FICA Taxes

FICA, the Federal Insurance Contributions Act tax, is the payroll line funding Social Security and Medicare: 6.2% of wages up to the $184,500 base for 2026 plus 1.45% of all wages with no cap. The employee pays the combined 7.65% on every paycheck, and the employer matches it, so a $100,000 salary really costs $107,650. An additional 0.9% Medicare tax applies above $200,000 of wages for single filers and $250,000 joint, withheld by the employer once wages pass $200,000.

The tax buys the two benefits Americans will actually draw: Social Security credits and Medicare enrollment at 65. Credits are earned at up to four quarters a year, with 40 needed for eligibility. The wage base makes the line regressive at the top, because the 6.2% stops at $184,500 while the 1.45% never stops. The self-employed pay both halves as the 15.3% self-employment tax. Payroll deductions for HSAs and Section 125 benefits are the only legal route around the line entirely.

Payroll runs the machinery. Every paycheck is cut with 6.2% Social Security withholding until wages hit the $184,500 base, then 1.45% Medicare continues, and the employer deposits a matching 7.65% with the IRS. On a $100,000 salary that is $6,200 plus $1,450, a $7,650 line on the payslip and a matching $7,650 the employee never sees. The W-2 reports the full year: Social Security wages, Medicare wages, and the amounts withheld.

The wage base is the interesting edge. A $250,000 earner pays Social Security on the first $184,500 ($11,439), Medicare on the full $250,000 ($3,625), and the 0.9% additional tax on the last $50,000 ($450): $15,514 employee-side, while the employer matches only the base 7.65%. Above the base the marginal FICA rate drops to 1.45%, not zero, which is why the year-end bonus is never tax-free. The additional Medicare tax shares its thresholds with the net investment income tax but taxes wages, not investments.

The credits are the point. Each year of covered wages earns up to four quarters of Social Security credit, and 40 quarters make a worker eligible; the benefit formula then weights lower lifetime earnings more heavily. The self-employed run the same machinery on Schedule SE at 92.35% of net profit, both halves, with the deductible half returned as an above-the-line adjustment. Section 125 payroll deductions, the HSA and the FSAs, skip the 7.65% line entirely, which is the only legal discount on a tax everyone else pays in full.

FICA is the second-largest line on most payslips after income tax withholding, and it is the funding behind the two benefits the reader will actually draw. The employer's invisible half changes every compensation comparison: a $100,000 salary costs $107,650, and a contractor rate should be grossed up for the same reason. The caps make the line regressive at the top and the payroll deductions make it avoidable at the bottom.

I watched a colleague named Brent (yes, that Brent) pay his health premium by direct deposit out of habit while enrolled in the HSA-eligible plan. Payroll pretax would have skipped FICA on $4,400 of contributions, the $337 a year he mailed to the IRS for nothing. Three years of premiums at the wrong rail cost him roughly $1,000.

The highest-leverage thing most Americans can do is route every tax-advantaged deferral through payroll where the plan allows it, because the FICA skip is the only legal discount on the line. Check the take-home with the salary take-home paycheck calculator, see the credit side in the social security entry, and read the skip mechanics in the health savings account entry.