You got the STEM OPT extension. Twenty-four more months in the US, staying at the job you worked hard to get. But now tax season is coming and something feels different: your colleagues are asking if you've "gone resident" yet, your payroll person mentioned FICA, and you're not sure if Sprintax still applies to you. It might. It might not. This guide explains exactly what changes when STEM OPT begins and when it doesn't.
Quick answer: During STEM OPT, most of the tax rules are the same as standard OPT: you likely still file Form 1040-NR, still use Sprintax, and are still exempt from FICA. The one thing that can change is your tax residency status. If you've been in the US for more than 5 full calendar years on an F visa and you meet the Substantial Presence Test in a given year, you flip to resident alien status, meaning Form 1040, FICA withholding, and standard deduction eligibility. Whether you've crossed that threshold is the core question this guide helps you answer.
What You Need to Know First
Two separate systems determine your tax obligations as a STEM OPT student:
1. IRS tax residency: Are you a non-resident alien (NRA) or resident alien (RA) for federal tax purposes? This determines which form you file and what rules apply.
2. USCIS immigration status: You remain an F-1 student on OPT throughout your STEM extension. This never changes from a visa perspective.
These two systems operate independently. Your immigration status doesn't automatically determine your tax residency. A STEM OPT student can be either an NRA or an RA for tax purposes depending on how long they've been in the US.
The 5-year exemption: F-1 students are exempt from the Substantial Presence Test (SPT) for their first 5 calendar years in the US. During this period, regardless of how many days you're physically present, you're classified as an NRA for tax purposes.
After 5 calendar years, the exemption expires. You start counting days under the SPT formula. If you meet the 183-day threshold (using the weighted 3-year formula), you become a resident alien for that tax year.
⚠️ As of 2026: verify annually: Tax residency rules are subject to IRS interpretation and regulatory updates. Confirm your specific situation at IRS.gov or with a tax professional before filing. This guide reflects rules current as of the 2025 tax year.
Has Your Tax Residency Status Changed?
This is the first question to answer before you touch any tax software. Here's how to work through it:
Step 1: Count your calendar years on F status in the US. Count each calendar year (January 1–December 31) in which you were physically present in the US on an F-1 or F-2 visa, even one day in a year counts as a full calendar year for this purpose.
Step 2: Have you exceeded 5 calendar years?
- If no (you arrived in 2022 or later, or your calendar year count is 5 or fewer): you are still an NRA. File Form 1040-NR. Nothing changes from standard OPT.
- If yes (you've been in the US on F status since 2020 or earlier): continue to Step 3.
Step 3: Apply the Substantial Presence Test for the current year. Count your US days for the current year plus 1/3 of last year's days plus 1/6 of the year before that. If the total is 183 or more, you are a resident alien for this tax year.
Step 4: Check the "closer connection" exception. Even if you meet the SPT, you may qualify as an NRA if you can demonstrate a closer connection to a foreign country (Form 8840). This is complex: consult a tax professional if you're near the 183-day threshold and want to maintain NRA status.
Sprintax runs this calculation automatically when you input your visa dates and entry history. If you're in year 6+ of F status, be especially careful to enter your dates accurately.
When You're Still an NRA on STEM OPT: What Stays the Same
If you haven't crossed the 5-year exemption threshold, STEM OPT tax filing is essentially identical to standard OPT:
Form 1040-NR: still your federal tax return. Use Sprintax or Glacier Tax Prep.
Form 8843: still required every year, even on STEM OPT. Read our guide on how to file taxes on OPT as an F-1 student.
FICA exemption: still applies. Social Security and Medicare are still not deducted from your paycheck while you're an NRA. Check your pay stubs when your STEM OPT begins: some payroll systems reset when your EAD is renewed and accidentally turn FICA on.
No standard deduction: NRAs generally cannot take the standard deduction. This doesn't change with STEM OPT.
Tax treaty benefits: if you were claiming a treaty benefit (e.g., China's $5,000 student exemption under Article 20), check whether your treaty clause still applies on STEM OPT. Many student-specific treaty clauses cover "students and trainees", which STEM OPT typically qualifies as, but verify with your specific treaty text or a tax advisor.
