If your pay stub has a line labeled FICA, that is the federal payroll tax taken out for Social Security and Medicare. For most workers it is 7.65% of gross wages — 6.2% for Social Security and 1.45% for Medicare. On a $2,500 biweekly paycheck, the FICA line should be $191.25: $155.00 for Social Security plus $36.25 for Medicare.
That line matters because it is different from federal income tax withholding. Income tax is an estimate that gets settled when you file. FICA is calculated paycheck by paycheck, your employer matches it with another 7.65%, and the year-to-date total follows you into your W-2. If the number on your stub looks off, there is usually a specific reason — and sometimes it is a real payroll mistake worth catching early.
FICA stands for the Federal Insurance Contributions Act. On a pay stub, it is rarely a mystery charge. It is the employee share of two payroll taxes that fund Social Security and Medicare. The Social Security part pays benefits to retirees, disabled workers, and surviving family members. The Medicare part helps fund hospital insurance for people age 65 and older.
Many employers do not print the word FICA at all. Instead, you may see two separate lines such as SS, Soc Sec, or OASDI for Social Security, and Med, HI, or Medicare for Medicare. OASDI means Old-Age, Survivors, and Disability Insurance. HI means Hospital Insurance. Different payroll software uses different labels, but the math underneath is the same.
There are two sides to the tax. You pay 7.65% as the employee. Your employer also pays 7.65% on the same wages, even though that employer half does not appear as a deduction from your pay. On $65,000 of wages, you pay $4,972.50 during the year and your employer sends in another $4,972.50. The government collects $9,945 total tied to that job.
Take a worker paid every two weeks who earns $2,500 gross per paycheck, or $65,000 a year. The FICA calculation has two pieces. Social Security is $2,500 multiplied by 6.2%, which is $155.00. Medicare is $2,500 multiplied by 1.45%, which is $36.25. Add them together and the FICA deduction is $191.25 for that check.
After 10 biweekly paychecks, gross year-to-date pay would be $25,000. The year-to-date FICA total should be $1,912.50 if there were no pre-tax items that change Social Security or Medicare wages and no midyear payroll changes. That year-to-date figure is an easy place to spot trouble. If your stub says $25,000 in gross pay but $2,600 in FICA, something does not line up.
Now compare a higher paycheck. A $120,000 salary paid biweekly is $4,615.38 per check. Social Security is $286.15, Medicare is $66.92, and total FICA is $353.08 per paycheck early in the year. At this salary, the worker stays below the 2026 Social Security wage base of $184,500, so the 6.2% piece continues all year. The math stays boring, which is exactly what you want from payroll.
The stub can look different if you have pre-tax deductions. Health insurance premiums paid through a cafeteria plan and HSA contributions made through payroll usually reduce wages subject to Social Security and Medicare. A traditional 401(k) contribution reduces income tax withholding but does not reduce FICA wages. That surprises people: a $200 401(k) contribution lowers the federal income tax line, while the FICA percentage is still figured on the pay before that 401(k) amount is removed.
Separate lines are often clearer than one combined FICA line. The Social Security line tells you whether you are still under the annual wage base. The Medicare line keeps running all year because Medicare tax has no wage cap. If the two lines are separated, you can check each rate on its own instead of trying to reverse-engineer one blended number.
Here is a quick way to read it. Suppose your Medicare wages for the pay period are $3,000. The Medicare deduction should be $43.50, because $3,000 times 1.45% equals $43.50. If Social Security wages are also $3,000 and you have not reached the cap, the Social Security deduction should be $186.00. Together they are $229.50, which is still 7.65% of $3,000.
The wage amounts printed near those lines matter as much as the tax amounts. Pay stubs often show current wages and year-to-date wages for each tax. A bonus, overtime shift, or retroactive pay adjustment can raise the current amount for one check. A correction can lower it. If the tax looks strange, do not start with the deduction. Start with the wage base the payroll system used, then apply the rate.
The most common midyear change is the Social Security cap. In 2026, Social Security tax applies only to the first $184,500 of wages from an employer. Once your year-to-date wages pass that amount, the 6.2% Social Security line stops for the rest of the year. Medicare continues. High earners often notice a slightly larger net paycheck late in the year for this reason.
The cap is applied per employer, not across your whole working life for that year. If you change jobs after earning $150,000 at the first employer, the new employer generally starts its own wage-base count. You could end up having Social Security tax withheld on more than $184,500 across both W-2s. The excess employee Social Security tax is generally claimed as a credit when you file your federal return, so keep both W-2s and check the totals.
