OASDI stands for Old-Age, Survivors, and Disability Insurance — the formal name for the federal program most people call Social Security. If you’ve seen “OASDI” on your pay stub, that line represents the 6.2% of your wages withheld to fund retirement checks, survivor payments for families who lose a wage earner, and disability income for workers who can no longer hold a job. In 2026, this tax applies to earnings up to $184,500.1Social Security Administration. Contribution and Benefit Base
What the Three Letters Actually Cover
The program’s name spells out what it does. Each letter points to a separate type of insurance, and each pays out under different conditions.
Old-Age (Retirement) Benefits
Workers who paid in long enough can start collecting monthly retirement checks as early as age 62, though filing that early means a permanently smaller payment. The benefit formula is weighted so lower earners get back a higher percentage of what they earned during their working years. In 2026, the maximum monthly benefit for someone retiring at full retirement age is $4,152.2Social Security Administration. 2026 Cost-of-Living Adjustment (COLA) Fact Sheet
Survivors Insurance
When a covered worker dies, their surviving spouse, dependent children, and in some cases dependent parents can receive monthly payments based on the deceased worker’s earnings record.3Social Security Administration. Who Can Get Survivor Benefits The worker doesn’t need to have reached retirement age for their family to qualify. What matters is that they earned enough work credits before death.
Disability Insurance
Workers who develop a severe medical condition can receive monthly income through the disability side of OASDI. The bar is high: the condition must prevent you from performing any substantial work, and it must be expected to last at least 12 months or result in death.4Social Security Administration. 20 CFR 404.1505 – Basic Definition of Disability This is not short-term disability coverage. It’s meant for conditions that indefinitely take someone out of the workforce.
How Much You Pay
The tax is split between you and your employer. Each side pays 6.2% of your gross wages, for a combined 12.4%.5Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates OASDI is one piece of FICA (the Federal Insurance Contributions Act), which also includes a separate 1.45% Medicare tax on each side. Your employer handles the withholding and sends both shares to the Treasury.
You only pay OASDI on earnings up to the annual wage base limit. For 2026, that cap is $184,500.1Social Security Administration. Contribution and Benefit Base Once your year-to-date earnings hit that figure, OASDI withholding stops until January. The cap adjusts each year based on changes in average national wages.6Social Security Administration. Contribution and Benefit Base Determination Any wages above the cap are still subject to Medicare tax, which has no ceiling.
The most any employee will pay in OASDI tax in 2026 is $11,439, or 6.2% of the wage base.
Self-employed workers pay both halves themselves — the full 12.4% — because there’s no employer to split the cost with.1Social Security Administration. Contribution and Benefit Base To soften that, you can deduct the employer-equivalent portion (half the self-employment tax) when calculating adjusted gross income.7Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes) The deduction lowers your income tax bill but not the self-employment tax itself.
Who Pays and Who Doesn’t
Nearly everyone who works in the United States pays into OASDI. W-2 employees see it withheld automatically. Self-employed workers who earn $400 or more owe it on their tax return. A few narrow exceptions exist.
Some state and local government employees are exempt if their employer participates in a qualifying public pension system instead of Social Security. These arrangements, known as Section 218 agreements, let government entities opt their workers out of OASDI in exchange for providing equivalent retirement coverage through their own pension plans.8Social Security Administration. Section 218 Agreements Workers covered by these plans don’t pay the 6.2% tax and don’t earn Social Security credits for that employment.
Students employed by the college or university where they’re enrolled and attending classes are also exempt from FICA withholding, as long as the work is connected to their educational experience rather than purely professional employment.9Internal Revenue Service. Student Exception to FICA Tax The exemption disappears once the student’s primary relationship with the school shifts from education to employment.
What You Get for Paying In
Paying OASDI taxes earns work credits, and credits determine whether you qualify for benefits. You can earn up to four credits per year. In 2026, one credit takes $1,890 in covered earnings, so $7,560 in a year maxes out your credits.10Social Security Administration. Quarter of Coverage That threshold rises each year with average wages.
Retirement benefits require 40 credits, which works out to roughly ten years of work.11Social Security Administration. Social Security Credits and Benefit Eligibility Once earned, credits stay on your record permanently. Switch careers, take years off, leave the workforce — you don’t lose them.
Disability and survivor benefits use a sliding scale that accounts for younger workers who haven’t had decades to accumulate credits. A worker under age 24, for example, may qualify for disability benefits with just six credits earned in the three years before the disability began.12Social Security Administration. How You Earn Credits Families aren’t left unprotected simply because a tragedy strikes early in a working life.
How the Benefit Is Calculated
The Social Security Administration uses your highest 35 years of earnings to calculate a retirement benefit.13Social Security Administration. Social Security Benefit Amounts Each year’s earnings are first adjusted for wage inflation, and the top 35 are averaged into a monthly figure called Average Indexed Monthly Earnings (AIME). If you worked fewer than 35 years, zeros fill the gaps, which is why missing years drag a benefit down noticeably.
Your AIME then runs through a progressive formula. For workers first becoming eligible in 2026, the calculation is:14Social Security Administration. Benefit Formula Bend Points
- 90% of the first $1,286 of AIME
- 32% of AIME between $1,286 and $7,749
- 15% of AIME above $7,749
The result is your Primary Insurance Amount, or PIA — the monthly benefit at full retirement age. Full retirement age is 67 for anyone born in 1960 or later.15Social Security Administration. Benefits Planner – Retirement Age Calculator Claiming at 62 shrinks the check by about 30% compared to waiting until 67, and the reduction is permanent.16Social Security Administration. Retirement Age and Benefit Reduction Delaying past full retirement age adds 8% per year up to age 70, after which there’s no further increase.17Social Security Administration. Benefits Planner – Delayed Retirement Credits
The weighting on that formula is the reason someone earning $40,000 a year replaces a larger share of their income through Social Security than someone earning $150,000. OASDI is designed as insurance, not a savings account, and the payout reflects that.