OASDI Tax: What It Is and How It Affects Your Paycheck

What Is OASDI Tax?

If you look closely at your pay stub, you will see a deduction labeled "OASDI" or sometimes "Social Security." OASDI stands for Old-Age, Survivors, and Disability Insurance -- the formal name for the Social Security program. Combined with Medicare, OASDI taxes make up what most people know as FICA (Federal Insurance Contributions Act) taxes. Understanding how OASDI works, how much you pay, and what it funds is essential knowledge for every worker and especially for the self-employed.

What OASDI Funds

OASDI taxes fund three specific categories of Social Security benefits:

Old-Age Insurance -- Monthly retirement benefits for workers who have paid into the system and reached qualifying age. Full retirement age is 67 for people born after 1960.

Survivors Insurance -- Benefits paid to surviving spouses, children, and dependent family members when a covered worker dies.

Disability Insurance -- Monthly benefits for workers who become unable to work due to a qualifying disability before reaching retirement age.

These three programs together represent the largest social insurance program in the United States, providing benefits to over 70 million Americans.

OASDI Tax Rates in 2026

The OASDI tax rate is 12.4% of covered wages. This cost is split evenly between the employer and employee:

• Employee share: 6.2% withheld from each paycheck
• Employer share: 6.2% paid directly by the employer

Employees effectively pay 6.2%, which appears as a deduction on their pay stub. The employer's matching 6.2% does not appear on your paycheck -- it is a separate expense the employer pays.

The OASDI tax applies only up to the Social Security wage base -- the maximum amount of earnings subject to the tax. For 2026, the wage base is $176,100. Income above this threshold is not subject to OASDI tax, though it remains subject to Medicare tax.

Medicare Tax (HI Tax)

The companion to OASDI is the Medicare Hospital Insurance (HI) tax, also part of FICA. The Medicare tax rate is 2.9%, split evenly at 1.45% each for employer and employee.

Unlike OASDI, Medicare has no wage base ceiling -- the 2.9% applies to all earned income. High earners (those earning above $200,000 for single filers, $250,000 for married filing jointly) pay an additional 0.9% Additional Medicare Tax on wages above those thresholds.

Combined, OASDI plus Medicare = 15.3% total FICA tax (employer and employee combined), or 7.65% for each party.

OASDI Tax for Self-Employed Workers

Self-employed individuals pay both the employee and employer shares of OASDI and Medicare tax, making their total self-employment tax burden 15.3% (12.4% OASDI + 2.9% Medicare). This is calculated on Schedule SE and added to your income tax liability on Form 1040.

For example, on $80,000 of net self-employment income, the self-employment tax is approximately $11,304 (13.3% effective rate due to the self-employment income deduction calculation). This is a significant cost that self-employed workers must factor into their pricing and tax planning.

The one offset: self-employed workers can deduct half of their self-employment tax as an above-the-line adjustment on Form 1040, reducing their taxable income for income tax purposes (though not for self-employment tax purposes).

The OASDI wage base applies the same way for self-employed workers -- net self-employment income above $176,100 in 2026 is not subject to the 12.4% Social Security portion.

OASDI Tax on Your Pay Stub

Your pay stub shows OASDI or Social Security withholding as a separate line item distinct from federal income tax withholding. Over the course of a year, if you earn $80,000 as an employee, your OASDI withholding is $4,960 (6.2% $80,000), and your Medicare withholding is $1,160 (1.45% $80,000).

Your employer matches these exact amounts out of their own pocket -- so the full economic cost to employ you includes $6,120 in FICA taxes per year at that salary level, in addition to your gross wages.

Social Security Work Credits

OASDI contributions translate into work credits toward Social Security eligibility. In 2026, you earn one credit for every $1,730 in covered earnings, with a maximum of four credits per year. You need 40 credits (10 years of work) to qualify for full retirement benefits. Disability and survivors benefits require fewer credits, with the exact amount depending on your age.

Working as a gig worker, freelancer, or self-employed individual builds the same Social Security credits as traditional employment -- provided you accurately report and pay self-employment taxes. Underpaying or not filing Schedule SE reduces the credits you accumulate toward eventual benefits.

