OASDI withholding on your paycheck is the Social Security tax. It stands for Old-Age, Survivors, and Disability Insurance, and in 2026 your employer takes 6.2% of your gross wages on every check until your year-to-date earnings reach $184,500.1Social Security Administration. Contribution and Benefit Base Some stubs label the line “OASDI,” others say “Social Security” or “FICA-SS.” Same deduction.
What the Money Funds
The name is literal. Old-Age benefits go to retirees. Survivors benefits go to the spouse, children, or other dependents of a worker who dies. Disability Insurance covers workers whose condition prevents them from earning a living. Your withholding pays today’s beneficiaries, and future workers’ withholding will pay yours. It’s not sitting in a personal account with your name on it.
How Much Comes Out
The employee rate is 6.2% of your gross taxable wages, and your employer pays a matching 6.2% that never appears on your stub, for a combined 12.4%.2Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates The rate is set by federal law. It doesn’t change with your W-4 elections or filing status.3Social Security Administration. FICA and SECA Tax Rates
One thing catches people off guard when they compare their stub to their gross pay: pre-tax 401(k) and 403(b) contributions reduce your federal income tax but do not reduce your OASDI wages. Social Security tax is calculated on your gross before those retirement deferrals come out.4Internal Revenue Service. Retirement Plan FAQs Regarding Contributions Earn $5,000 in a pay period and defer $500 into your 401(k), and OASDI still comes out of the full $5,000.
The 2026 Wage Base Limit
OASDI only applies to a fixed amount of earnings each year. For 2026, that ceiling is $184,500.1Social Security Administration. Contribution and Benefit Base Once your cumulative gross pay for the calendar year crosses that line, your employer stops withholding the 6.2%. Your take-home pay jumps for the rest of the year, and withholding resets on January 1.
The most an employee pays in OASDI tax for 2026 is $11,439, which is 6.2% of $184,500. Your employer pays an identical $11,439.1Social Security Administration. Contribution and Benefit Base The Social Security Administration adjusts the limit annually based on the national average wage index, so it tends to rise. The 2025 limit was $176,100.5Social Security Administration. 2025 Cost-of-Living Adjustment (COLA) Fact Sheet
When You Have Two Jobs
Each employer tracks your withholding on its own. If you work two jobs and your combined wages exceed $184,500, both employers will keep withholding OASDI on their respective wages, and your total can push past the $11,439 cap. You recover the excess by claiming a credit on your federal income tax return.6Internal Revenue Service. Topic No. 608, Excess Social Security and RRTA Tax Withheld Employers aren’t required to refund the overpayment directly, so filing is the only way to get that money back.
OASDI Versus the Medicare Line
Your stub likely shows a second FICA deduction for Medicare, sometimes labeled “HI” for Hospital Insurance. The employee Medicare rate is 1.45%, matched by your employer.2Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates Together with the 6.2% OASDI rate, your total FICA withholding is 7.65% of covered wages.
The important difference is that Medicare has no wage base limit. OASDI stops at $184,500; Medicare’s 1.45% applies to every dollar you earn. Wages above $200,000 in a calendar year also carry an additional 0.9% Medicare surtax, which the employer withholds regardless of your filing status and does not match.7Internal Revenue Service. Topic No. 560, Additional Medicare Tax
Who Doesn’t Pay OASDI
Most workers pay it with no way around it. A few narrow categories are excluded:
- Students employed by their own school, if enrolled at least half-time and not classified as a professional employee eligible for benefits like vacation, retirement plan participation, or paid holidays.8Internal Revenue Service. Student FICA Exception
- Members of recognized religious groups (most commonly Old Order Amish and some Mennonite congregations) that have provided for their dependents since at least December 31, 1950, and that conscientiously oppose insurance benefits. Applying uses IRS Form 4029 and permanently waives all Social Security and Medicare benefits.9Internal Revenue Service. Form 4029, Application for Exemption From Social Security and Medicare Taxes and Waiver of Benefits
- Nonresident alien students in F-1, J-1, or M-1 status who have been in the U.S. fewer than five calendar years.10Internal Revenue Service. Foreign Student Liability for Social Security and Medicare Taxes
- Certain state and local government employees covered by a qualifying public retirement system and not part of a Section 218 agreement, which most often affects some police officers, firefighters, and workers in temporary or fee-basis positions.11Social Security Administration. Social Security Act 218 – Voluntary Agreements for Coverage of State and Local Employees
If none of those apply to you and OASDI is on your stub, the withholding is correct.
What You Get for Paying It
Every year of OASDI taxes builds Social Security credits, formally called Quarters of Coverage. In 2026, you earn one credit for every $1,890 in covered earnings, up to four per year, so $7,560 in covered wages during the year earns the full four.12Social Security Administration. Quarter of Coverage You need 40 credits, roughly ten years of work, to qualify for retirement benefits.13Social Security Administration. Social Security Credits and Benefit Eligibility
Your eventual benefit is based on your highest 35 years of OASDI-taxed earnings, adjusted for wage inflation, and paid in full at your full retirement age (67 for anyone born in 1960 or later). Claiming earlier reduces the check; waiting until 70 increases it.14Social Security Administration. Retirement Age and Benefit Reduction Earnings above each year’s wage base don’t count toward the calculation because they weren’t taxed. Benefits already in pay receive an annual cost-of-living adjustment; for 2026, that was 2.8%.15Social Security Administration. 2026 Cost-of-Living Adjustment (COLA) Fact Sheet