AfterTaxLabWhat is FICA? The payroll tax on every paycheque
FICA stands for the Federal Insurance Contributions Act, a mandatory payroll tax withheld from employee earnings in the United States. Employers deduct this amount automatically from your gross pay before you receive your cheque. These funds are designated specifically to support the Social Security and Medicare systems, providing a foundation for public retirement and health coverage benefits.
Workers see these withholdings itemized on their pay stubs every pay cycle. Because FICA is a federal requirement, the amount is calculated based on your total gross income rather than your final take-home pay. Understanding how these figures are derived helps you see exactly where your paycheck contributions go before your income tax is even calculated.
FICA at four salary levels
Employee side only, as modelled by the AfterTaxLab engine. The engine does not add an employer share.
| Gross salary | Social Security | Medicare | Medicare surtax | FICA total |
|---|---|---|---|---|
| $50,000 | $3,100 | $725 | $0 | $3,825 |
| $100,000 | $6,200 | $1,450 | $0 | $7,650 |
| $184,500 | $11,439 | $2,675 | $0 | $14,114 |
| $250,000 | $11,439 | $3,625 | $450 | $15,514 |
The two halves of FICA
The two halves of FICA consist of separate contributions for Social Security and Medicare. For a salary of $100,000, the tax includes $6,200 for Social Security and $1,450 for the Medicare portion. Employers are responsible for withholding these specific portions from your paycheck, ensuring both programs receive the necessary funding to maintain operations for current and future beneficiaries.
Where the Social Security part stops
Where the Social Security part stops is determined by the annual wage base limit. Once your earnings reach $184,500, Social Security withholdings cease for the remainder of the year. This cap exists because Social Security contributions are intended to cover a specific range of income, whereas Medicare taxes continue to apply regardless of how much your total salary increases throughout the calendar year.
Why FICA ignores your deductions
Why FICA ignores your deductions is rooted in its design as a flat tax on gross earnings. Unlike income taxes that allow for adjustments based on savings or expenses, FICA is charged on your total gross pay. Even at a $250,000 salary, your Medicare obligation continues, and a surtax adds $450 to your total tax bill to account for higher earnings.
What is FICA? The payroll tax on every paycheque: common questions
Is FICA the same as federal income tax?
No, FICA is a separate payroll tax dedicated to Social Security and Medicare programs. While your federal income tax fluctuates based on your personal deductions and taxable income, FICA is calculated directly from your gross pay. It is a flat-rate obligation that applies to workers regardless of their individual tax filing status.
Why do my FICA taxes stop increasing at certain levels?
The Social Security portion of FICA stops growing once you reach the wage base of $184,500. This is a federal limit on the amount of income subject to the Social Security tax. However, the Medicare portion of the tax does not have a similar cap and continues to apply to all earned wages.
Do my retirement contributions reduce my FICA tax?
No, contributions to 401(k) or similar retirement plans do not reduce your FICA tax. Because these taxes are calculated on your gross pay, they do not account for pre-tax deductions that lower your income tax liability. You are responsible for the full FICA amount calculated from your total earnings before those retirement savings are removed.
What happens when I earn more than $250,000?
When you earn more than $250,000, your FICA taxes include the standard Medicare rates plus an additional surtax. For example, at a $250,000 salary, the surtax adds $450 to your total tax burden. While the Social Security portion stays fixed at the cap, your total Medicare obligation continues to scale with your higher compensation levels.
Figures calculated with the AfterTaxLab 2026 engine: federal brackets and standard deduction ($16,100 single), Social Security wage base $184,500, published 2026 state rates. Estimates for planning only — not tax advice. Last verified 21 Sep 2026 · methodology.