FICA covers four separate payroll taxes, not one
FICA is the shorthand for the Federal Insurance Contributions Act, and it bundles together four different taxes that come out of your paycheck. Two of them fund Social Security, one funds Medicare hospital insurance, and one funds Medicare supplemental insurance. Your employer pays a matching amount for each one. Understanding what each tax funds helps you see where your money actually goes and what you might receive in return.
The four taxes are Social Security (6.2%), Social Security on wages above a cap (0.9%), Medicare (1.45%), and Additional Medicare (0.9% on high earners). The first three explore to nearly every worker. The fourth applies only if you earn above a threshold that varies by filing status — $200,000 for single filers, $250,000 for married filing jointly, $125,000 for married filing separately.
Key Takeaways
- FICA includes Social Security tax (6.2%), Medicare tax (1.45%), and Additional Medicare tax (0.9% for high earners), each funding a different government program.
- Your employer matches your FICA contributions dollar-for-dollar, so the total cost to fund these programs is double what appears on your paycheck.
- Social Security tax only applies to the first $168,600 of your annual income in 2024, but Medicare tax applies to all wages with no cap.
- Additional Medicare tax kicks in at $200,000 for single filers and $250,000 for married couples filing jointly, and you pay it on all income above that threshold.
- Self-employed workers pay both the employee and employer portions of FICA taxes, which is why self-employment tax is roughly double the employee rate.
Social Security tax: 6.2% on wages up to a cap
Social Security tax funds the retirement, disability, and survivor benefits program. In 2024, you pay 6.2% on the first $168,600 of wages you earn in a calendar year. Once you hit that cap, no more Social Security tax comes out of your paycheck for the rest of that year. Your employer also pays 6.2% on your behalf, up to the same cap.
The wage cap changes every year based on average wage growth. If you work for multiple employers in the same year, each one withholds Social Security tax independently up to the cap, which can mean you overpay. You claim the overpayment as a credit on your tax return, but it takes months to get the refund. Self-employed workers calculate their own Social Security tax on Schedule SE and pay both portions.
Medicare tax: 1.45% on all wages with no limit
Medicare tax funds the hospital insurance part of Medicare — Part A, which covers inpatient hospital stays, skilled nursing, hospice, and some home health care. Unlike Social Security tax, there is no wage cap. You pay 1.45% on every dollar you earn, no matter how much you make. Your employer matches this 1.45%.
Medicare tax applies to W-2 wages, tips, and certain other compensation. It also applies to self-employment income. Because there is no cap, high earners pay significantly more Medicare tax than Social Security tax over the course of a year. This tax funds only Part A; Parts B, C, and D (doctor visits, supplemental coverage, and prescription drugs) are funded separately through premiums and general revenue.
Additional Medicare tax: 0.9% on high earner income
Additional Medicare tax is a newer tax that started in 2013 and applies only to workers above certain income thresholds. If you are single, it kicks in at $200,000. If you are married filing jointly, it kicks in at $250,000. If you are married filing separately, it kicks in at $125,000. You pay 0.9% on all income above your threshold.
Unlike the other FICA taxes, your employer does not match Additional Medicare tax. You pay the full 0.9% yourself. The revenue funds the same Medicare Part A hospital insurance program as the regular 1.45% Medicare tax. Employers must withhold this tax if your wages exceed the threshold, but the calculation can be tricky if you have multiple jobs or if your spouse also works — the thresholds are per person, not per household, so a married couple can each earn up to $250,000 without triggering the tax.
How FICA appears on your pay stub and tax return
On your pay stub, you will see separate line items for Social Security tax, Medicare tax, and Additional Medicare tax (if applicable). These are withheld from your gross pay before you receive your net pay. Your employer's matching contributions do not appear on your pay stub — they are a cost to the employer that you do not see directly.
On your Form W-2, Box 4 shows Social Security tax withheld, Box 6 shows Medicare tax withheld, and Box 7 shows Social Security wages. If you overpaid Social Security tax due to multiple jobs, you claim the overpayment on Form 1040, line 24. Additional Medicare tax withheld appears in Box 6 of your W-2 combined with regular Medicare tax, but the IRS separates them when processing your return.
Self-employed workers and FICA equivalents
If you are self-employed, you do not pay FICA taxes directly. Instead, you pay self-employment tax on Schedule SE, which covers both the employee and employer portions of Social Security and Medicare tax. The rate is 15.2% on net self-employment income: 12.4% for Social Security (up to the annual cap) and 2.9% for Medicare (no cap).
Self-employed workers also owe Additional Medicare tax if net self-employment income plus other wages exceed the threshold for their filing status. You calculate this on Form 8959 and report it on your Form 1040. You can deduct half of your self-employment tax as an adjustment to income, which reduces your taxable income but does not reduce the tax itself.
What FICA does not include
FICA does not fund federal income tax withholding, which is a separate calculation based on your W-4 form. It also does not fund unemployment insurance (FUTA), which is paid entirely by employers. State income tax and state unemployment insurance are separate systems that vary by state.
FICA also does not cover Medicare Parts B, C, or D. Part B (doctor visits and outpatient care) is funded through monthly premiums that most retirees pay. Part C (Medicare Advantage plans) and Part D (prescription drug coverage) are funded through premiums and general revenue. Long-term care, dental, vision, and hearing are not covered by Medicare at all, regardless of FICA contributions.
Frequently Asked Questions
Why do I pay Social Security tax if I might not get Social Security benefits?
Social Security tax funds not just retirement benefits but also disability and survivor benefits. Even if you never claim retirement benefits, your family may receive survivor benefits if you die, or you may receive disability benefits if you become unable to work. The tax also builds a record of earnings that affects your benefit amount if you do claim.
Can I opt out of FICA taxes?
No. FICA taxes are mandatory for nearly all workers. The only exceptions are certain religious groups that have obtained an exemption, some government employees hired before specific dates, and nonresident aliens on certain visas. If you are a U.S. citizen or permanent resident working in the United States, you must pay FICA taxes.
What happens to FICA taxes if I change jobs?
Each employer withholds FICA taxes independently. If you change jobs mid-year and your combined wages exceed the Social Security cap, you may overpay Social Security tax. You claim the overpayment on your tax return. Medicare and Additional Medicare tax withholding continues with each employer based on your wages at that job.
Do FICA taxes go into a personal account with my name on it?
No. FICA taxes go into the Social Security and Medicare trust funds, which are shared pools. Your benefit amount is based on your earnings record and age, not on the amount you paid in. Someone who paid more in FICA taxes may receive the same or less in benefits than someone who paid less, depending on when they claim and how long they live.
Is Additional Medicare tax the same as the Medicare surtax?
Yes. Additional Medicare tax and the Medicare surtax are the same thing — the 0.9% tax on high earner income that started in 2013. It is called a surtax because it is an additional tax on top of the regular 1.45% Medicare tax. Both terms appear in IRS documents and tax software.