Social Security and Medicare: Who Pays and When It Starts

Look at a pay stub and two lines sit beside federal income tax: Social Security and Medicare, together called FICA. Many students on OPT see nothing on those lines, and many H-1B workers wonder whether they will ever see a benefit from what is taken. This chapter explains who pays, why the student exemption exists and exactly when it ends, what to do if it was withheld by mistake, and what the payments are worth if you later leave the US.

What FICA is and what it costs

FICA is the federal payroll tax that funds Social Security (retirement, disability and survivor benefits) and Medicare (health insurance from 65). For an employee in 2026 it has three parts:

• Social Security tax of 6.2% on wages up to $184,500 in the year;
• Medicare tax of 1.45% on all wages;
• Additional Medicare Tax of 0.9% on wages above $200,000, which an employer withholds above that amount whatever your filing status.

Your employer pays a matching share on top. Together the two employee rates come to 7.65% of most paychecks, which is why the exemption described below is worth real money:

For a salary on which the employee's 7.65% comes to $459 a month, FICA adds up to $5,508 a year and $16,524 over 3 years. For a student who is exempt, that money stays in the paycheck. For anyone else it is withheld whether or not they ever claim a benefit.

Who pays: the work visas

Publication 519 is direct: Social Security and Medicare taxes apply to wages for work performed as an employee in the US regardless of the citizenship or residence of the employee or the employer, and the employer must withhold them even if you do not expect to qualify for benefits.

So H-1B, L-1, O-1, E-3, TN and similar workers pay FICA from the first paycheck, including in a first year when they are nonresident aliens for income tax. A spouse with work authorization in H-4 or J-2 status also pays: Publication 519 says the student exemption does not reach F-2, J-2, M-2 or Q-3 family members. Being a nonresident for income tax does not, by itself, exempt anyone from FICA.

The one route out for some work-visa holders is a totalization agreement, covered below.

Who does not pay: students and exchange visitors

Publication 519 exempts the pay of a nonresident alien in F, J, M or Q status for work done to carry out the purpose of the visa. In practice that covers:

• on-campus work, including teaching and research assistantships;
• practical training: curricular practical training (CPT) and optional practical training (OPT), including the STEM extension;
• off-campus work allowed for severe economic hardship;
• for J-1 exchange visitors, work the sponsor has authorized in writing.

Two conditions do the work, and both must hold.

You must still be a nonresident alien. The moment you become a resident alien under the substantial presence test, FICA applies, even though you still hold the same F or J visa. For an F-1 student that is usually January 1 of the sixth calendar year in the US (chapter 2). For a J-1 researcher or teacher it is usually the third calendar year. OPT that runs into your sixth calendar year is therefore subject to FICA from your residency starting date that year, which is January 1 if you are in the US that day.

The work must belong to your status. Work outside what your status allows is not covered by the exemption. When a student changes status, for example from F-1 to H-1B, FICA applies to the pay earned in the new status.

Payroll systems get this wrong in both directions: some withhold from an exempt student, and some keep exempting a student who has become a resident. Check your status each January and your first pay stub after any change.

If it was withheld by mistake

If FICA was withheld from pay that was exempt, Publication 519 sets out two steps:

1. Ask your employer first. The employer can refund the amount and correct its own filings.
2. If the employer will not refund it all, file Form 843 with the IRS. Attach a copy of your Form W-2, your visa, your I-94, your I-20 (F-1) or DS-2019 (J-1), your EAD card (Form I-766) if you were on OPT, and a statement from your employer about any refund it gave. If the employer will not provide that statement, explain why, or attach Form 8316.

Claims for a refund have time limits, so do not leave it for years. Additional Medicare Tax withheld in error is claimed differently, on your income tax return.

What you get for the tax: credits and benefits

A US retirement benefit needs 40 credits. In 2026 you earn one credit for each $1,890 of covered earnings, and at most four credits in a year, so qualifying takes at least ten years of covered work. Someone who works in the US for five or six years and leaves usually has no US retirement benefit from that work on its own, and the tax is not refunded when they go. That is the honest cost to weigh.

Two things can change it.

Totalization agreements. The US has Social Security agreements with 31 countries, including Canada, the United Kingdom, Germany, Japan, South Korea, Australia and Brazil. India and China are not on the list as of September 2026. An agreement does two things:

• it stops double payroll tax: a worker temporarily sent to the US by an employer from an agreement country can usually stay in the home system and be exempt from US FICA, with a certificate of coverage from the home country's agency, which matters most for L-1 transferees;
• it lets the Social Security Administration add your home-country coverage to your US credits to reach the 40, provided you have at least 6 US credits. The benefit is then a partial one, based on the share of your career worked in the US.

Medicare. Medicare tax pays for Medicare, which you can use only if you are in the US and eligible. If you leave, it is a cost, not a saving.

The Social Security for visa holders calculator shows what your years of US work could be worth and whether your country has an agreement.