Sprintax remains the right software. Nothing about the STEM extension changes which tax software you should use while you're still an NRA.
When You Become a Resident Alien on STEM OPT: What Changes
If you've crossed the 5-year threshold and meet the SPT for the current tax year, you're now a resident alien for IRS purposes. This changes several things:
You Now File Form 1040 (Not 1040-NR)
Form 1040 is the standard US tax return. You can now use TurboTax, H&R Block, FreeTaxUSA, or any mainstream tax software. Sprintax is no longer required (though Glacier can still file 1040 in some configurations).
You now get the standard deduction. For tax year 2025, the standard deduction for single filers is $14,600. This is a significant benefit: as an NRA you weren't entitled to this, so your taxable income may actually decrease even though you're now classified as a resident.
You can now contribute to tax-advantaged accounts like a Roth IRA, 401(k), and HSA, all of which were technically available before but carry more benefit for resident filers planning longer US stays. Read our guide on if international students can open a Roth IRA on OPT.
FICA Taxes Now Apply
This is the biggest practical change. As a resident alien, you are no longer exempt from FICA. Your employer should now withhold:
- Social Security: 6.2% of wages (up to the annual wage base)
- Medicare: 1.45% of wages (no cap)
If your STEM OPT began mid-year and you cross the SPT threshold during that year, your FICA exemption ends at the point you become a resident. Practically, payroll systems often don't handle this mid-year transition automatically: you may need to notify HR of your changed status.
Expect your take-home pay to decrease when FICA kicks in. On a $90,000 STEM OPT salary, FICA is approximately $6,885/year, roughly $574/month less in take-home pay than you had as an NRA.
You May File Jointly if Married
As a resident alien, you can elect to file jointly with a spouse who is also a resident or US citizen. As an NRA, joint filing was generally not available. This is only relevant if you're married to another F-1/OPT student or a US citizen.
Form 8843 Is No Longer Required
Once you're a resident alien, Form 8843 is no longer part of your return. You're no longer claiming the SPT exemption because you're no longer exempt, you're now taxed as a resident.
The Dual-Status Return: When You Change Status Mid-Year
If you crossed the NRA-to-resident threshold partway through a tax year, for example, you became a resident alien on July 15, you file a dual-status return for that year.
A dual-status return covers two periods:
- NRA period: Form 1040-NR for the portion of the year before you became a resident
- Resident period: Form 1040 for the portion after
This is the most complex return F-1 students ever face. Sprintax handles dual-status returns and will guide you through the process if your dates put you in mid-year transition. If your situation feels complex, a tax professional who specializes in NRA returns is worth the consultation fee: usually $100–$250 for a simple dual-status return.
Key Differences: NRA vs Resident Alien on STEM OPT
| Tax Rule | NRA (Standard + STEM OPT, years 1–5) | Resident Alien (STEM OPT, years 6+) |
|---|---|---|
| Tax form | Form 1040-NR | Form 1040 |
| Software | Sprintax / Glacier | TurboTax / any mainstream |
| Standard deduction | ❌ No | ✅ $14,600 (2025) |
| FICA taxes | ❌ Exempt | ✅ 7.65% withheld |
| Form 8843 | ✅ Required | ❌ Not required |
| Joint filing | ❌ Generally not | ✅ If married |
| Roth IRA eligibility | ✅ Technically yes | ✅ Yes |
| Tax treaty benefits | ✅ If applicable | ⚠️ Limited |
| State taxes | Same rules | Same rules |
Real Student Scenarios
Priya's situation: Priya arrived in August 2021 (calendar year 1). Her 5th calendar year is 2025. She started STEM OPT in March 2025. Because she's still within her 5 exempt calendar years, she files Form 1040-NR for the 2025 tax year: same as before. Her STEM OPT changes nothing about her tax filing in 2025. She'll revisit this calculation in 2026.
