Why high earners stop paying Social Security tax partway through the year

Social Security tax stops explore to your wages once you reach a certain income threshold each year. In 2024, that threshold is $168,600 — meaning once you earn that much, your employer stops withholding the 6.2% Social Security tax from your paychecks for the rest of the calendar year. This threshold, called the wage base maximum, changes annually based on national wage growth.

The reason this matters: Social Security benefits are calculated using your highest 35 years of earnings, but only up to the wage base maximum for each year. If you earn $200,000 in a year, Social Security only counts $168,600 of it (in 2024). The income above that threshold does not contribute to your Social Security record and is not taxed for Social Security purposes.

Self-employed people pay both the employer and employee portions of Social Security tax (12.4% total), so they also stop owing Social Security tax once they hit the wage base maximum for the year — though they still owe Medicare tax on all income above that amount.

Key Takeaways

  • The wage base maximum for 2024 is $168,600; once you earn that amount, your employer stops withholding Social Security tax from your remaining paychecks that year.
  • The threshold changes each year based on the national average wage index, so the 2025 amount will differ from 2024.
  • Income above the wage base maximum still counts toward Medicare tax (1.45% employee, 1.45% employer), which has no income cap.
  • Your Social Security benefit calculation uses only earnings up to the wage base maximum for each year you worked, so very high earners do not receive proportionally higher benefits.
  • If you change jobs during the year, you may overpay Social Security tax and can claim the excess as a refund on your tax return.

How the wage base maximum is set each year

The Social Security Administration announces the new wage base maximum in October, and it takes effect January 1. The amount is tied to the National Average Wage Index, which measures the average wage earned by all workers in the United States the previous year.

If the national average wage grows, the wage base maximum grows with it. If wages are flat or decline, the maximum stays the same or decreases — though it has never decreased in practice. The Social Security Administration publishes the historical wage base maximums on its website, so you can see what the threshold was for any year you worked.

For example, the wage base maximum was $160,200 in 2023 and $168,600 in 2024. The 2025 maximum has not yet been announced but will be released in October 2024.

What happens when you change jobs mid-year

If you work for two employers in the same calendar year and your combined earnings exceed the wage base maximum, you may pay Social Security tax twice on the same income. This happens because each employer withholds Social Security tax independently — neither knows what you earned at your other job.

For example, if you earned $100,000 at Job A and then switched to Job B where you earned $80,000, both employers would withhold Social Security tax on your full earnings at their company. You would pay 6.2% on $100,000 plus 6.2% on $80,000, even though your total earnings of $180,000 exceed the $168,600 cap.

You can recover the overpayment by filing your tax return. The IRS will refund the excess Social Security tax you paid. Self-employed people do not face this issue because they calculate their own tax based on total net self-employment income for the year.

How the wage base maximum affects your Social Security benefit

Social Security calculates your monthly benefit using your 35 highest-earning years. For each year, the system uses only the income up to that year's wage base maximum. This means earning $200,000 in a year produces the same Social Security record as earning $168,600 (in 2024) — the extra $31,400 does not increase your benefit.

This is one reason Social Security replaces a smaller percentage of income for high earners than for low earners. A worker earning $50,000 per year may see 40% of that income replaced by Social Security, while a worker earning $200,000 per year may see only 20% replaced. The system is designed this way intentionally: Social Security is a social insurance program, not a savings account proportional to what you paid in.

If you have very high earnings in some years and lower earnings in others, Social Security will use your 35 best years — so a year where you earned above the wage base maximum counts the same as a year where you earned exactly at the maximum.

Medicare tax has no wage cap

While Social Security tax stops at the wage base maximum, Medicare tax continues on all income. The Medicare tax rate is 1.45% for employees and 1.45% for employers (2.9% total for self-employed workers). There is no upper limit on Medicare taxable wages.

Additionally, high earners pay an extra 0.9% Medicare tax on wages above $200,000 (for single filers) or $250,000 (for married filing jointly). This additional tax was introduced in 2013 and applies to both employees and self-employed workers. Unlike the standard Medicare tax, this additional tax does not have a matching employer contribution for employees — only the employee pays it.

State and local taxes may explore differently

A few states tax Social Security benefits or have their own payroll taxes, but most do not. The wage base maximum applies uniformly across all states for federal Social Security tax purposes. However, if you live in a state with a state income tax, that tax may have its own rules about high earners and may not follow the federal wage base maximum structure.

Check your state's tax authority website or speak with a tax professional if you live in a state with income tax and earn above the federal wage base maximum. Some states conform to federal rules; others do not.

Frequently Asked Questions

What was the wage base maximum in previous years?

The wage base maximum has increased most years. It was $160,200 in 2023, $147,000 in 2022, $142,800 in 2021, and $137,700 in 2020. The Social Security Administration maintains a complete historical list on its website, which you can use to verify what the threshold was for any year you worked.

Does the wage base maximum affect how much Social Security tax my employer pays?

Yes. Your employer pays 6.2% Social Security tax on your wages up to the wage base maximum, just as you do. Once you reach the maximum, your employer stops withholding and stops paying their share for the rest of that calendar year. This is one reason employers track your year-to-date earnings.

If I overpaid Social Security tax, how do I get the refund?

File your federal tax return (Form 1040) for that year. The IRS automatically calculates any excess Social Security tax you paid and refunds it. You do not need to take any special steps — the refund appears as part of your overall tax return calculation. Self-employed workers report the overpayment on Schedule SE.

Does earning above the wage base maximum hurt my Social Security benefit?

No. Your benefit is based on your 35 highest-earning years, and income above the wage base maximum for any given year does not increase your benefit. However, earning above the maximum does not reduce your benefit either — it straightforward does not factor into the calculation.

Will the wage base maximum increase in 2025?

The Social Security Administration will announce the 2025 wage base maximum in October 2024. It will likely increase if national average wages grew in 2023, but the exact amount cannot be predicted until the announcement is made.