Profit sharing is taxed the same way a bonus is. The IRS lumps both into a category called supplemental wages, which means the same federal withholding rules, the same Social Security and Medicare taxes, and the same year-end reconciliation apply whether your employer calls the check a bonus, a profit-sharing distribution, a commission, or something else. The surprise for most people isn’t the classification. It’s that the amount withheld from the check often doesn’t match what you’ll actually owe when you file.
Why the Two Payments Are Treated Identically
The IRS defines supplemental wages as any wage payment that isn’t part of your regular paycheck schedule. Bonuses, profit-sharing distributions, commissions, overtime, severance, awards, and back pay all fall inside that single bucket.1Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide Whichever label your employer uses, the payroll department runs the same calculation.
That shared classification is what drives the rest of the answer. The withholding percentage, the FICA treatment, and how the money shows up on your W-2 don’t depend on the name of the payment.
How Your Employer Withholds Federal Income Tax
Employers pick one of two methods to calculate federal income tax on supplemental wages. Which one they use can noticeably change your take-home amount, even though your actual tax liability at year-end stays the same either way.
Flat 22% Method
Most employers use the simpler option: withhold a flat 22% of the payment for federal income tax. This rate is set by law, not chosen by your employer.1Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide They can’t decide to use 15% or 25% instead.
One threshold matters at the top: if your total supplemental wages from a single employer exceed $1 million in a calendar year, every dollar above that mark is withheld at a mandatory 37%, regardless of what your W-4 says.1Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide
Aggregate Method
Some employers combine the supplemental payment with your most recent regular paycheck and calculate withholding on the combined total as if it were a single pay period. This pulls a higher percentage from the check, because the temporary spike in that pay period annualizes into a much larger apparent salary. If your normal biweekly pay is $3,000 and a $10,000 profit-sharing payment lands in the same check, the system withholds as if you earn $13,000 every two weeks.
Workers who get hit with aggregate-method withholding tend to see a bigger refund at tax time, since the withholding overshoots their real annual bracket. It feels worse in the moment and usually evens out when you file.
Withholding Is Not Your Tax Rate
This is where people get tripped up. The 22% flat rate is a collection mechanism, not what you actually owe. Your real federal income tax on the money depends on your total taxable income for the year and which bracket the dollars fall into. For 2026, single-filer brackets start at 10% on income up to $12,400 and top out at 37% on income above $640,600.2Internal Revenue Service. Tax Inflation Adjustments for Tax Year 2026
If you sit in the 24% bracket (single filers with income over $105,700), the 22% withheld from your bonus or profit-sharing check underpays by two percentage points on every dollar. On a $15,000 payout, that’s roughly $300 you’ll owe at filing. If you’re in the 12% bracket, the flat rate overshoots and you get some of it back as a refund. Neither situation changes your total tax bill. Only whether you settle up or get money back in April.
You can adjust for this. Form W-4 has a line in Step 4(c) for additional withholding, and if you know a large payout is coming late in the year, raising your withholding on your remaining regular paychecks can close the gap before it becomes an underpayment.3Internal Revenue Service. Form W-4 – Employee’s Withholding Certificate (2026)
Social Security and Medicare Also Apply
On top of federal income tax, both payment types are subject to FICA. Your employer withholds 6.2% for Social Security and 1.45% for Medicare, and matches those amounts with its own contribution.4Internal Revenue Service. Publication 15-A (2026), Employer’s Supplemental Tax Guide These are the same rates that come out of your regular paycheck.
Social Security has a ceiling. In 2026, only the first $184,500 of combined wages is subject to the 6.2% tax.5Social Security Administration. Contribution and Benefit Base If your regular salary has already pushed you past that limit by the time the payout arrives, no Social Security tax comes out of it. If you’re partway to the cap, only the portion that brings you up to $184,500 is taxed. Medicare has no wage ceiling; the 1.45% applies to every dollar.
Higher earners face an additional 0.9% Medicare surtax on wages over $200,000 for single filers or $250,000 for married couples filing jointly.6Internal Revenue Service. Topic No. 560, Additional Medicare Tax Your employer starts withholding the extra 0.9% once your wages from that job cross $200,000 in the calendar year, regardless of your filing status. If you’re married and the actual threshold is $250,000, you reconcile the difference on your return.
State Withholding Varies
Most states with an income tax follow the federal treatment and classify profit sharing and bonuses as supplemental wages, often applying a flat state withholding rate. The percentage varies widely by state. States without an income tax take nothing. Check your state’s revenue department for the rate that applies to your payment.
One Big Exception: Profit Sharing Paid Into a Retirement Plan
Everything above assumes cash lands in your bank account. If your employer instead routes profit-sharing contributions into a qualified retirement plan such as a 401(k), the tax picture is completely different. Those contributions aren’t included in your taxable income for the year they’re made, and no federal or state income tax comes out at the time of the contribution.7Office of the Law Revision Counsel. 26 USC 401 – Qualified Pension, Profit-Sharing, and Stock Bonus Plans The money grows tax-deferred, and you pay ordinary income tax on it when you take distributions in retirement.
Pull the money out before age 59½ and you’ll generally owe a 10% additional tax on top of the regular income tax.8Office of the Law Revision Counsel. 26 USC 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts Exceptions cover disability, separation from service after age 55, and substantially equal periodic payments, but the default makes early access expensive.
Employer profit-sharing deposits also don’t eat into your own 401(k) contribution room. Your salary deferrals and your employer’s contributions fill separate buckets within the same overall defined-contribution ceiling of $72,000 for 2026, with an employee deferral limit of $24,500.9Internal Revenue Service. 2026 Amounts Relating to Retirement Plans and IRAs One thing to check before counting a plan balance as yours: vesting schedules can delay ownership of employer contributions for up to three or six years depending on the structure your plan uses.10Office of the Law Revision Counsel. 26 USC 411 – Minimum Vesting Standards
Avoiding an Underpayment Penalty
A large payout combined with flat 22% withholding can leave a real gap if you’re in a higher bracket, and if the gap is big enough the IRS charges an underpayment penalty. You’re generally safe from the penalty if you owe less than $1,000 at filing, or if your total withholding and estimated payments covered at least 90% of your current-year tax or 100% of your prior-year tax (110% if your adjusted gross income was over $150,000).11Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
If a mid-year payout looks like it will leave you short, you have two practical options. Submit an updated W-4 to raise withholding from your remaining regular paychecks, or send a quarterly estimated payment directly to the IRS. The penalty accrues from the date the underpayment began, not from April 15, so waiting until you file only makes it bigger.