The FICA Cap Explained: Why High Earners Stop Paying Social Security Mid-Year

FICA — the Federal Insurance Contributions Act — is the payroll tax that funds Social Security and Medicare. Most people see it come out of every paycheck and assume it's a fixed percentage forever. But Social Security has a ceiling, and understanding it explains why some high earners get a noticeable pay bump partway through the year.

The two parts of FICA

FICA is really two taxes bundled together:

• Social Security: 6.2% of your wages, but only up to an annual cap.
• Medicare: 1.45% of your wages, with no cap at all.

Together that's 7.65% withheld from a typical paycheck. Your employer pays a matching 7.65% on your behalf, which you never see.

The Social Security wage cap

For 2025, the Social Security tax applies only to the first $176,100 of wages. This is called the wage base or the FICA cap, and it rises most years with inflation. Once your year-to-date earnings pass that figure, your employer stops withholding the 6.2% Social Security tax for the rest of the year.

Medicare has no cap — and adds a surtax

While Social Security stops at the wage base, Medicare never does. The 1.45% applies to every dollar you earn. On top of that, an Additional Medicare Tax of 0.9% kicks in on wages above $200,000 for single filers ($250,000 for married filing jointly). So the highest earners actually see their Medicare withholding increase mid-year, even as Social Security disappears.

Why it feels like a mid-year raise

Because the 6.2% Social Security tax simply stops once you hit the cap, your take-home pay rises for the remainder of the year without any change to your salary. On a $250,000 income, that's roughly $900 more per month in the final stretch of the year. It's easy to mistake this for a payroll change — it's just the cap doing its job.

How to plan for it

The smart move is to budget around your January take-home, when full FICA withholding is in effect, rather than the inflated end-of-year checks. Treat the mid-year bump as temporary — a good window to boost savings, pay down debt, or make an extra retirement contribution — rather than a permanent raise you build recurring expenses around.