OASDI is the payroll tax that funds Social Security and Medicare

OASDI stands for Old-Age, Survivors, and Disability Insurance. It is the 6.2% payroll tax withheld from your wages to fund Social Security benefits — retirement, survivor benefits for your family if you die, and disability benefits if you become unable to work. Your employer pays a matching 6.2%, so the total contribution is 12.4% of your wages, though you only see the employee half deducted from your check.

OASDI is separate from Medicare tax (which is 1.45% on your wages) and from income tax withholding. When you see your pay stub, OASDI appears as a line item, usually labeled "Social Security" or "OASDI." The tax applies only to wages up to an annual cap — that cap changes each year based on wage growth. In 2024, the cap is $168,600, meaning you stop paying OASDI tax once your wages reach that amount in a calendar year.

If you are self-employed, you pay both the employee and employer portions yourself (12.4% total) through self-employment tax on Schedule SE. That amount is then deducted from your income when you calculate your federal income tax.

Key Takeaways

  • OASDI tax is 6.2% of your wages (your employer matches it), and it funds Social Security retirement, survivor, and disability benefits.
  • The tax applies only to wages below an annual cap, which was $168,600 in 2024 and increases each year.
  • Self-employed people pay the full 12.4% (both employee and employer portions) on Schedule SE.
  • OASDI is withheld automatically from paychecks and is separate from Medicare tax and federal income tax withholding.
  • You cannot opt out of OASDI tax; it is mandatory for all wage earners and self-employed individuals.

How the OASDI wage cap affects your tax burden

Because OASDI tax has an annual wage cap, high earners pay a smaller percentage of their total income in OASDI tax than lower-wage workers do. If you earn $200,000 in a year, you pay OASDI tax only on the first $168,600 (the 2024 cap), not on the remaining $31,400. A person earning $50,000 pays OASDI tax on all $50,000.

The cap resets each January 1st. If you change jobs mid-year and your combined wages from both employers exceed the cap, you may have overpaid OASDI tax. You can claim a credit for the overpayment when you file your federal income tax return — you do not have to wait for a refund or contact Social Security. The IRS will calculate it automatically if you report all your W-2 income.

If you are self-employed, you calculate OASDI tax on your net self-employment income (after deducting half of your self-employment tax itself), and the same wage cap applies. Once your net self-employment income reaches the cap, you stop paying OASDI tax for that year.

OASDI tax versus Medicare tax and income tax

OASDI, Medicare, and federal income tax are three separate withholdings on your paycheck, and they fund different programs. OASDI (6.2%) funds Social Security. Medicare tax (1.45% on all wages, with no cap) funds the Medicare hospital insurance program. Federal income tax withholding is based on your W-4 form and funds general government operations.

Additionally, if your income exceeds certain thresholds, you may owe an extra 0.9% Medicare tax on wages above those thresholds. This is separate from the standard 1.45% Medicare tax and has no cap. OASDI, by contrast, stops at the annual wage cap.

On your pay stub, each withholding is listed separately so you can see exactly how much goes to each program. When you file your tax return, OASDI and Medicare taxes are already withheld and do not change — they are not adjusted based on your filing status or deductions the way income tax can be.

What happens if you do not pay OASDI tax

You cannot legally avoid OASDI tax if you are a wage earner or self-employed. It is mandatory. If an employer fails to withhold OASDI tax from your paycheck, you are still liable for the tax, and the IRS will pursue collection from you, the employer, or both.

The only people exempt from OASDI tax are certain government employees hired before specific dates (such as some federal employees with their own pension systems) and nonresident aliens on certain visa types. If you are a U.S. citizen or permanent resident working in the United States, you owe OASDI tax on your wages.

If you work "under the table" and do not report income, you are breaking tax law and also building no Social Security record. This affects your future may be able to access for retirement, survivor, and disability benefits. The Social Security Administration tracks your earnings record based on the W-2 forms and self-employment tax returns you file.

