StubRate · Guides · 7 min read
FICA, Social Security, and Medicare: The Paycheck Line People Skip
FICA is 7.65% of most wages—Social Security plus Medicare. It is not federal income tax, and a 401(k) does not always stop it.
FICA is not the federal income-tax brackets
Federal income tax uses brackets and a standard deduction. FICA does not care about your filing status the same way. For most workers it is 6.2% Social Security plus 1.45% Medicare, taken from wages. High earners stop paying the Social Security piece after the annual wage base; Medicare generally continues.
That is why two people in the same tax bracket can still see a stubborn 7.65% line. It is not a rounding error. It is a different tax.
Benefits change FICA more than people think
A traditional 401(k) lowers income tax and still usually sits in the FICA wage base. Health insurance premiums that qualify as pre-tax often lower both. Mixing those up is why a “pre-tax 10% to 401(k)” change does not shrink the FICA line as much as you hoped.
StubRate treats 401(k) and health that way so the estimate matches a typical W-2, not a wish.
Additional Medicare tax is a high-earner extra
An extra 0.9% Medicare tax can apply above a high income threshold. StubRate’s educational model does not fully recreate that cliff. If you are well into six figures, your real Medicare line can be a bit heavier than the 1.45% everyone quotes.
Use this guide to understand the 7.65% everyone pays, then confirm high-earner details with payroll or a professional.
FAQ
What is FICA on a paycheck?
FICA is Social Security (6.2%) plus Medicare (1.45%) on most wages, totaling 7.65% until you hit the Social Security wage base. It is separate from federal income tax.
Does a 401(k) reduce FICA?
Traditional 401(k) deferrals usually still face FICA. Typical employer health premiums withheld pre-tax under a cafeteria plan often reduce the FICA wage base. StubRate follows that split.