What Social Security tax is and how much comes out of your paycheck

Social Security tax is a federal payroll tax that funds the Social Security program. If you work as an employee, your employer withholds 6.2% of your gross wages up to a yearly earnings cap. Your employer also pays a matching 6.2% on your behalf — that 12.4% combined is what funds benefits for retirees, disabled workers, and survivors.

The earnings cap changes each year. In 2024, you pay Social Security tax only on income up to $168,600. Once your wages exceed that amount in a calendar year, no more Social Security tax is withheld from your paychecks for the rest of that year. This cap is adjusted annually based on national wage trends.

If you are self-employed, you pay both the employee and employer portions yourself — 15.2% total — though you can deduct half of it as a business expense on your tax return. The same yearly earnings cap applies.

Key Takeaways

  • Employees pay 6.2% of wages up to the yearly earnings cap; employers pay a matching 6.2%.
  • The earnings cap for 2024 is $168,600 and increases each year based on wage growth.
  • Once you reach the cap in a given year, no more Social Security tax is withheld from your remaining paychecks that year.
  • Self-employed workers pay the full 15.2% (both employee and employer portions) on net self-employment income.
  • Social Security tax funds current benefits for retirees, disabled workers, and survivors of deceased workers.

How the earnings cap affects what you pay

The yearly earnings cap means higher earners pay a smaller percentage of total income in Social Security tax. A person earning $200,000 pays the tax on only $168,600 of that income, while someone earning $80,000 pays on all $80,000. This is why Social Security tax is sometimes called a regressive tax — it takes a larger share from lower earners.

The cap resets on January 1 each year. If you change jobs mid-year, each employer withholds based on what you earn at that job alone, not your total income across all employers. This can result in overpayment if your combined earnings exceed the cap. You can claim a refund of the excess when you file your tax return.

What happens if you overpay Social Security tax

Overpayment occurs when you work for multiple employers in the same year and your combined wages exceed the earnings cap. Each employer withholds 6.2% up to the cap as if you only work for them, so the total withheld can exceed what you legally owe.

You cannot get a refund directly from your employer or the Social Security Administration. Instead, you report the overpayment when you file your federal income tax return. The IRS will refund the excess as part of your overall tax refund or apply it to taxes owed. You need to know your total wages from all employers to calculate the overpayment correctly.

Self-employed workers and Social Security tax

If you are self-employed, you pay Social Security tax through the self-employment tax calculation on Schedule SE of your tax return. You pay 15.2% on 92.35% of your net self-employment income — the 92.35% figure accounts for the employer-side portion you would normally not pay yourself.

The same yearly earnings cap applies. For 2024, you pay self-employment tax only on net self-employment income up to $168,600. If your business income exceeds that, the excess is not subject to Social Security tax, though it may still be subject to Medicare tax (which has no cap).

You can deduct half of your self-employment tax as an adjustment to income on your tax return, which reduces your taxable income. This deduction partially offsets the fact that you pay both the employee and employer portions.

The difference between Social Security tax and Medicare tax

Social Security tax and Medicare tax are separate payroll taxes that appear on your pay stub. Social Security tax is 6.2% (employee) with an earnings cap. Medicare tax is 1.45% (employee) with no earnings cap — you pay it on all wages no matter how much you earn.

Higher earners also pay an additional 0.9% Medicare tax on wages above $200,000 (single filers) or $250,000 (married filing jointly). This additional tax has no employer match and was added under the Affordable Care Act. Together, Social Security and Medicare taxes are often called FICA taxes (Federal Insurance Contributions Act).

How Social Security tax connects to your future benefits

Social Security tax you pay now does not go into a personal account for you. Instead, it funds current benefits for people already receiving Social Security. Your own future benefits are based on your earnings record — specifically, your 35 highest-earning years of work.

To receive Social Security retirement benefits, you must have earned at least 40 work credits, which is roughly 10 years of covered employment. The amount of your monthly benefit depends on your age when you start and your average earnings over those 35 years. The Social Security Administration maintains a record of your earnings and credits based on the taxes you and your employers pay.

Frequently Asked Questions

Why is there an earnings cap on Social Security tax but not Medicare tax?

Social Security was designed as an insurance program with a wage-replacement benefit — the benefit formula is weighted to replace a higher percentage of lower earners' income. The cap reflects this design. Medicare is structured differently and has no cap, so higher earners pay Medicare tax on all wages.

If I work part-time and earn below the cap, do I still pay Social Security tax?

Yes. Social Security tax applies to all wages, regardless of how much you earn. There is no minimum earnings threshold. Even if you earn $5,000 in a year, you pay 6.2% Social Security tax on that amount (and your employer pays 6.2% as well).

Can I opt out of paying Social Security tax?

No. Social Security tax is mandatory for all employees and self-employed workers in the United States. The only exceptions are certain government employees hired before specific dates and some religious groups that have received an exemption from the IRS, which is rare and requires a formal process.

What if I did not work enough years to earn 40 credits?

You will not receive Social Security retirement benefits based on your own work record. However, you may be able to receive benefits as a spouse or survivor of someone who did earn 40 credits, depending on your age and relationship to that worker.

Does Social Security tax apply to tips and bonuses?

Yes. Tips and bonuses are considered wages and are subject to Social Security tax. Your employer should include them in your gross wages for payroll tax purposes. If you receive cash tips not reported to your employer, you are still required to report them on your tax return and pay Social Security tax on them.