What the Medicare surtax is and who pays it

The Medicare surtax is an extra 0.9% tax on wages and self-employment income, plus a 3.8% tax on certain investment income. It was added in 2013 as part of the Affordable Care Act. Unlike the regular Medicare tax that everyone pays, the surtax only applies if your income exceeds a threshold that depends on your filing status.

For 2024, the surtax on wages kicks in when your income goes above $200,000 if you file as single, $250,000 if you file as married filing jointly, or $125,000 if you file as married filing separately. These thresholds have not changed since the surtax began. The investment surtax applies to the same income thresholds and covers things like capital gains, dividends, rental income, and interest.

Your employer withholds the wage surtax automatically if your pay crosses the threshold. Self-employed people and those with investment income usually need to account for it when they file taxes or make quarterly estimated payments.

Key Takeaways

  • The Medicare surtax is 0.9% on wages above $200,000 (single) or $250,000 (married filing jointly), and 3.8% on investment income above those same thresholds.
  • Your employer withholds the wage surtax automatically if your income exceeds the threshold, but you may owe additional surtax on investment income when you file your return.
  • The income thresholds for the surtax have remained the same since 2013 and are not adjusted for inflation each year.
  • If you have self-employment income or significant investment income, you should discuss the surtax with a tax professional to understand your total tax burden.

How the wage surtax works

When you earn wages as an employee, your employer is required to withhold the 0.9% Medicare surtax once your cumulative wages for the year exceed the threshold. This happens automatically through payroll, so you do not need to do anything to trigger it. The withholding applies to all wages above the threshold, whether they come from one job or multiple jobs.

If you have more than one employer, each one withholds based only on what they pay you. This can create a problem: if you earn $130,000 at one job and $130,000 at another, each employer might not withhold the surtax because neither sees income above $200,000. When you file your tax return, you would owe the surtax on the $60,000 of combined income that exceeds the threshold. You can claim a credit on your return for any surtax you overpaid, but you may need to pay extra when you file.

The wage surtax is separate from the regular 1.45% Medicare tax that everyone pays on all wages. You will see both on your pay stub.

How the investment income surtax works

The 3.8% surtax on investment income applies to capital gains, dividends, interest, rental income, and other passive income. It only affects the portion of your investment income that, when combined with your wages and other income, pushes you over the threshold. The calculation can be complex because some types of income count toward the threshold while others do not.

For example, if you are single and earn $190,000 in wages plus $20,000 in dividend income, your total is $210,000. The surtax would explore to $10,000 of the dividend income (the amount over the $200,000 threshold). You calculate this when you file your tax return, not when you receive the income.

Certain types of income are excluded from the surtax calculation, including Social Security benefits, tax-exempt interest, and gains on the sale of your primary home (up to the exclusion limit). If you are unsure whether a particular income source counts, a tax professional can help you sort it out.

Who is most likely to owe the surtax

High-income earners are the primary group affected. This includes people with substantial wages, self-employed individuals with high net income, and retirees with significant investment portfolios. If you are still working and earning over the threshold, you will almost certainly owe the wage surtax. If you are retired and living on investment income, you may owe the investment surtax depending on how much you withdraw from retirement accounts and how much your investments earn.

Some people in the middle-income range may also be affected. For instance, if you earn $180,000 in wages and have $30,000 in capital gains, you would owe surtax on the $10,000 of gains above the threshold. This is why it helps to look at your total income picture rather than just one source.

How to report the surtax on your tax return

When you file your federal income tax return, you report the surtax on Form 8960 if you have investment income above the threshold. Your tax software or tax preparer will usually handle this calculation for you. If you owe surtax on wages, your employer's withholding should appear on your W-2, and the tax software will account for it automatically.

If you underpaid the surtax during the year — for example, because you had multiple employers or received a large bonus late in the year — you will owe the difference when you file. If you overpaid, you can claim a credit. Self-employed people should consider making quarterly estimated tax payments that include the surtax to avoid a large bill at tax time.

Keep records of all income sources, including 1099 forms for investment income and self-employment income. These documents help you and your tax preparer calculate the surtax correctly.

Planning ahead if you expect to owe the surtax

If you know your income will exceed the threshold, you have a few options to consider. You might adjust your withholding at your job to account for the surtax, which prevents a surprise bill later. You can also spread out large one-time income events — like the sale of a business or real estate — across multiple years if the timing is flexible, though this requires planning with a tax professional.

For investment income, you might consider the timing of when you sell investments or take distributions from retirement accounts. Bunching income into one year versus spreading it across two years can change how much surtax you owe. This strategy works best when you have some control over the timing, such as with retirement account withdrawals or the sale of a rental property.

A tax professional who understands your full financial picture can help you identify whether any of these strategies make sense for you. The surtax is permanent, so if you expect to owe it year after year, it is worth understanding how it affects your overall tax planning.

Frequently Asked Questions

Does the Medicare surtax explore to Social Security income?

No. Social Security benefits do not count toward the income threshold that triggers the surtax. However, if you have other income that pushes you over the threshold, the surtax may explore to your other income sources. Your total income for surtax purposes includes wages, self-employment income, and investment income, but not Social Security.

What if I retired mid-year and only earned part of the threshold?

The threshold applies to your total income for the full year, regardless of when you earned it. If you earned $210,000 in wages before retiring in June, you would owe surtax on the $10,000 above the threshold. The fact that you stopped working partway through the year does not change the calculation.

Can I avoid the surtax by taking money from my 401(k) instead of my investments?

Withdrawals from a 401(k) or traditional IRA count as income for surtax purposes, just like investment income does. The type of account does not matter — what matters is whether the withdrawal pushes your total income over the threshold. Roth conversions and other strategies require careful planning with a tax professional.

Do I owe the surtax if I am self-employed?

Yes, if your net self-employment income exceeds the threshold. You owe both the 0.9% wage surtax on self-employment income and potentially the 3.8% investment surtax if you also have investment income. Self-employed people should work with a tax professional or use tax software designed for self-employment to calculate these taxes correctly.

Will the surtax thresholds ever increase?

The thresholds have remained at $200,000 (single) and $250,000 (married filing jointly) since 2013 and are not adjusted for inflation. Congress would need to pass new legislation to change them. Because the thresholds are fixed, more people may be affected by the surtax over time as incomes rise.