The Social Security tax rate is 6.2% of your wages if you work for an employer, and your employer pays a matching 6.2%. If you’re self-employed, you owe the full 12.4% yourself. Either way, the tax applies only to the first $184,500 you earn in 2026, so the most an employee can pay in a single year is $11,439.1Social Security Administration. Contribution and Benefit Base
What Employees Pay
If you’re on a payroll, 6.2% comes out of every paycheck for Social Security. Your employer withholds it automatically and sends it to the federal government.2Office of the Law Revision Counsel. 26 USC 3101 – Rate of Tax On top of that, your employer pays its own 6.2% on the same wages.3Office of the Law Revision Counsel. 26 USC 3111 – Rate of Tax Combined, 12.4% of your wages flow into the Social Security trust funds, half from you and half from your employer.
On a pay stub, this deduction is often labeled “OASDI,” for Old-Age, Survivors, and Disability Insurance. The percentage is the same for everyone, but the dollar amount per pay period depends on your earnings. Once your wages for the year reach $184,500, the withholding stops. The maximum any single employee will pay for 2026 is $11,439, and the employer pays an identical $11,439.
Your employer is responsible for depositing both shares with the U.S. Treasury, typically by electronic funds transfer on a semi-weekly or monthly schedule.4Internal Revenue Service. Publication 15 (2026), Employer’s Tax Guide
What Self-Employed Workers Pay
If you work for yourself as a freelancer, independent contractor, or small-business owner, you cover both the employee and employer sides. Your Social Security tax rate is 12.4% of net self-employment income.5Office of the Law Revision Counsel. 26 USC 1401 – Rate of Tax
The 12.4% doesn’t apply to your entire net profit, though. The IRS first reduces your net earnings by 7.65%, so Social Security and Medicare taxes only hit 92.35% of your net self-employment income. This mirrors the break traditional employees get, because an employer’s share of FICA isn’t treated as taxable wages.6Internal Revenue Service. Topic No. 554, Self-Employment Tax
You can also deduct half of your total self-employment tax (Social Security plus Medicare) when figuring your adjusted gross income. The deduction goes on Schedule 1 and lowers your income tax, but it does not lower the self-employment tax itself.7Office of the Law Revision Counsel. 26 USC 164 – Taxes You calculate the tax on Schedule SE and file it with your Form 1040.8Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)
You don’t have automatic withholding, so you’re expected to send in quarterly estimated payments. The due dates are April 15, June 15, September 15, and January 15 of the following year. Miss a deadline or underpay, and the IRS can charge an underpayment penalty based on the shortfall and how late you are.9Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
The 2026 Wage Base Limit
Social Security tax doesn’t apply to every dollar you earn. Each year, the government sets a cap, formally called the contribution and benefit base. For 2026, that cap is $184,500.1Social Security Administration. Contribution and Benefit Base Once your earnings pass that number during the calendar year, the 6.2% withholding stops for the rest of the year.
The Social Security Administration recalculates the cap each year using the National Average Wage Index, with results rounded to the nearest $300 under a formula set by federal law.10Office of the Law Revision Counsel. 42 USC 430 – Adjustment of Contribution and Benefit Base The limit generally rises over time; it was $160,200 in 2023.
The cap applies to self-employed workers too. Once your net self-employment income (after the 92.35% adjustment) reaches $184,500, you stop owing the 12.4% Social Security portion. If you have both a job and a side business, your wages count first toward the cap, and only the remaining room is subject to self-employment Social Security tax.11Internal Revenue Service. Publication 15-A (2026), Employer’s Supplemental Tax Guide
Income That Isn’t Taxed for Social Security
The tax applies to wages and net self-employment earnings only. Interest, dividends, capital gains, and rental income aren’t subject to Social Security tax. Pension payments and annuity distributions are also excluded.12Social Security Administration. What Income Is Included in Your Social Security Record These may still owe regular income tax, but they don’t count toward the wage base and don’t add to your Social Security contributions.
How Social Security Fits Into FICA
Social Security tax is one piece of the Federal Insurance Contributions Act, or FICA. The other piece is Medicare, at 1.45% for the employee and 1.45% for the employer.11Internal Revenue Service. Publication 15-A (2026), Employer’s Supplemental Tax Guide Add the two together and most employees see 7.65% withheld (6.2% Social Security plus 1.45% Medicare). With the employer’s matching share included, 15.3% of your wages go to the two programs.
One important difference: Medicare has no wage base limit. The 1.45% comes out of every dollar you earn, no matter how high your income goes.
The Extra 0.9% for High Earners
If your wages pass $200,000 in a calendar year, your employer must withhold an additional 0.9% Medicare tax on every dollar above that amount, bringing Medicare withholding to 2.35% on those earnings.2Office of the Law Revision Counsel. 26 USC 3101 – Rate of Tax
The $200,000 withholding trigger doesn’t change with your filing status, but your actual liability does:
- Married filing jointly: 0.9% on combined wages and self-employment income above $250,000.
- Married filing separately: 0.9% on income above $125,000.
- All other filers: 0.9% on income above $200,000.
Because the withholding threshold doesn’t line up with every filing status, you may owe more when you file, or you may receive a credit. The reconciliation happens on Form 8959.13Internal Revenue Service. Topic No. 560, Additional Medicare Tax Only the employee pays this extra 0.9%; employers don’t match it.14Internal Revenue Service. Questions and Answers for the Additional Medicare Tax Self-employed workers owe the same 0.9% on self-employment income above the same filing-status thresholds, in addition to the 2.9% Medicare and 12.4% Social Security they already pay.5Office of the Law Revision Counsel. 26 USC 1401 – Rate of Tax
If Too Much Was Withheld
Working for a single employer and see deductions continue past the $184,500 wage base? Your employer is required to fix the error and refund the excess. If they won’t, you can file Form 843 with the IRS to claim it directly.15Internal Revenue Service. Topic No. 608, Excess Social Security and RRTA Tax Withheld
The more common case involves two or more employers in the same year. Each one withholds independently, with no way to know what the others have already taken. If your combined wages pass $184,500, the total withheld will exceed the $11,439 annual maximum. You claim the difference as a credit on your income tax return. Spouses filing jointly calculate any excess separately.
Penalties for Not Paying
Employers face steep consequences for failing to withhold and deposit Social Security taxes. A person responsible for collecting and paying over employment taxes who willfully fails to do so can be charged a penalty equal to 100% of the unpaid tax.16Office of the Law Revision Counsel. 26 USC 6672 – Failure to Collect and Pay Over Tax This penalty can apply personally, not just to the company.
Self-employed workers who miss quarterly estimated tax deadlines face interest-based underpayment penalties, calculated from each missed due date until the balance is paid.17Internal Revenue Service. Estimated Taxes The penalty can still apply for a shortfall in a given quarter even if you’re due a refund when you file your annual return.