Bonuses are not taxed at a higher tax rate than your regular salary, but they are frequently subject to higher initial tax withholding. Under IRS rules (Publication 15-T), bonuses and commissions are classified as “supplemental wages.” When employers issue a bonus, federal law requires a flat 22% federal supplemental withholding rate (or 37% on amounts over $1 million). When combined with mandatory FICA taxes (7.65%) and state supplemental withholding (which can exceed 10% in states like California), total upfront deductions often exceed 35% to 42% of your gross bonus. However, when you file your annual tax return, your bonus is treated simply as ordinary income, and any over-withheld funds are refunded directly to you.
Key Takeaways
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Withholding vs. Actual Tax: The IRS withholds a flat 22% federal rate on supplemental wages, but your actual liability is determined by your annual marginal tax bracket on Form 1040. -
The 40% Illusion: Federal (22%) + FICA (7.65%) + State Withholding (up to 10.23% in CA, 9.62% in NY) creates an aggregate upfront haircut of 35% to 42%. -
The Aggregate Method Shock: If your employer bundles your bonus with a regular paycheck, payroll software assumes you earn that swollen amount every cycle, spiking withholding into 32%+ brackets. -
You Never Get Taxed Twice: Bonus withholdings are credited directly against your total annual federal and state tax bill when filing your yearly return.
Supplemental Wages: Why the IRS Treats Bonuses Differently
The Internal Revenue Code categorizes all employment compensation into two distinct classes:
- Regular Wages: Base hourly pay, contractual salaries, and predetermined compensation paid at regular intervals (weekly, bi-weekly, semi-monthly). These follow standard progressive withholding tables derived from your Form W-4.
- Supplemental Wages: Compensation paid outside or in addition to regular wages. This includes discretionary bonuses, performance incentives, annual profit-sharing distributions, commissions, signing bonuses, and severance pay.
Because supplemental payments are irregular and unpredictable, the IRS does not require payroll departments to run standard progressive brackets on each bonus check. Instead, the IRS mandates specific supplemental withholding rules under IRS Publication 15-T.
The Two Methods Employers Use to Withhold Bonus Taxes
Your employer must choose between two approved IRS methodologies when processing a bonus:
1. The Percentage Method (Flat 22%)
If your bonus is paid as a separate line item or on a dedicated check, the employer applies a flat 22.00% federal withholding rate on all supplemental earnings up to $1,000,000 for the calendar year. Any supplemental wages in excess of $1,000,000 are mandatorily withheld at the highest statutory federal rate of 37.00%.
2. The Aggregate Method
If your employer combines your bonus with your normal bi-weekly or semi-monthly paycheck into a single lump-sum deposit, they may calculate withholding using the aggregate method:
- The payroll software adds your regular wages and your bonus together.
- It calculates federal income tax on the entire combined sum as if that were your standard recurring salary for every pay period throughout the entire year.
- It subtracts the tax already calculated on your regular salary.
- The remaining tax is withheld from your bonus.
Why this hurts: If you earn $3,000 bi-weekly ($78,000/year, sitting in the 12% to 22% bracket) and receive a $10,000 bonus on the same check, the aggregate system calculates withholding as if you earn $13,000 every two weeks ($338,000/year). As a result, portions of your bonus are withheld at 24%, 32%, or even 35% rates.
Full Anatomy of a $10,000 and $50,000 Bonus: Where the Money Goes
The table below breaks down the upfront tax deductions on a $10,000 bonus and a $50,000 bonus for an employee in California using the standard percentage method (assuming cumulative wages have not yet surpassed the Social Security cap):
| Withholding Component | Withholding Rate | Deduction on $10,000 Bonus | Deduction on $50,000 Bonus | Where Funds Go |
|---|---|---|---|---|
| Federal Supplemental Withholding | 22.00% Flat | $2,200.00 | $11,000.00 | IRS (Federal Treasury) |
| Social Security (OASDI) | 6.20% Flat | $620.00 | $3,100.00 | Social Security Trust Fund |
| Medicare (Hospital Insurance) | 1.45% Flat | $145.00 | $725.00 | Medicare Trust Fund |
| California State Supplemental (SIT) | 10.23% Flat | $1,023.00 | $5,115.00 | California FTB |
| California Disability (SDI) | 1.10% Flat | $110.00 | $550.00 | State Disability Insurance Fund |
| Total Upfront Deductions | 40.98% | $4,098.00 | $20,490.00 | Total Withholdings |
| Net Take-Home Bonus | 59.02% | $5,902.00 | $29,510.00 | Direct Deposit into Account |
In zero-income-tax states such as Texas, Florida, or Washington, the total withholding on the same $10,000 bonus drops from $4,098 down to $2,965 (leaving $7,035 net) because zero state income tax or disability deductions apply.
