What 22% does and does not mean
IRS Publication 15 permits an optional flat supplemental method when its conditions apply. If regular-wage income tax was not withheld by the employer in the current or preceding calendar year, the required aggregate method can produce a different amount. This tool rejects unsupported optional-flat scenarios rather than applying 22% automatically.
The $1 million boundary applies to supplemental wages
Regular wages do not themselves fill this threshold. For a payment crossing the boundary, the eligible portion below it uses the selected supported method and the portion above it uses the mandatory 37% rate. For example, $200,000 of current supplemental pay after $900,000 of earlier supplemental wages gives $59,000 income-tax withholding under the supported 22%/37% split. This is formula arithmetic, not an earnings claim or a full tax-return example.
Federal payroll taxes remain
For the ordinary FICA-covered cash bonus modeled here, Social Security is 6.2% up to the employer’s remaining 2026 $184,500 wage base. Medicare is 1.45% without that cap. Employer Additional Medicare withholding is 0.9% on wages above $200,000, regardless of filing status; the annual-return threshold may differ. Separate year-to-date bases avoid assuming that every payroll base equals gross annual salary.
Official example and method distinction
Publication 15, section 7, example 3 shows $220 federal income-tax withholding on Sharon’s $1,000 bonus under the flat method. Its aggregate wage-bracket example 2 instead gives $114. This tool implements the flat method only and does not pretend that a percentage-method annualization reproduces the wage-bracket example.
Scope and exclusions
Ordinary FICA-covered cash bonuses only, for 2026. State/local tax, benefit deductions, retirement contributions from the bonus, exempt employment, noncash awards, gross-ups, employer tax costs and the aggregate withholding method are not modeled. Employer payroll records determine actual prior wages and eligibility. Bonus compensation is included with other income when determining annual liability; the withheld amount does not promise a refund.
Sources and review
Reviewed October 21, 2026 by Numbriv editorial team. IRS Publication 15, section 7; SSA contribution and benefit base; IRS Additional Medicare withholding questions. Methodology · Review log.
Bonus questions
Does my filing status change the flat 22% rate?
Not under this optional method. Filing status can affect annual liability and an aggregate-method calculation, which are different questions.
Can my employer choose the aggregate method instead?
The IRS provides more than one permitted method when the relevant conditions apply. This tool calculates only the stated flat method and does not promise the employer selected it.
Does the $1 million threshold refer to all salary?
No. It concerns calendar-year supplemental wages under the applicable employer-aggregation rules, not all ordinary salary.
Why can Social Security withholding on a bonus be smaller late in the year?
Earlier covered wages may already have used part or all of that employer’s annual Social Security wage base. Medicare follows a different base and threshold.
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