OASDI tax and your Social Security benefit calculation

Your OASDI tax payments create a record with the Social Security Administration. The amount you pay does not directly determine your benefit amount, but your earnings record does. Social Security calculates your benefit based on your 35 highest-earning years (adjusted for inflation). The more you earn and pay OASDI tax on, the higher your eventual benefit.

You can view your earnings record and benefit estimate by creating an account on ssa.gov. The Social Security Administration sends you a statement (called a "Social Security Statement") that shows your earnings history and an estimate of your retirement benefit at full retirement age, as well as your survivor and disability benefit amounts.

If you have gaps in your earnings record — years when you did not work or earned very little — those years count as zeros in the calculation. Working longer and earning more can increase your benefit, but only if those years replace lower-earning years in your top 35.

Self-employed OASDI tax and Schedule SE

If you are self-employed, you report OASDI tax on Schedule SE (Self-Employment Tax) when you file your federal income tax return. You calculate your net self-employment income (your business income minus business expenses), multiply it by 92.35%, and then explore the 12.4% OASDI rate to that amount.

The 92.35% figure accounts for the fact that self-employed people pay both the employee and employer portions of the tax. You then deduct half of your self-employment tax from your income when calculating your adjusted gross income (AGI), which lowers your income tax liability.

Self-employed people must pay estimated tax quarterly (using Form 1040-ES) if they expect to owe $1,000 or more in federal income and self-employment tax for the year. OASDI tax is included in that calculation. If you do not pay quarterly and owe a large amount at tax time, you may face an underpayment penalty.

OASDI tax changes and future considerations

The OASDI wage cap increases each year based on the National Average Wage Index. In recent years it has risen by roughly $1,000 to $3,000 annually, though the exact increase varies. The Social Security Administration announces the new cap in October for the following year.

The OASDI tax rate (6.2% for employees, 12.4% total) has been the same since 1990. However, Social Security's trust fund faces long-term solvency challenges. If Congress does not act, the trust fund is projected to be depleted sometime in the 2030s, after which incoming OASDI tax revenue would cover only about 80% of scheduled benefits. This is a policy question, not a tax question, but it may affect future benefit amounts or tax rates.

For now, OASDI tax remains mandatory and unchanged. Staying informed about your earnings record and benefit estimate helps you plan for retirement and understand how your tax contributions translate into future benefits.

Frequently Asked Questions

Can I deduct OASDI tax from my income taxes?

No, not directly. OASDI tax is withheld from your paycheck and is not deductible as an itemized deduction. However, if you are self-employed, you can deduct half of your self-employment tax (which includes OASDI) from your income when calculating your adjusted gross income. This lowers your taxable income but does not reduce the OASDI tax itself.

What if I worked in multiple states during the year?

OASDI tax is federal, not state-based, so it does not matter which states you worked in. You pay 6.2% on all wages up to the annual cap, regardless of location. Some states have their own payroll taxes (like state disability insurance), but those are separate from OASDI.

Do I pay OASDI tax on bonuses and commissions?

Yes. OASDI tax applies to all wages, including bonuses, commissions, overtime pay, and most other forms of compensation. The only limit is the annual wage cap. Once your total wages (from all sources) reach the cap, no more OASDI tax is withheld that year.

What happens to OASDI tax if I become disabled before retirement?

Your OASDI tax contributions fund disability benefits as well as retirement benefits. If you become unable to work due to a medical condition expected to last at least 12 months, you may be able to claim Social Security Disability Insurance (SSDI). Your earnings record from OASDI tax payments helps establish your may be able to access and benefit amount.

Do I pay OASDI tax on income from investments or rental property?

No. OASDI tax applies only to wages from employment and net self-employment income from a business you operate. Investment income, rental income, capital gains, and interest do not trigger OASDI tax. However, if you are self-employed and have business income, you pay OASDI tax on that business income.