Track your self-employment income and estimated taxes using Eonebill, and consult the freelancer tax guide for complete guidance on managing your self-employment tax obligations. See also our overview of self-employed tax deductions and the 1099 tax calculator.

OASDI Tax and Retirement Planning for Self-Employed Workers

For self-employed workers, OASDI taxes serve a dual purpose: they are both a current expense and an investment in future benefits. Every dollar of Social Security tax you pay builds toward the retirement, disability, and survivors benefits you and your family may someday depend on.

Maximizing your benefit through consistent contributions

Social Security benefits at retirement are calculated based on your highest 35 years of covered earnings. If you have years with zero or very low reported income (perhaps years you worked off the books, had no self-employment income, or did not file), those zeros drag down your average -- reducing your eventual monthly benefit.

For self-employed workers, the implication is clear: report all income, file Schedule SE every year you have self-employment income, and pay the full self-employment tax. Each year of contributions strengthens your eventual benefit.

Social Security disability and survivors benefits

Beyond retirement, OASDI includes disability and survivors insurance. If you become disabled before retirement age, you may qualify for Social Security Disability Insurance (SSDI). If you die with eligible dependents, your family may receive survivors benefits. These protections have real value -- effectively a form of insurance built into every OASDI dollar you pay.

The wage base ceiling and high-income planning

For 2026, OASDI tax applies only to the first $176,100 of earnings. Income above this threshold is exempt from the 12.4% Social Security portion. For high earners -- particularly S-corp owners who pay themselves a salary above the wage base -- understanding this ceiling is part of tax planning. An S-corp salary at or near the wage base maximizes Social Security credits while limiting OASDI exposure on excess earnings taken as distributions.

Understanding Your Social Security Statement

The Social Security Administration (SSA) maintains a record of your covered earnings and provides an estimate of your eventual benefits. You can create a free account at ssa.gov to view your Social Security statement, which shows:

• Your year-by-year earnings history
• The credits you have accumulated
• Estimated retirement benefit at age 62, 67, and 70
• Estimated disability benefit
• Estimated survivors benefit for your family

Review this statement periodically to verify your earnings are being recorded correctly. Errors in your earnings record are more common than most people realize and can be corrected -- but only within a limited time window.

For ongoing income tracking and financial management as a self-employed professional, use Eonebill and the expense tracker. See the freelancer tax guide for complete self-employment tax planning guidance.

OASDI for Self-Employed Workers: A Deeper Dive

The self-employment tax mechanism is more nuanced than it appears on a pay stub. Here is how it actually works for freelancers and independent contractors:

The employer/employee split: When you are self-employed, you pay both halves of OASDI -- the 6.2% employee portion and the 6.2% employer portion, for 12.4% total. This is because from the Social Security Administration's perspective, you are both the employer and the employee.

The deduction for the employer half: The IRS allows you to deduct 50% of your self-employment tax (the "employer half") from your gross income before calculating your income tax. This deduction appears on Schedule 1, not Schedule C. It partially offsets the double burden. On $50,000 of net self-employment income, the SE tax is about $7,065, and you can deduct roughly $3,533 from your income tax calculation.

The Social Security earnings credit: OASDI payments earn you Social Security credits. You need 40 lifetime credits (10 years of work) to qualify for retirement benefits. In 2026, you earn one credit for every $1,730 of earnings (up to 4 credits per year). Consistent self-employment income that generates OASDI payments builds toward your retirement benefit -- something W-2 workers take for granted but self-employed workers must consciously track.

Planning Around the OASDI Wage Base

High-earning freelancers who expect to exceed the wage base ($176,100 in 2026) mid-year can adjust their quarterly estimated tax payments in the second half of the year once they have exceeded the cap. The full SE tax applies only to income up to the wage base; Medicare's 2.9% continues with no cap (and an additional 0.9% surcharge above $200,000 for single filers). Track your cumulative net self-employment income against the wage base to optimize quarterly payments. Use the 1099 tax calculator to model your OASDI and Medicare obligations at different income levels.