.
Once the five years are used up, your days start counting. If you have been continuously in the U.S. on OPT or STEM OPT, you will almost certainly cross the 183-day threshold and become a resident alien. OPT employment itself does not flip your status; only the calendar-year clock does. Nonresidents file Form 1040-NR. Residents file Form 1040.3Internal Revenue Service. Taxation of Nonresident Aliens
No Social Security or Medicare Tax While You’re a Nonresident
F-1 students on OPT who are still nonresident aliens do not owe FICA — Social Security (6.2%) or Medicare (1.45%). That is 7.65% of gross wages you keep that a citizen or resident alien pays. The exemption applies as long as the work is connected to your authorized practical training and you are still within your five calendar years of exempt-individual status. In your sixth calendar year, when you become a resident alien, both you and your employer start paying the standard rates.
Getting Back FICA Your Employer Shouldn’t Have Withheld
Many employers withhold FICA from OPT wages by default. Start with the payroll department: employers can correct the mistake and refund the money directly.
If your employer won’t or can’t help, file Form 843 (Claim for Refund and Request for Abatement) with the IRS, along with Form 8316.4Internal Revenue Service. Form 8316 – Information Regarding Request for Refund of Social Security Tax Erroneously Withheld on Wages Received by a Nonresident Alien on an F, J, or M Type Visa Attach the W-2 showing the withholding, plus copies of your passport, visa, and I-20 or EAD.
There is a hard deadline: three years from the date you filed the original return, or two years from when the tax was paid, whichever is later.5Taxpayer Advocate Service. Refund Statute Expiration Date (RSED) After that window closes, the money is gone.
Tax Treaty Benefits That Can Lower Your Bill
The U.S. has income tax treaties with dozens of countries, and many have provisions specifically for students. Benefits are generally only available while you are still a nonresident alien, though a few treaties reach further. A short sample of commonly used articles:
- China (Article 20): scholarship and fellowship income received by Chinese students is exempt from U.S. tax, and unusually the exemption continues to apply after the student becomes a resident alien.6Internal Revenue Service. Claiming Treaty Exemption for a Scholarship or Fellowship Grant
- India (Article 21): Indian students may claim the standard deduction, which is otherwise unavailable to nonresident aliens. For tax year 2026 that deduction is $16,100 for a single filer.7Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
- South Korea (Article 21): students may exempt up to $2,000 per year in compensation received during training, with a separate provision covering up to $5,000 for compensation while gaining professional experience.8Internal Revenue Service. Tax Treaty Table 2
To claim a treaty benefit on your return, report the specific article and country on Schedule OI of Form 1040-NR.9Internal Revenue Service. Schedule OI (Form 1040-NR) – Other Information If you want your employer to stop withholding on the exempt amount during the year rather than wait for the refund, give them Form 8233. Read IRS Publication 901 and the actual treaty text for your country before you claim anything; the details vary a lot, and a wrong article number on the return will hold up processing.
How the Federal Tax Is Calculated
If you are a nonresident alien, taxable income starts with your U.S.-sourced income, usually the wages on your W-2. Nonresident aliens generally cannot take the standard deduction (India’s treaty is the notable exception). You can claim certain itemized deductions tied to your U.S. income, including state and local income taxes and charitable contributions to U.S. nonprofits, on Schedule A of Form 1040-NR.10Internal Revenue Service. Nonresident — Figuring Your Tax
After treaty exemptions and allowable deductions, the remainder is taxed at the same graduated rates that apply to U.S. citizens. Most OPT workers on entry-level salaries sit in the 10%, 12%, or 22% brackets. For tax year 2026, single filers pay 10% on income up to $12,400, 12% from $12,401 to $50,400, and 22% from $50,401 to $105,700.7Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
That figure gets compared against the federal income tax already withheld by your employer (Box 2 on the W-2). Withheld more than you owe, you get a refund. Withheld less, you pay the difference when you file.
Filling Out Form W-4 as a Nonresident Alien
Getting the W-4 right at the start of the job prevents surprises in April. Nonresident aliens follow the modifications in IRS Notice 1392:11Internal Revenue Service. Notice 1392 – Supplemental Form W-4 Instructions for Nonresident Aliens
- Step 1(c): check “Single or Married filing separately” regardless of your actual marital status.
- Step 2: leave blank unless you hold more than one job at the same time. Do not account for a spouse’s job; nonresident aliens cannot file jointly.
