What Is the Social Security Tax?

Social Security tax is the tax levied on both employers and employees to fund the Social Security program in the U.S. Social Security tax is collected in the form of a payroll tax mandated by the Federal Insurance Contributions Act (FICA) or a self-employment tax mandated by the Self-Employed Contributions Act (SECA).

The Social Security tax pays for the retirement, disability, and survivorship benefits that millions of Americans receive each year under the Old-Age, Survivors, and Disability Insurance (OASDI) Program—the official name for Social Security.

Key Takeaways

  • Social Security taxes fund the retirement, disability, and survivorship benefits that millions of Americans receive each year from the Social Security Administration.
  • In 2021, the Social Security tax rate is 12.4%, divided evenly between employers and employees, on a maximum wage base of $142,800.
  • Self-employed individuals pay the employer and employee portions of Social Security tax, but only on 92.35% of net business earnings.
  • Certain groups, including some nonresident aliens and members of religious groups with specific views, are exempt from paying Social Security tax.

How the Social Security Tax Works

The Social Security tax is applied to income earned by employees and self-employed taxpayers. Employers usually withhold this tax from employees’ paychecks and forward it to the government. The funds collected from employees for Social Security are not put into a trust for the individual employee currently paying into the fund, but rather are used to pay existing older people in a "pay-as-you-go" system.

Social Security tax is also collected to support individuals who are entitled to survivorship benefits—benefits paid to a surviving spouse upon the death of a spouse or to a dependent child upon the death of a parent.

As of 2021, the Social Security tax rate is 12.4%. Half of the tax, or 6.2%, is paid by the employer, and the employee is responsible for paying the other half. %. The Social Security tax rate is assessed on all types of income earned by an employee, including salaries, wages, and bonuses. However, there is an income limit to which the tax rate is applied. For 2021, the Social Security tax is taken from income up to an annual limit of $142,800; any amount earned above $142,800 is not subject to Social Security tax.


The base wage level limit for Social Security taxes in 2022. Any earnings above $147,000 are not subject to withholdings for Social Security.

Social Security Tax for the Self-Employed

Social Security tax is also taken from the earnings of the self-employed. Since the Internal Revenue Service (IRS) considers a self-employed individual to be both an employer and an employee, they have to pay the full 12.4% Social Security tax. The Social Security tax is applied to all net earnings up to the wage limit. The self-employment tax is made up of the Social Security tax and Medicare tax. As of 2021, the self-employment tax is 15.3% (12.4% Social Security tax + 2.9% Medicare Tax). The self-employment tax is only applied to 92.35% of net business earnings.

Here's an example: Ike, who runs a human resources consulting business, calculates his total net income for the year to be $200,000 after business expenses have been deducted. His self-employment tax rate will be assessed on 92.35% x $200,000 = $184,700. Since this amount is above the capped limit, his tax bill will be 15.3% x $137,700 (limit) = $21,068.01. Ike can claim an above-the-line deduction for half of his self-employment tax, or $21,068.01 ÷ 2 = $10,534.05. In effect, he gets a refund on the employer portion (6.2% Social Security + 1.45% Medicare = 7.65%) of his self-employment tax.


Not every taxpayer has to pay Social Security tax. Exemptions are available to specific groups of individuals, including:

  • Members of a religious group who are opposed to receiving Social Security benefits during retirement, if disabled, or after death
  • Nonresident aliens—that is, individuals who are neither citizens nor legal residents of the United States, who are in the country temporarily as students
  • Nonresident aliens working in the U.S. for a foreign government
  • Students who are employed at the same school where they are enrolled, and where employment is contingent upon continued enrollment

Example of Social Security Taxes

The Social Security tax is a regressive tax, meaning that a larger portion of lower-income earners' total income is withheld, compared with that of higher-income earners. Consider two employees, Izzy and Jacob. Izzy earns $85,000 for the tax year 2020 and has a 6.2% Social Security tax withheld from his pay. The federal government, in effect, collects 6.2% x $85,000 = $5,270 from Izzy to help pay for retirement and disability benefits.

Jacob, on the other hand, earns $175,000 for the tax year 2020. The Social Security tax rate will only be applied up to the limit of $137,700 (The Social Security tax limit for 2020 is $137,700; the limit jumps to $142,800 in 2021). Therefore, Jacob will pay 6.2% x $137,700 = $8,537.40 as his contribution to the country’s Social Security account for older people and people with disabilities, but his effective Social Security tax rate is $8,537.40 ÷ $175,000 = 4.87%. Izzy, with a lower income per annum, is effectively taxed at 6.2% (i.e., $5,270 ÷ $85,000).

Even households that earn a level of income to which little to no federal income tax will be applied may still have Social Security tax taken from their pay. A single taxpayer who earns $10,000 gross income in a given year, for example, will have zero income tax liability, but 6.2% may still be taken for Social Security.

Article Sources
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  1. Social Security Administration. "What Are FICA and SECA Taxes?" Accessed Oct. 23, 2021.

  2. Social Security Administration. "Social Security (Old-Age, Survivors, and Disability Insurance) Program Description and Legislative History." Accessed Oct. 23, 2021.

  3. Social Security Administration. "2021 Social Security Changes." Accessed Oct. 23, 2021.

  4. Social Security. "Fact Sheet: 2022 Social Security Changes." Accessed Oct. 23, 2021

  5. Internal Revenue Service. "Self-Employment Tax (Social Security and Medicare Taxes)." Accessed Oct. 23, 2021.

  6. Internal Revenue Service. "Topic No. 554 Self-Employment Tax." Accessed Oct. 23, 2021.

  7. Internal Revenue Service. "Publication 517: Social Security and Other Information for Members of the Clergy and Religious Workers," Pages 2–6. Accessed Oct. 23, 2021.

  8. Congressional Research Service. "Social Security: Raising or Eliminating the Taxable Earnings Base," Page 20. Accessed Oct. 23, 2021.

  9. Social Security Administration. "Contribution and Benefit Base." Accessed Oct. 23, 2021.

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