Model Your Bonus Take-Home Pay
Compare federal withholding, state rates, and FICA deductions across all 50 states with our free paycheck tax calculator.
State Supplemental Withholding Rates Compared
State taxing authorities establish their own statutory supplemental tax withholding percentages. Here is how popular states handle bonus withholdings:
| State | Supplemental Bonus Withholding Rate | Rules & Notes |
|---|---|---|
| Texas (TX) | 0.00% | No state personal income tax |
| Florida (FL) | 0.00% | No state personal income tax |
| Washington (WA) | 0.00% | No personal earned wage income tax |
| California (CA) | 10.23% | Flat statutory rate on supplemental wage bonuses |
| New York (NY) | 9.62% | Supplemental rate (plus NYC local withholding if resident) |
| Illinois (IL) | 4.95% | Standard flat personal income tax rate |
| Pennsylvania (PA) | 3.07% | Standard flat statutory tax rate |
The Social Security Wage Cap Factor
For the 2026 tax year, the Social Security (OASDI) wage base cap is set at $176,100. If your cumulative base salary and earlier compensation have already crossed $176,100 prior to receiving your bonus, your employer will not withhold the 6.2% Social Security tax from your bonus check. You will only pay the 1.45% Medicare tax, immediately boosting your net take-home pay by 6.2%.
Tax Return Reconciliation: How You Get Over-Withheld Cash Back
When you file your IRS Form 1040 the following spring, all of your earnings—base salary, hourly wages, and bonuses—are pooled into a single Adjusted Gross Income (AGI) figure. Your deductions (standard or itemized) are applied, and your true tax liability is computed using progressive marginal tax brackets:
- If your marginal bracket is 12%: The 22% federal withholding on your bonus was too high. The IRS will credit the extra 10% back to you as a federal tax refund.
- If your marginal bracket is 24% or 32%: The 22% flat withholding was lower than your true top marginal rate. You will owe the difference between the 22% withheld and your actual marginal bracket when submitting your return.
Frequently Asked Questions
Bonuses often have approximately 35% to 42% withheld upfront due to the combination of the mandatory 22% federal supplemental rate, 7.65% FICA taxes (Social Security and Medicare), and state supplemental income taxes (such as 10.23% in California or 9.62% in New York). However, this is only withholding; your actual final tax rate is determined on your annual tax return.
Only supplemental wages exceeding $1,000,000 in a single calendar year are mandatorily withheld at the top 37% federal rate. All supplemental earnings up to $1,000,000 are withheld at the standard flat 22% federal rate under IRS Publication 15-T rules.
On a $50,000 bonus using the percentage method, federal withholding is 22% ($11,000) and FICA taxes equal 7.65% ($3,825 assuming under the cap). In a state without income tax, total withholdings equal $14,825, leaving $35,175 net. In high-tax states like California, additional state withholdings of ~$5,665 reduce net take-home to approximately $29,510.
If your employer uses the aggregate method—bundling your bonus with your standard salary on a single paycheck—the payroll computer annualizes the entire amount and treats you as earning a substantially higher annual income. This artificially pushes withholding into higher brackets (such as 32% or 35%) for that specific check.
No. Bonuses are never taxed twice. The deductions taken from your bonus paycheck are simply advance tax prepayments sent to the IRS and state treasury. When you file Form 1040, all withheld dollars are credited against your true tax liability, and any excess withholding is returned to you as a refund.