Medicare has its own wrinkle. After wages from one employer pass $200,000 in a calendar year, the employer must withhold an extra 0.9% Medicare tax on wages above that threshold. This Additional Medicare Tax is employee-only; the employer does not match it. On a paycheck where $1,000 of wages falls above the threshold, that extra piece is only $9, but it can make the Medicare line look inconsistent if you are comparing it with an earlier check.
A change in job status can also change the picture. Some student employment, certain government jobs, and a few other special categories have different payroll-tax treatment. Most private-sector W-2 workers, though, should expect the standard 6.2% and 1.45% split. If your stub suddenly shows no FICA at all and you are in an ordinary W-2 job, ask payroll why before assuming you found a raise.
People often add up every tax line and call the whole thing FICA, but the stub is really showing different systems. Federal income tax withholding is based on your Form W-4, your pay frequency, and IRS withholding tables. It can change when you update your W-4, claim dependents, add extra withholding, or receive a bonus. FICA does not care about those W-4 choices. It follows wages and the payroll-tax rates.
That difference explains why two coworkers with the same gross pay can have different federal withholding but identical FICA. One may have a working spouse and extra withholding on line 4(c) of the W-4. The other may claim two children under 17. Their income tax lines differ. Their Social Security and Medicare lines should match if their taxable wages for FICA are the same.
State income tax is separate again. Texas and Florida workers may see no state income tax line. California and New York workers usually do. That state line does not change the FICA rate. When you use a FICA tax calculator, you are isolating only the Social Security and Medicare slice, not the full gross-to-net bridge. For the whole paycheck, a take-home pay calculator is the better tool.
First, find the current gross wages used for Social Security and Medicare. Some stubs call this FICA wages, Social Security wages, Medicare wages, or taxable wages. If pre-tax health premiums or payroll HSA contributions are involved, this number may be lower than your headline gross pay. Use the wage number printed for the tax, not just the salary amount you expected.
Second, do the simple rate test. Multiply Social Security wages by 6.2% and Medicare wages by 1.45%. Compare the result with the deduction lines, allowing for a few cents of rounding. Then look at year-to-date totals. Year-to-date Social Security tax divided by year-to-date Social Security wages should be close to 6.2% until you hit the $184,500 cap. Year-to-date Medicare divided by Medicare wages should be close to 1.45%, plus the extra 0.9% on wages above the relevant threshold if that applies.
Third, check whether the pay period had something unusual. Overtime, a bonus, paid leave cash-outs, retro pay, or a corrected prior check can all move one stub without meaning the whole year is wrong. A single odd check is a question. A pattern that repeats for several checks is a payroll issue to raise promptly, while the correction is still easy.
If the numbers still do not work, bring the stub to payroll and ask a narrow question: which wage amount was used for Social Security and Medicare in this pay period, and why does it differ from gross pay? That question gets a useful answer much faster than saying the check looks wrong. Payroll departments make mistakes, especially after a system conversion, a job change, or a new deduction setup. Catching a $40 error in February is simple. Rebuilding it the following January is not.
FICA on a pay stub is the employee payroll tax for Social Security and Medicare. In 2026 it is usually 7.65% of FICA wages: 6.2% for Social Security up to $184,500 and 1.45% for Medicare on all wages.
Multiply the Social Security wage amount on the stub by 6.2% and the Medicare wage amount by 1.45%. On a $2,500 biweekly paycheck with no adjustments, that is $155.00 plus $36.25, for $191.25 total.
OASDI is the formal name for the Social Security program: Old-Age, Survivors, and Disability Insurance. An OASDI line is the 6.2% Social Security tax. A line labeled HI is the 1.45% Medicare hospital insurance tax.
The usual reason is that your year-to-date wages from that employer reached the 2026 Social Security wage base of $184,500. After that point, the 6.2% Social Security tax stops for the year, but Medicare tax continues.
No. A traditional 401(k) contribution reduces federal income tax withholding, but it does not reduce wages subject to Social Security and Medicare. Some other pre-tax items, such as cafeteria-plan health premiums and payroll HSA contributions, can reduce FICA wages.
Check the Social Security and Medicare wage amounts printed on the stub, multiply them by 6.2% and 1.45%, and compare the year-to-date totals. If the gap is more than rounding or an explained cap or Additional Medicare Tax issue, ask payroll which wage base was used for that pay period.