OASDI Tax: What It Is, How Much You Pay, and What It Means for Your Paycheck

OASDI tax is the Social Security payroll tax. OASDI stands for Old-Age, Survivors, and Disability Insurance. In 2026, employees pay 6.2% of wages up to $184,500, and employers match it with another 6.2%, for a combined 12.4%. The maximum employee OASDI tax for 2026 is $11,439.

Last updated: October 15, 2026 | Reviewed by: Dev Kothari, CPA | Sources: Social Security Administration, IRS

If you’ve ever looked closely at your pay stub, you’ve probably spotted a line labeled OASDI, Fed OASDI/EE, or FICA-OASDI and wondered why money is leaving your paycheck before you see it. You’re not alone. It’s one of the most-searched deduction codes on any pay stub, and for business owners running payroll management in-house, getting it wrong can trigger real IRS penalties.

Below, we break down what OASDI tax is, how the rate and wage limit work, how to calculate it, who pays it, whether you can get any of it back, and how to reduce it legally.

What does OASDI stand for?

OASDI stands for Old-Age, Survivors, and Disability Insurance. It’s the formal, legal name for the program most people call Social Security. If you’re asking “what does OASDI stand for” or “what is OASDI on my paycheck,” the short answer is that it’s your Social Security contribution, labeled with its official government name.

What is OASDI tax?

OASDI tax is a mandatory federal payroll tax that funds the Social Security program. It’s collected under the Federal Insurance Contributions Act (FICA), the same law that authorizes the Medicare tax. Together, OASDI and Medicare make up your FICA withholding.

The money doesn’t sit in a personal account with your name on it. It flows into two federal trust funds, the Old-Age and Survivors Insurance (OASI) Trust Fund and the Disability Insurance (DI) Trust Fund. The Social Security Administration uses them to pay:

• Retirement benefits to workers who’ve reached eligibility age
• Survivor benefits to the spouses, children, or dependent parents of workers who’ve died
• Disability benefits to workers who can no longer work because of a qualifying disability

Your OASDI tax also earns you work credits. You generally need 40 credits (about 10 years of work) to qualify for retirement benefits, and your future benefit is based on your lifetime earnings record.

In plain English, OASDI tax is what you and your employer pay today so Social Security can pay benefits to retirees, disabled workers, and survivors, including, eventually, you.

Where OASDI shows up on your paycheck

Payroll software doesn’t always label it the same way. Depending on your provider, the same deduction might appear as:

• OASDI
• Fed OASDI/EE. “Fed” means federal, and “/EE” means “employee,” so it’s your share (as opposed to “/ER,” the employer’s share)
• FICA – OASDI or FICA OASDI
• Social Security or SS Tax
• OASDI/Medicare (sometimes grouped, though they’re two separate taxes)

All of these refer to the same 6.2% withholding. Your total OASDI withholding for the year also appears in Box 4 of your W-2 form, which is worth checking closely if you held more than one job.

For employers, keeping this line accurate on every pay run matters. Miscalculating OASDI is a common trigger for missed IRS payroll tax deadlines and the penalties that follow.

OASDI tax rate: how much do you pay?

The OASDI tax rate is 6.2% of gross wages for employees. Your employer pays a matching 6.2%, for a combined 12.4%. The rate has been the same since 1990.

Add the 1.45% Medicare tax each side pays, and total FICA is 15.3%: 7.65% from you and 7.65% from your employer. See the IRS’s breakdown of Social Security and Medicare taxes for the rules employers follow.

OASDI tax limit (wage base) for 2026

OASDI tax doesn’t apply to unlimited income. It applies only up to a yearly cap called the wage base limit (or taxable maximum). Once your year-to-date wages pass that number, OASDI withholding stops for the rest of the calendar year. Medicare tax keeps applying to every dollar, with no cap.

The 2026 maximum is $520.80 higher than 2025 for each worker. The SSA adjusts the limit every year based on the National Average Wage Index. You can see the full history on the SSA’s wage base page.

If you earn less than the wage base, OASDI is withheld from every paycheck all year. If you earn more, withholding stops once you hit the cap, and you’ll usually notice a jump in take-home pay later in the year. Payroll teams and bookkeeping staff need to track this threshold per employee, per employer, which is a common error source for businesses running payroll manually.

How to calculate OASDI tax

Formula: OASDI tax = taxable wages (up to $184,500) × 6.2%

Example 1: under the limit. An employee earns $60,000 in 2026. $60,000 × 6.2% = $3,720. The employer pays another $3,720.

Example 2: over the limit. An employee earns $250,000. Only the first $184,500 is taxed: $184,500 × 6.2% = $11,439. The remaining $65,500 has no OASDI tax. The employer also pays $11,439.

Example 3: per paycheck. A biweekly paycheck of $2,500 gross: $2,500 × 6.2% = $155 withheld.

Example 4: self-employed. Net self-employment earnings are $80,000. First multiply by 92.35%: $80,000 × 92.35% = $73,880. Then apply 12.4%: $73,880 × 12.4% = $9,161.12 for the OASDI portion. (Medicare is calculated separately.)