- Step 3: most nonresident aliens leave this blank. Only residents of Canada, Mexico, South Korea, or India may be eligible to claim dependents here.
- Step 4(c): write “nonresident alien” or “NRA” in the space below this line, which triggers your employer to use the correct withholding calculation.
You need a Social Security Number on the W-4; ITINs are not accepted on this form. Most F-1 students on OPT can apply for an SSN through the Social Security Administration with the EAD card and passport.12Internal Revenue Service. Taxpayer Identification Numbers (TINs) for Foreign Students and Scholars
What to File, and When
Every F-1 student in the U.S. during the tax year, OPT included, must file Form 8843, even with zero income. The form documents your exempt-individual status and keeps those days out of the Substantial Presence Test in future years.13Internal Revenue Service. About Form 8843, Statement for Exempt Individuals and Individuals with a Medical Condition Skip it and the IRS can inadvertently treat you as a resident alien later, which changes how all your income is taxed.
If you earned U.S.-sourced income, you also file Form 1040-NR (assuming you are a nonresident alien). The deadline depends on your income type:
- April 15 if you received wages subject to U.S. income tax withholding during the year.14Internal Revenue Service. Instructions for Form 1040-NR (2025)
- June 15 if you did not.
Attach Form 8843 to your 1040-NR. If Form 8843 is your only filing requirement, mail it separately to the IRS Service Center in Austin, TX 73301-0215 by the applicable deadline.15Internal Revenue Service. Form 8843 – Statement for Exempt Individuals and Individuals With a Medical Condition
Form 1040-NR can be filed electronically, and e-filing is faster.14Internal Revenue Service. Instructions for Form 1040-NR (2025) One important boundary: mainstream tax software like TurboTax is built for Form 1040 and does not properly handle Form 1040-NR. Nonresidents need software designed for nonresident returns or should prepare the return manually.
Before you sit down to file, gather your W-2s, any Form 1042-S (which reports treaty-exempt or scholarship income), your passport, visa, I-20, and EAD. If you are claiming a treaty benefit, have the exact article number in front of you. Keep copies of everything.
The Year You Switch to Resident Status
Some OPT workers cross from nonresident to resident partway through a single tax year, most often when the five-year clock runs out or they switch to H-1B. That produces a dual-status tax year: part taxed under nonresident rules, part under resident rules.16Internal Revenue Service. Taxation of Dual-Status Individuals
Dual-status returns are restrictive. You cannot take the standard deduction, cannot use head-of-household filing status, and cannot claim credits like the earned income credit, unless you elect to be taxed as a full-year resident jointly with a U.S. citizen or resident spouse. You can itemize allowable deductions for the resident portion. The mechanics are in Publication 519, and if your transition year involves significant income on both sides of the line, this is a return worth handing to a professional.
State Taxes Are Separate — and Treaties Usually Don’t Apply
Federal is only half the picture. Most states impose their own income tax, and if you work in one you’ll almost certainly owe state tax on your wages regardless of your federal status.
The trap: federal income tax treaties generally do not apply to state taxes. Some states voluntarily honor them, but many do not. California, New Jersey, and Pennsylvania explicitly disallow treaty exemptions for state income tax purposes.17Internal Revenue Service. IRS Courseware – State Income Taxes If you claimed a treaty benefit that lowered your federal taxable income, your state may make you add it back. Check with your state’s tax department for the rule and the return.
Penalties for Filing Late or Not at All
Owing tax and filing late triggers a failure-to-file penalty of 5% of the unpaid tax per month, up to 25%.18Internal Revenue Service. Failure to File Penalty A separate failure-to-pay penalty of 0.5% per month applies if you don’t pay by the due date. Both can run at the same time, though the failure-to-file penalty is reduced by the failure-to-pay amount in any month both apply.
Skipping Form 8843 is a different kind of risk. Without it, your days of presence aren’t excluded from the Substantial Presence Test, and the IRS can reclassify you as a resident alien. That reclassification changes which form you should have filed, which deductions you could have taken, and whether you owed FICA, and it can produce a chain of errors that is expensive to fix.
Filing history also follows you into immigration. The IRS and USCIS are separate agencies, but visa applications and green card petitions routinely ask about tax filings. Gaps and inconsistencies in your record can create problems well beyond the penalty amount itself.