What Are FICA Taxes and How Are They Calculated?
Every working American sees two lines on their pay stub labeled "Social Security" and "Medicare." Together, these are FICA taxes — and they're among the most misunderstood deductions on a paycheck. This guide explains exactly what FICA is, how the rates work, what the wage base limits mean, and what self-employed workers need to know.
What Does FICA Stand For?
FICA stands for the Federal Insurance Contributions Act, a U.S. federal law enacted in 1935 that established the payroll tax system funding Social Security and Medicare. The law requires both employees and employers to contribute a percentage of wages toward these two federal programs.
Social Security provides retirement benefits, disability income, and survivor benefits to eligible workers and their families. Medicare provides health insurance for Americans aged 65 and older, as well as certain younger individuals with qualifying disabilities. Your FICA contributions today directly support current beneficiaries of both programs while building your own future eligibility.
Unlike income tax, which varies based on your bracket and deductions, FICA is a flat tax applied to every dollar of wages. There's no standard deduction, no filing status adjustment, and no way to reduce it through tax credits. It's calculated on your gross wages before any pre-tax benefit deductions are applied (with one exception: FICA is calculated after pre-tax deductions for Section 125 cafeteria plans).
The Two Components of FICA
Social Security Tax (OASDI)
The Social Security portion of FICA is officially called the Old-Age, Survivors, and Disability Insurance (OASDI) tax. The employee rate is 6.2%, and your employer contributes a matching 6.2%, bringing the total to 12.4% on your wages.
The critical feature of Social Security tax is the wage base limit. For 2026, this limit is $176,100. Once your earned wages reach this threshold in a calendar year, Social Security withholding stops entirely for the rest of the year. You'll notice a slight bump in your take-home pay when you cross this threshold, typically in the later months of the year for higher earners.
The wage base limit is adjusted annually by the Social Security Administration based on changes in average wages nationwide. In 2024 it was $168,600, rising to $176,100 in 2026 — meaning the ceiling increases most years.
Medicare Tax (HI)
The Medicare portion is officially called the Hospital Insurance (HI) tax. The employee rate is 1.45%, and again your employer matches with another 1.45%, for a total of 2.9%.
Unlike Social Security, Medicare has no wage base cap. You pay 1.45% on every dollar of wages regardless of how much you earn. A person making $500,000 pays Medicare tax on every dollar of that income.
High earners face an additional Medicare obligation. The Additional Medicare Tax of 0.9% applies to wages above $200,000 for single filers and $250,000 for married filing jointly. Employers are required to withhold this additional 0.9% once an employee's wages exceed $200,000 in a year — even if the employee's combined household income doesn't reach the threshold. Any over- or under-withholding of the Additional Medicare Tax is reconciled when you file your annual tax return.
FICA Tax Rates at a Glance (2026)
| Tax | Employee Rate | Employer Rate | Wage Limit |
|---|---|---|---|
| Social Security | 6.2% | 6.2% | $176,100 |
| Medicare | 1.45% | 1.45% | None |
| Additional Medicare Tax | 0.9% | None | Above $200K (single) |
How FICA Is Calculated: A Worked Example
Let's walk through a concrete example. Suppose you earn $80,000 per year and are paid biweekly (26 pay periods). Your gross pay per check is $3,076.92.
Note that your employer pays an identical $6,120.14 on top of your wages — this is an additional payroll cost the employer bears, effectively making the true tax 15.3% of your wages from the government's perspective, even though you only see 7.65% on your stub.
Employer Matching: The Hidden FICA Cost
One of the most important things to understand about FICA is the employer match. For every dollar of FICA you pay, your employer pays an equal amount directly to the IRS on your behalf. This means the true cost of FICA to fund these programs is double what appears on your stub.
The employer's share doesn't appear on your pay stub because it doesn't come from your wages — it's an additional cost the employer bears above and beyond your salary. However, many economists argue that the employer's share is indirectly borne by employees in the form of lower wages, since employers factor total compensation costs (including payroll taxes) when setting salary levels.
When you're self-employed, this distinction disappears entirely — you pay both halves yourself, which is why self-employment tax is notably higher than what W-2 employees see deducted from their paychecks.
FICA for Self-Employed Workers
If you're a sole proprietor, freelancer, or independent contractor, you don't have an employer to split the FICA bill. Instead, you pay self-employment tax, which covers both the employee and employer portions. The rates are:
- Social Security: 12.4% (up to $176,100 in net self-employment income)
- Medicare: 2.9% (on all net self-employment income)
- Total self-employment tax: 15.3%
The good news: self-employed workers get two tax breaks to offset this burden. First, you calculate self-employment tax on 92.35% of your net self-employment income (not 100%), which approximates the deduction W-2 employees get because their employer's share doesn't count as wages. Second, you can deduct 50% of your self-employment tax from your gross income when calculating your federal income tax, reducing your income tax bill.
Self-employed workers are also required to make quarterly estimated tax payments that include self-employment tax, since there's no employer withholding these amounts automatically.
Why FICA Can't Be Reduced Through Deductions
A common misconception is that maxing out your 401(k) reduces your FICA taxes. For traditional (pre-tax) 401(k) contributions, this is only partially true. Traditional 401(k) deferrals do reduce your federal and state income taxes, but they do not reduce FICA. Social Security and Medicare are calculated on your gross wages before 401(k) deferrals.
The one significant exception is contributions to a Section 125 cafeteria plan. Health insurance premiums, FSA contributions, and HSA contributions made through an employer's Section 125 plan are exempt from both income tax and FICA. This makes employer-sponsored health coverage particularly valuable from a tax standpoint — a $500/month health premium deducted pre-tax saves you roughly $38.25 per month in FICA alone, in addition to income tax savings.
What FICA Taxes Fund: Your Future Benefits
Your FICA contributions directly determine your eligibility for Social Security and Medicare benefits later in life. The Social Security Administration tracks your earnings history based on the wages reported through FICA withholding. To qualify for Social Security retirement benefits, you generally need at least 40 work credits (roughly 10 years of covered employment), and your eventual benefit amount is calculated from your highest 35 years of earnings.
Medicare eligibility at age 65 also depends on sufficient work history — typically 40 quarters of Medicare-covered employment. Workers with fewer work credits may still access Medicare but pay higher premiums.
See Your FICA Deductions Calculated
Use our free pay stub calculator to see exactly how much Social Security and Medicare will be withheld from each of your paychecks, broken down alongside federal and state income tax.