Social Security Tax
A 6.2% payroll tax on wages up to the annual wage base ($176,100 in 2025), matched by your employer. Funds Social Security retirement, disability, and survivor benefits.
Social Security tax is the larger component of FICA, charged at 6.2% of wages up to the annual wage base limit. For 2025, the wage base is $176,100, meaning the maximum employee Social Security tax is $10,918.20. Income above the wage base is not subject to this tax.
Your employer matches the 6.2%, so a total of 12.4% of your wages goes toward Social Security. Self-employed individuals pay the full 12.4% through self-employment tax, though they deduct half as a business expense.
The Social Security wage base is adjusted annually for inflation based on the national average wage index. Your Social Security benefits in retirement are calculated using your highest 35 years of earnings (adjusted for inflation), so paying into the system for more years and at higher amounts generally increases your future benefits.
How it works
Social Security tax is the larger of the two FICA components, charged at 6.2% of wages, but only up to the annual wage base — $176,100 for 2025. Once your cumulative wages for the year cross that amount, no further Social Security tax is withheld from your remaining paychecks for the rest of the year, which is different from Medicare tax, which has no such cap and applies to every dollar you earn.
Your employer withholds 6.2% from each paycheck and reports the totals in Box 4 of your W-2, alongside your Social Security wages in Box 3. Your employer also contributes a matching 6.2% on your behalf, so 12.4% of your wages in total flows to Social Security once employer and employee shares are combined. For 2025, the maximum possible employee Social Security tax is $10,918.20, reached once wages hit the $176,100 wage base.
Self-employed individuals pay the full 12.4% themselves through self-employment tax rather than splitting it with an employer, though they deduct half as an above-the-line deduction. Workers with multiple employers in the same year sometimes end up with more than the maximum withheld in total, since each employer withholds independently without visibility into the others' payroll — that excess amount can be claimed back as a credit when filing. Your future Social Security retirement benefit is calculated from your highest 35 years of earnings, so paying into the system consistently, and at higher wages, generally increases your eventual benefit.
Example: Social Security tax stopping at the wage base
An employee earns $200,000 in wages for 2025, which is above the $176,100 Social Security wage base.
Social Security tax is only withheld on the first $176,100 of wages, at 6.2%, for a total of $10,918.20 — the maximum for the year. The remaining wages above the wage base are still subject to the uncapped 1.45% Medicare tax, but no additional Social Security tax is withheld once the cap is reached.
Frequently asked questions
Does Social Security tax apply to all of my income?
What is the maximum Social Security tax I can pay in a year?
What if I overpaid Social Security tax because I had multiple employers?
Related Terms
FICA
Federal Insurance Contributions Act taxes that fund Social Security (6.2%) and Medicare (1.45%). Both employees and employers pay FICA, totaling 15.3% on wages.
Medicare Tax
A 1.45% payroll tax on all wages with no income cap, matched by employers. High earners pay an Additional Medicare Tax of 0.9% on wages over $200,000 (single).
Wage Base
The maximum amount of earnings subject to Social Security tax in a given year. For 2025, the wage base is $176,100. Earnings above this amount are exempt from Social Security tax.
Self-Employment Tax
The combined Social Security (12.4%) and Medicare (2.9%) tax paid by self-employed individuals — effectively both the employee and employer shares of FICA, totaling 15.3%.