FICA is the name of the statute behind two rows rather than the name of a row. Read down the required deduction block of a typical document and the four letters are often absent; what appears instead is a Social Security line and a Medicare line, each with its own amount and its own running total.
Each half has its own rule. The employee share of Social Security runs at 6.2% on wages up to an annual ceiling published each year, so the row stops once the year-to-date figure passes it. The Medicare share runs at 1.45% with no ceiling, so it charges every dollar of every period. The employer pays a matching amount of its own, not taken from these wages.
The frequent mix-up is with income tax withholding. FICA is the pair on fixed rates that ignore filing status, dependents or a second job, because the funds they finance are insurance programs with defined rates. Federal income tax comes from tables and from what the employee has declared, which is why that row changes after a new form and these two never do.
Across a year the pair diverges. Medicare keeps a constant relationship to taxable wages all twelve months, while the Social Security row can fall to zero in the final weeks with no change to gross, then resume at full rate on the opening period of the next year. A plateaued total beside a still-climbing one is the two rules behaving normally.
Two Fixed Rates on One Weekly Gross
| Line | Amount |
|---|---|
| Gross pay for the week | $2,000 |
| Social Security at 6.2% | −$124 |
| Medicare at 1.45% | −$29 |
| Pay left after the two FICA rows | $1,847 |
The same 2,000 gross produces two deductions at different rates, and the rows add exactly: 124 plus 29 is 153, which is 7.65% of the week and leaves 1,847. Nothing here depends on filing status. The figures are illustrative for one period and do not describe anyone’s actual wages.
Frequently asked questions
What is the difference between FICA and income tax?
One pair funds insurance programs and the other funds general government operations, and the practical difference on the page is how each amount is derived. The two rates are fixed percentages that stay identical from January to December for a given wage, while income tax responds to filing status and the tables. That is why one row changes after a form revision and the other pair does not.
Why did my Social Security deduction stop near the end of the year?
Because that row runs only up to an annual ceiling on wages, and a higher earner can pass it before the last months arrive. The running total beside the row is the evidence: it plateaus at the same figure on every remaining document while the Medicare total keeps climbing. The ceiling itself is published each year, so a fixed number copied into an article is often the wrong one for whoever reads it.
Does FICA apply to bonuses and overtime pay?
It runs on the same pay base as the wages it sits beside, so an overtime premium, a commission or a year-end bonus is inside the amount both rates use. The consequence shows up as a period where the two rows are simply larger, in proportion, rather than behaving differently from an ordinary week. Only repayments handled as expense reimbursements fall outside that base.
Where to read on
- the longer breakdown of both rates and the matching employer share
- the income tax row these two are so often confused with
- the running totals that show a capped row plateauing
- which boxes carry the two totals at year end
- generate a stub that prints both tax rows in your amounts
- FICA, wage base and OASDI in the 25-term glossary