Wages from a W-2 job count toward the same $184,500 limit as your self-employment earnings.

Who has to pay OASDI tax?

Yes, OASDI tax is mandatory for the vast majority of U.S. workers. Federal law requires employees, employers, and self-employed individuals to contribute, up to the annual wage limit.

Groups that are generally exempt include:

1. Certain religious sect members. Followers of a recognized religious group (such as the Amish or some Mennonite communities) that opposes accepting Social Security benefits can apply for exemption using IRS Form 4029. This applies to both employees and the self-employed.
2. Certain non-resident aliens, including some students, scholars, and foreign government employees on specific visa types (such as F-1, J-1, M-1, or Q) doing work tied to their visa purpose.
3. Some student employees, when they work for the school they attend and the work is related to their studies.
4. Very low-earning self-employed individuals with less than $400 per year in net self-employment earnings.
5. Some state and local government employees. Public employees in positions not covered by Social Security under their state’s agreement don’t pay OASDI tax (they still pay Medicare tax).

Outside these narrow exceptions, if you receive a regular paycheck or have self-employment income above the threshold, OASDI applies to you. Freelancers and independent contractors who receive 1099 income pay OASDI through self-employment tax instead of payroll withholding.

For employers, correct worker classification and exemption handling is part of broader payroll compliance. Businesses that use outsourced payroll providers typically see fewer withholding errors and fewer IRS notices than those handling it entirely in-house.

Self-employed OASDI tax (SECA)

Self-employed people pay both halves, 12.4%, through self-employment tax. You calculate it on Schedule SE using 92.35% of your net self-employment earnings, up to the same $184,500 wage base. You can then deduct half of your total self-employment tax (OASDI plus Medicare) on Form 1040 as an adjustment to income. Net earnings under $400 are not subject to the tax.

Calculating this correctly alongside your estimated payments is exactly the kind of detail our tax planning and advisory team helps self-employed clients get right each year.

How employers report and deposit OASDI tax

Employers must withhold the employee’s 6.2%, add a matching 6.2%, and deposit both on the IRS schedule (monthly or semiweekly). The tax is reported quarterly on Form 941, or annually on Form 944 for very small employers. At year-end, wages subject to OASDI appear in W-2 Box 3, and the tax withheld appears in Box 4.

Bonuses, commissions, and overtime are all subject to OASDI tax until the employee reaches the wage base.

Tracking wage bases, deposit deadlines, and year-end reporting for every employee adds up quickly. That’s why many growing businesses hand it to a payroll management team.

Is OASDI tax deductible?

For most W-2 employees, OASDI tax is not deductible on your federal return. It’s withheld automatically and isn’t itemized.

Self-employed individuals get a partial break. Because you pay both the employee and employer share through SECA, the IRS lets you deduct half of the self-employment tax you paid as an adjustment to income. It doesn’t eliminate the tax, but it does reduce your taxable income.

Can you get OASDI tax back?

In most cases, no. It isn’t refunded like income tax withholding. There is one common exception.

If you had two or more employers and your combined wages exceeded the annual wage base, each employer may have withheld OASDI independently, since none knew about your other job. You can claim the excess on Schedule 3 (Form 1040) when you file your federal return.

If a single employer withheld too much, you can’t claim it on your return. Ask your employer to correct it and refund you. Employers fix this using Form 941-X.

Not sure whether you overpaid? Our individual tax returns team can review your W-2s. Businesses that see repeated over- or underpayment across employees often benefit from a broader tax withholding review instead of fixing it one return at a time.

Can you reduce OASDI tax?

OASDI tax is mandatory, but some pay arrangements legally reduce the wages it applies to:

• Section 125 cafeteria plan benefits, such as pre-tax health insurance premiums, FSAs, and payroll HSA contributions, are generally exempt from FICA.
• Qualified commuter benefits are also generally exempt, up to the annual limits.
• S corporation owners pay OASDI only on W-2 salary, not distributions. The IRS requires that salary to be reasonable for the work performed.

Note that traditional 401(k) contributions lower your income tax but do not reduce OASDI wages.

Every situation is different, so talk to a CPA before changing how you pay yourself or your employees. Our tax planning and advisory team can review your setup.

OASDI vs. Medicare vs. FICA

These terms get used interchangeably, but they’re not the same:

OASDI is the official name for Social Security tax. If you’re curious how recent legislation affects retirees, we also covered the new $6,000 senior deduction in a separate guide.

When did OASDI tax start?

OASDI traces back to the Social Security Act of 1935, signed by President Franklin D. Roosevelt as part of the New Deal. Payroll tax collection began in January 1937 at 1% for employees and 1% for employers, a 2% combined rate. The first monthly Social Security benefit check, for $22.54, went out in January 1940. The rate rose gradually over the decades and reached today’s 6.2% each (12.4% combined) in 1990, where it has stayed since. You can view the full historical wage base and rate table on the SSA’s website.