How Bonus Tax Works: Why Your Bonus Is Taxed So High

You worked hard all year and earned a $5,000 bonus — then watched nearly half of it disappear before it hit your bank account. Welcome to supplemental wage withholding, the reason bonuses feel so heavily taxed. Here’s exactly what’s happening, why, and how the math actually works out.

Why Bonuses Seem So Heavily Taxed

The short answer: bonuses are withheld at a higher rate than regular paychecks, but withholding is not the same as your actual tax bill. The IRS requires employers to withhold taxes from bonuses using a specific method that front-loads the tax hit. You reconcile everything when you file your return.

The Two Federal Withholding Methods

1. The Flat Rate Method (Percentage Method)

For bonuses under $1 million, employers may withhold at a flat 22% federal rate — regardless of your tax bracket. This is the most common approach.

On a $5,000 bonus:

• Federal withholding: $5,000 × 22% = $1,100
• FICA (7.65%): $382.50
• State tax (varies): roughly $150–$500 depending on state
• Take-home: approximately $3,200–$3,400

For bonuses above $1 million, the excess is withheld at 37%.

2. The Aggregate Method

Some employers add your bonus to your most recent regular paycheck and withhold taxes as if the combined amount is your normal pay. This can result in higher withholding if the combined amount pushes into a higher bracket.

Example: You earn $5,000/month, placing you in the 22% bracket. Your employer adds a $10,000 bonus to your next paycheck for a combined $15,000. Withholding is calculated as if you normally earn $15,000/month — temporarily treating you as being in the 32% bracket. More gets withheld upfront, but you get it back when you file.

What Your Effective Rate Actually Is

Here’s what matters: the IRS doesn’t care how your bonus was withheld. At tax time, your bonus is just ordinary income added to your other wages. It gets taxed at your marginal rate like every other dollar in that bracket.

Example with flat-rate method:

• Annual salary: $65,000
• Bonus: $10,000
• Total income: $75,000
• Marginal bracket (single, 2026): 22%
• Federal withholding on bonus: 22% = $2,200
• Actual federal tax owed on bonus: ~22% = $2,200

In this case, withholding matches reality almost exactly and you’ll neither owe nor get back much.

Where over-withholding happens: If your marginal rate is below 22% — say you’re in the 12% bracket ($47,150–$100,525 for single filers) — then the 22% flat withholding is too high and you’ll get a refund.

Where under-withholding happens: If your total income pushes into the 24% bracket, you’ll owe a bit more at filing.

FICA on Bonuses

Bonuses are subject to the same FICA taxes as regular wages:

• Social Security: 6.2% (up to the $176,100 wage base)
• Medicare: 1.45% (no cap)

If you’ve already hit the Social Security wage base through regular wages, bonuses paid after that point are only subject to the 1.45% Medicare tax — a small silver lining for higher earners.

State Tax on Bonuses

States handle bonus withholding differently:

• States with flat rates (Illinois, Massachusetts, etc.): Bonus is withheld at the same flat rate as regular wages. No surprise.
• States with progressive rates (California, New York, New Jersey): May use their own version of the aggregate method or a supplemental rate. California, for example, uses a flat 6.6% supplemental withholding rate for bonuses.
• No-income-tax states (Texas, Florida, Nevada, etc.): No state withholding on bonuses at all.

Use the paycheck calculator for your specific state to see the full after-tax picture.

Strategies to Manage Bonus Taxes

1. Contribute More to Your 401(k)

If your bonus arrives near year-end and you haven’t maxed your 401(k), ask HR to direct a portion of your bonus to your retirement account. 401(k) contributions reduce your federal and state taxable income — though not FICA.

2026 limits: $23,500 (under 50) or $31,000 (50+).

2. Max Your HSA

Health Savings Account contributions reduce taxable income. 2026 limits: $4,300 (individual) or $8,550 (family). Bonus income is a good opportunity to fund this.

3. Bunch Charitable Deductions

If you donate regularly, consider a Donor-Advised Fund (DAF) in a bonus year. You get the full deduction immediately, then distribute grants over multiple years.

4. Timing

If you have control over when a bonus is paid (e.g., you’re a business owner or it can be deferred), consider whether receiving it in a lower-income year reduces your effective rate. Note: constructive receipt rules limit this flexibility for employees.

The “Bracket Creep” Fear Is Usually Overblown

Many people worry that a large bonus will push all their income into a higher bracket. Remember: tax brackets are marginal. Only the dollars inside the higher bracket are taxed at the higher rate. A $10,000 bonus that crosses a bracket boundary results in only the dollars above the threshold being taxed at the higher rate.

Example: You earn $99,000 as a single filer. The 22% bracket ends at $100,525. A $5,000 bonus means:

• $1,525 taxed at 22% (filling the 22% bracket)
• $3,475 taxed at 24%
• The difference from “staying in 22%”: only $69.50 more in federal tax

Key Takeaways

• Bonuses are withheld at 22% federal (under $1M), but your actual tax is based on your marginal rate
• If you’re in the 12% bracket, you’ll likely get a refund — if you’re in 24%+, you may owe slightly more
• FICA (7.65%) applies to bonuses just like regular wages
• State tax treatment varies — no-income-tax states have no state withholding
• 401(k) and HSA contributions made from bonus income reduce your federal and state income tax (not FICA)
• The best tool is a paycheck calculator that models your full year income to show your effective rate