Bonus Tax in Kansas (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 Kansas state layer applies.

Kansas withholds supplemental wages (bonuses, commissions) at 5% on top of the federal 22% and FICA. Kansas flat supplemental/bonus withholding rate is 5% when the flat method is used (KW-100).

Worked example: a $5,000 bonus in Kansas

Federal withholding (22%)$1,100
FICA (Social Security + Medicare)$383
Kansas withholding$250
Total withheld$1,733
You keep about$3,267

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
Kansas withholding (5%)$250
You keep about$3,267

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 Kansas: Kansas 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 Kansas have a flat bonus withholding rate?

It depends on the state. The breakdown above shows Kansas'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 · Kansas: Kansas Department of Revenue. Rates current as of July 16, 2026. Annual-liability estimates, not payroll withholding — see methodology.