IOWA BONUS TAX · TAX YEAR 2026
Iowa bonus tax calculator
Iowa's bonus tax rate is 3.8%, its flat income tax rate, when federal tax on the bonus is withheld at the flat supplemental rate. On a $10,000 bonus with $75,000 of wages, a single filer has $380 of Iowa tax withheld, plus $2,200 of federal income tax and $765 of Social Security and Medicare, and takes home $6,655. The bonus adds $380 to the year's Iowa tax, so withholding matches the tax.
Your bonus after tax
- Take-home bonus
- $6,655.00
- Federal income tax
- $2,200.00
- Social Security and Medicare
- $765.00
- Iowa tax
- $380.00
Iowa tax for the year
- Withheld from the bonus
- $380.00
- Added by the bonus
- $380.00
- Difference
- $0.00
Iowa withholding by bonus size
What a single filer with $75,000 of other wages has withheld from bonuses of different sizes, and takes home.
| Bonus | Federal | Social Security and Medicare | State | Take-home |
|---|---|---|---|---|
| $1,000 | $220 | $77 | $38 | $666 |
| $5,000 | $1,100 | $383 | $190 | $3,328 |
| $10,000 | $2,200 | $765 | $380 | $6,655 |
| $25,000 | $5,500 | $1,913 | $950 | $16,638 |
| $50,000 | $11,000 | $3,825 | $1,900 | $33,275 |
Iowa tax withheld vs. owed
The Iowa tax withheld from a $10,000 bonus against the tax the bonus adds to a single filer's year. Over-withholding comes back in your refund; under-withholding is due when you file.
| Annual wages | Withheld | Tax added | Difference |
|---|---|---|---|
| $40,000 | $380 | $380 | $0 |
| $75,000 | $380 | $380 | $0 |
| $150,000 | $380 | $380 | $0 |
| $300,000 | $380 | $380 | $0 |
Iowa bonus tax questions
What is the Iowa bonus tax rate for 2026?
Iowa's bonus tax rate is 3.8%, its flat income tax rate, when federal tax on the bonus is withheld at the flat supplemental rate. On a $10,000 bonus that is $380 of Iowa tax.
Is a bonus taxed more than regular pay in Iowa?
No. When you file, a bonus is taxed at the same Iowa rates as the rest of your wages; only the withholding differs. For a single filer with $75,000 of wages, a $10,000 bonus adds $380 to the year's Iowa tax and has $380 withheld, so withholding matches the tax.
Why is Iowa's bonus rate 3.8%?
It is the highest Iowa rate that applies to individuals, which is also the state's flat income tax rate for 2026. Iowa uses it when the federal bonus withholding is figured at the flat supplemental rate; a bonus paid with regular wages is withheld through the tables on the combined pay.
What the calculator leaves out
- 3.8% applies when federal tax on the bonus is withheld at the flat rate; a bonus paid with regular wages is withheld on the total.
Federal income tax is withheld at the 22% supplemental rate, 37% on supplemental pay above $1,000,000 in a year. Social Security and Medicare treat the bonus as the year's last pay, so wages above $184,500 owe no more Social Security. Filing status changes only the annual comparison.