Wei's situation: Wei arrived in January 2019 (calendar year 1). His 5th calendar year ended December 31, 2023. In 2024, his first year of STEM OPT, he was present in the US for 340 days. Under the SPT: 340 + (120 × 1/3) + (110 × 1/6) = 340 + 40 + 18 = 398 days, well over 183. Wei is a resident alien for 2024. He files Form 1040 using TurboTax, gets the $14,600 standard deduction, and pays FICA for the first time. His effective tax rate drops slightly because the standard deduction offsets his income.
Sanjay's situation: Sanjay arrived in August 2020 (calendar year 1). By 2025, he's in his 6th calendar year. He runs the SPT for 2025: 310 + (290 × 1/3) + (340 × 1/6) = 310 + 97 + 57 = 464 days. Resident alien. But Sanjay traveled internationally for 3 months in 2025 for a research conference: those days outside the US don't count toward the SPT. His corrected SPT calculation is still well over 183. He files Form 1040. His employer begins FICA withholding from January 2026 onward.
Common Mistakes to Avoid
1. Assuming STEM OPT automatically changes your tax status. Fix: STEM OPT itself doesn't change anything. What matters is whether you've exceeded 5 calendar years on F status and meet the SPT. Calculate before assuming.
2. Not checking your FICA withholding when STEM OPT paperwork is processed. Fix: Review your first pay stub after your EAD renewal. Some payroll systems reset to default FICA withholding when EAD numbers change. If you're still an NRA, correct it immediately.
3. Filing Form 1040 as an NRA because "STEM OPT is more like a resident." Fix: Tax residency is determined by years and day counts, not visa category or how long you've been working. Sprintax calculates it correctly. Don't guess.
4. Not consulting a tax professional for your first dual-status year. Fix: Dual-status returns are genuinely complex. A one-time $100–$250 consultation fee is worth getting it right. Your university's international tax advisor may do this for free.
5. Forgetting Form 8843 in your last NRA year. Fix: Even if it's your final year as an NRA, you still need to file Form 8843 for that year. It's your last one, and it still matters.
Bottom Line
When STEM OPT begins, run your calendar year count immediately. If you arrived in 2021 or later, you're almost certainly still an NRA: file 1040-NR with Sprintax, same as before. If you arrived in 2019 or 2020, run the Substantial Presence Test carefully for each year: you may have already crossed into resident alien status, which means Form 1040, FICA, and the standard deduction.
The transition isn't painful, resident alien filing is actually simpler in many ways. The key is knowing which side of the line you're on before you file, not after the IRS sends you a notice.
The moment students cross into resident alien status is often a financial positive: they get the standard deduction and can contribute to a Roth IRA with full benefits. The FICA hit hurts in the short term, but the overall tax picture is often more favorable than expected. The mistake is not knowing it happened.
FAQ
Q: Does starting STEM OPT change my tax residency status? A: Not automatically. Your tax residency depends on how many calendar years you've been in the US on F status and whether you meet the Substantial Presence Test. Starting STEM OPT doesn't itself trigger a residency change.
Q: Am I still exempt from FICA taxes on STEM OPT? A: Only if you're still a non-resident alien. If you've crossed the 5-year exemption threshold and meet the Substantial Presence Test, you're now a resident alien and FICA taxes apply. Check your residency status each tax year.
Q: Should I use Sprintax for STEM OPT taxes? A: If you're still a non-resident alien, yes, Sprintax is the right tool. If you've become a resident alien, you can use any mainstream software including TurboTax. Sprintax will determine your status automatically when you enter your visa and entry date information.
Q: What is a dual-status tax return and do STEM OPT students need to file one? A: A dual-status return covers a year in which you were both an NRA and a resident alien, for example, if you crossed the Substantial Presence Test threshold on August 1st. You file Form 1040-NR for the first portion of the year and Form 1040 for the second. Sprintax handles dual-status returns. This typically applies in the first year you cross the residency threshold.
Q: Can I claim a tax treaty benefit as a resident alien on STEM OPT? Tax treaty benefits for non-resident aliens generally don't apply once you become a resident alien: most treaties have a saving clause that limits benefits for residents. The China $5,000 student exemption, for example, is generally only available to NRAs. Confirm the specifics of your country's treaty with a tax professional.
