The difference between FICA and Social Security tax is that FICA isn’t a separate tax at all. The Federal Insurance Contributions Act is the law that requires two payroll taxes to be withheld from your paycheck: one for Social Security at 6.2% of wages, and one for Medicare at 1.45%. When people say “FICA tax,” they mean both of those pieces together. When they say “Social Security tax,” they mean only the larger of the two.
FICA Is the Container, Social Security Tax Is One Piece Inside It
The Federal Insurance Contributions Act sits in Chapter 21 of the Internal Revenue Code and is the legal authority behind payroll withholding for both Social Security and Medicare. It isn’t a single tax. It’s a framework that pulls two separate contributions out of every paycheck.
You can see this on your pay stub. There are usually two line items: one for Social Security, sometimes labeled OASDI, and one for Medicare, sometimes labeled HI. Add them and you have your total FICA withholding. Your employer pays the same amounts on top of what you paid, doubling the money going into both programs.
The Social Security Piece
The Social Security portion of FICA is formally called Old-Age, Survivors, and Disability Insurance. It funds monthly payments to retirees, workers with qualifying disabilities, and the surviving spouses and children of deceased workers who paid into the system. The IRS collects the money and deposits it into two federal trust funds, one for retirement and survivors benefits and one for disability. Current workers fund the benefits of current retirees, so the system runs on an ongoing stream of contributions.
For 2026, the rate is 6.2% of your wages, up to a maximum taxable earnings cap of $184,500. Once your year-to-date earnings cross that line, the 6.2% withholding stops for the rest of the calendar year. Anything you earn above the cap is free of Social Security tax. Medicare, as you’ll see next, doesn’t work that way.
The Medicare Piece
The other piece of FICA funds Hospital Insurance, better known as Medicare Part A. That program covers inpatient hospital stays, skilled nursing care, and hospice for people aged 65 and older, along with younger people who have certain long-term disabilities or end-stage renal disease. There is no earnings cap on Medicare tax. Every dollar you earn is subject to the 1.45% rate.
Additional 0.9% for Higher Earners
Since 2013, an extra 0.9% Medicare surtax applies to earnings above thresholds set by filing status:
- Single or head of household: wages above $200,000
- Married filing jointly: combined wages above $250,000
- Married filing separately: wages above $125,000
Your employer begins withholding the additional 0.9% once your wages pass $200,000 in a calendar year, regardless of your filing status. If you’re married filing jointly and your combined income triggers the tax at a different threshold, you settle up when you file your return. The additional Medicare tax is entirely the employee’s responsibility. Your employer doesn’t match it.
2026 FICA Rates at a Glance
Employee and employer pay the same rates, so total contributions to each program are double what you see withheld:
- Social Security (OASDI): 6.2% employee + 6.2% employer = 12.4% total, on wages up to $184,500
- Medicare (HI): 1.45% employee + 1.45% employer = 2.9% total, on all wages with no cap
- Combined FICA: 7.65% from your paycheck + 7.65% from your employer = 15.3% total
On the first $184,500 of earnings, total FICA withholding is 7.65% per paycheck. After you hit the Social Security cap, only the 1.45% Medicare portion continues. Maximum Social Security withholding in 2026 comes out to $11,439 (6.2% × $184,500) for someone earning exactly the cap.
If You’re Self-Employed, It’s Called SECA
Working for yourself as a freelancer, sole proprietor, or independent contractor puts you under a different law, the Self-Employment Contributions Act, but it funds the same two programs. There’s no employer to cover the matching half, so you pay the full combined rate of 15.3%: 12.4% for Social Security and 2.9% for Medicare. The Additional Medicare Tax of 0.9% still kicks in once your self-employment income crosses the same filing-status thresholds.
You don’t pay 15.3% on your entire net profit. The IRS first reduces your net earnings by 7.65% (effectively multiplying by 92.35%) to mirror the fact that W-2 employees aren’t taxed on the employer’s share. So if your Schedule C shows $100,000 in net profit, your taxable self-employment earnings are $92,350, and your self-employment tax is roughly $14,130. You then deduct half of that tax when calculating your adjusted gross income, which lowers your income tax bill. All of this goes on Schedule SE, filed with your Form 1040.
Self-employed workers also don’t have withholding, so quarterly estimated payments to the IRS take its place. For 2026, those payments are due April 15, June 15, September 15, and January 15, 2027.
What FICA Is Not
FICA is not federal income tax, even though both come out of the same paycheck. Federal income tax goes to the U.S. Treasury’s general fund and pays for defense, infrastructure, and government operations. FICA goes only to the Social Security and Medicare trust funds. You could owe zero federal income tax and still owe FICA on every dollar you earn.
FICA also isn’t reduced by traditional 401(k) contributions. Deferring salary into a traditional 401(k) lowers your federal income tax withholding, but Social Security and Medicare taxes still apply to your full gross pay, including the money going into the plan. Roth 401(k) contributions are subject to both FICA and income tax. Only employer matching contributions escape FICA.
So when the question is FICA versus Social Security tax, the honest answer is that they aren’t rivals. FICA is the law. Social Security tax is one of the two withholdings it requires. Medicare tax is the other. What shows up on your pay stub as separate lines adds up to a single thing the tax code calls FICA.