FICA explained
FICA — the Federal Insurance Contributions Act — is the combined Social Security tax (6.2%) and Medicare tax (1.45%) on your paycheck. It funds Social Security and Medicare benefits.
In plain English
The plain-English version
FICA is two taxes bundled together: Social Security and Medicare. Your employer takes 7.65% of most wages from your paycheck and matches that amount itself.
Social Security tax (OASDI) — 6.2%
You pay 6.2% of your wages up to the annual wage base. In 2025, that base is $176,100. Once your year-to-date wages cross the base, Social Security stops withholding for the rest of the year. Your employer pays a matching 6.2%.
Medicare tax — 1.45% (plus 0.9% over $200,000)
Medicare is 1.45% of all wages — there is no wage base. Your employer matches 1.45%.
An Additional Medicare Tax of 0.9% applies to wages over $200,000 in a calendar year (employer withholding threshold). The employer is not required to match the additional 0.9%. Your actual Additional Medicare liability depends on your filing status — verify on your tax return.
Why FICA looks separate from federal income tax
Federal income tax depends on your W-4 (filing status, dependents, extra withholding). FICA is a flat percentage with no W-4 adjustment. They fund different programs and use different rules.
Worked example
| Pay period gross | Social Security 6.2% | Medicare 1.45% | Total FICA |
|---|---|---|---|
| $2,000 | $124.00 | $29.00 | $153.00 |
| $5,000 | $310.00 | $72.50 | $382.50 |
| $10,000 | $620.00 | $145.00 | $765.00 |
Things worth checking on your stub
- Social Security should be exactly 6.2% of taxable wages up to the wage base.
- Medicare should be exactly 1.45% of all taxable wages.
- If wages YTD are over $200,000, expect to see an extra 0.9% Medicare line.
- If you contribute to a traditional 401(k), it does not reduce FICA — only federal income tax.
- If you contribute to an HSA via payroll, it usually does reduce FICA.
What to check on your pay stub
- Social Security line = 6.2% × FICA-taxable wages (until you cross $176,100 YTD).
- Medicare line = 1.45% × FICA-taxable wages.
- If YTD wages over $200,000, expect a separate Additional Medicare line at 0.9%.
- Pre-tax HSA, FSA, and Section 125 health premiums DO reduce FICA wages.
- Traditional 401(k) does NOT reduce FICA wages.
If your FICA does not match the standard 6.2% / 1.45% on the right wage base, ask payroll which figure they used as FICA-taxable wages. Use the Ask Payroll Generator to draft a polite, specific message in 30 seconds.
Official sources
- IRS Topic 751 — Social Security and Medicare Withholding Rates — IRS · 2025 · last verified 2025-04-01
- IRS — Questions and Answers for the Additional Medicare Tax — IRS · 2025 · last verified 2025-04-01
- SSA — Contribution and Benefit Base — SSA · 2025 · last verified 2025-04-01
Common questions
What is FICA on my pay stub?▾
FICA stands for Federal Insurance Contributions Act. It is the combined Social Security tax (6.2%) and Medicare tax (1.45%) — 7.65% total on most wages.
Why is FICA separate from federal income tax?▾
They fund different programs and are calculated differently. Federal income tax depends on your W-4. FICA is a flat percentage of your wages with no W-4 adjustment.
Is there a cap on FICA?▾
Social Security stops once your wages cross the annual wage base ($176,100 in 2025). Medicare has no cap. An additional 0.9% Medicare tax applies above $200,000.