A $5,000 bonus shows up in your account as $3,400 and change, and the first reaction is almost always the same: someone taxed my bonus at a punishment rate. That is not what happened. Bonuses are not a separate tax category and there is no penalty bracket for them. What changed was the withholding method your payroll department used, and withholding is a deposit, not a bill.
Understanding the difference is worth real money, because the fix runs in both directions. Some people are handing the government an interest-free loan every December. Others are quietly building a balance due they will discover in April.
What counts as a supplemental wage
The IRS splits your pay into two buckets. Regular wages are the predictable amount tied to your normal pay period. Everything else is a supplemental wage, and IRS Publication 15 puts a long list in that second bucket: bonuses, commissions, overtime pay, severance, back pay, retroactive raises, accumulated sick leave payouts, awards and prizes, and taxable fringe benefits.
That list surprises people. Overtime in particular. If you work a lot of extra hours, a meaningful slice of your annual income may be running through supplemental withholding rules without you ever having noticed.
The two methods your employer can choose
Once a payment lands in the supplemental bucket, payroll picks one of two approaches, and you rarely get a vote.
The flat percentage method is the one that produces the famous number. If your employer identifies the bonus separately from your regular wages, it can withhold federal income tax at a flat 22% on supplemental wages up to $1 million for the year. Above $1 million, withholding on the excess jumps to a mandatory 37%. That 22% is not an estimate of your tax rate. It is a default the IRS set, and it is applied identically to a warehouse worker earning $38,000 and a director earning $210,000.
The aggregate method is the other option. Payroll lumps the bonus in with your regular paycheck for that period, calculates withholding on the combined amount as though that were your normal earnings, subtracts what it already withheld on the regular portion, and treats the remainder as withholding on the bonus. Because payroll systems annualize, a single large check can look like an enormous salary for one pay period, which is why the aggregate method sometimes withholds far more than 22%. It usually corrects itself on the return.
Neither method knows anything about your spouse’s income, your mortgage interest, your student loan interest, or the fact that you contributed to a traditional IRA. Withholding is a rough guess made by a payroll system with incomplete information.
Withholding is not your tax
This is the piece that resolves most of the confusion. The 22% that disappeared from your bonus is a prepayment credited against your total federal income tax for the year. When you file, the IRS adds up everything you earned, applies the actual brackets, subtracts your deductions and credits, and compares the result to what was withheld. Too much withheld means a refund. Too little means a payment.
So the practical consequence depends entirely on your marginal rate.
If your marginal rate is 12%, that flat 22% overshot by ten percentage points on every bonus dollar. You will get it back, but not until you file, and in the meantime the money sat somewhere earning you nothing. On a $5,000 bonus, that is roughly $500 parked with the Treasury for up to fifteen months.
If your marginal rate is 24%, 32%, or higher, the flat 22% undershot. Nobody is going to warn you. The shortfall surfaces as a smaller refund or a balance due, and if it is large enough it can trigger an underpayment penalty even though you did nothing wrong.
The taxes that do come out no matter what
Federal income tax withholding is only part of the deduction. Social Security tax applies at 6.2% until your year-to-date wages reach the 2026 wage base of $184,500, after which it stops for the rest of the calendar year. Medicare applies at 1.45% on every dollar with no cap, plus an additional 0.9% on wages above $200,000 for single filers and $250,000 for married couples filing jointly. State income tax withholding runs on its own rules, and several states publish their own flat supplemental rates.
Stack those together and a 22% federal flat rate becomes something closer to 30% or more on the check itself, which is why the deposit so often lands well below what people expected.
The overtime wrinkle that is new for 2026
There is a change worth knowing about if overtime is a regular part of your income. The deduction for qualified overtime compensation is in effect for 2026, worth up to $12,500 for single filers and $25,000 for joint filers, and it begins phasing out at $150,000 of income for single filers and $300,000 for joint filers.
Two details trip people up. First, only the overtime premium required under the Fair Labor Standards Act qualifies, meaning the extra half in time-and-a-half, not the whole overtime check and not a richer overtime rate your employer offers voluntarily. Second, and this is the part that matters for your paycheck, none of it changes withholding. Your employer still withholds on overtime the way it always has. The IRS updated its guidance in August 2026 and requires employers to report qualified overtime compensation separately on your W-2 in Box 12 using code TT, but the benefit itself arrives when you file, not in your weekly deposit.
If you work substantial overtime, that means your 2026 withholding is likely running ahead of your actual liability, and the correction comes as a larger refund rather than a fatter paycheck.
What you can do about any of it
The lever is Form W-4, and it is more flexible than most people realize.
If your bonuses are consistently over-withheld because your marginal rate sits below 22%, you can reduce withholding on your regular paychecks to compensate. Step 4(b) of the W-4 lets you enter expected deductions beyond the standard deduction, which lowers withholding across the year. Ask your payroll department for a new W-4 at any time. You are not limited to January.
If you are consistently under-withheld because your household income puts you in the 24% bracket or above, Step 4(c) lets you request a specific extra dollar amount withheld from each paycheck. The IRS Tax Withholding Estimator will tell you what that number should be, and it accounts for a spouse’s job and expected bonuses if you enter them.
There is a third option that works especially well with a known bonus. Many employers let you set a separate 401(k) deferral percentage for bonus payments. Diverting part of the bonus into the plan reduces the taxable amount, which reduces withholding on it, and the money ends up invested rather than sitting in a checking account waiting to be spent. Some people run the same play with an HSA if their plan allows a lump contribution.
None of this changes what you owe. It changes when you pay it and who holds the money in the meantime, and over a career of annual bonuses that timing is worth more than it sounds.
The one thing not worth doing is treating the 22% as evidence that bonuses are taxed unfairly. Look at last year’s return instead. If you got a large refund, your withholding is too high and your bonus is part of the reason. If you owed, it is too low, and the same bonus is part of that reason too.