Bonus Tax in Missouri (2026)
A bonus is supplemental pay, and it is usually withheld at a flat federal rate rather than your normal bracket. Employers apply 22% to supplemental wages up to a yearly threshold, and a higher rate on the part above it. FICA comes out on top, and then the Missouri state layer applies.
If you live or work in Kansas City or St. Louis, the local earnings tax applies to a bonus too.
Worked example: a $5,000 bonus in Missouri
| Federal withholding (22%) | $1,100 |
| FICA (Social Security + Medicare) | $383 |
| Missouri withholding | $235 |
| Total withheld | $1,718 |
| You keep about | $3,282 |
Assumes year-to-date wages under the $184,500 Social Security wage base. Withholding, not final tax — it reconciles on your return.
Bonus tax calculator (2026)
| Federal withholding (flat 22%) | $1,100 |
| FICA (Social Security + Medicare) | $383 |
| Missouri withholding (4.7%) | $235 |
| You keep about | $3,282 |
Assumes your year-to-date wages are under the $184,500 Social Security wage base. Withholding, not your final tax — it reconciles on your return.
See what your regular paycheck keeps in Missouri: Missouri paycheck calculator.
Frequently asked questions
Why is my bonus taxed so high?
What you see is withholding, not your final tax. Federal rules withhold supplemental pay like a bonus at a flat 22%, which is often more than your normal rate, so the bonus looks heavily taxed. It squares up when you file, where your real rate is applied to your total income.
Does Missouri have a flat bonus withholding rate?
It depends on the state. The breakdown above shows Missouri's supplemental rate if it has one, or notes when the aggregate method applies instead.
Federal: IRS 2026 brackets (Rev. Proc. 2025-32) · FICA: IRS Topic 751 · Wage base: SSA · Missouri: Missouri Department of Revenue. Rates current as of July 16, 2026. Annual-liability estimates, not payroll withholding — see methodology.