Filing and paying Iowa income tax
- Return
- Form IA 1040, due April 30.
- School district
- Enter the district you lived in on December 31; it sets your surtax rate on line 19.
- Withholding
- Employers use the 2026 Iowa withholding formula with Form IA W-4, both revised for 2026 to reflect the federal changes.
To see how Iowa sits against every other state on top rate, bracket count and standard deduction, see state income tax rates for 2026 — all 51 jurisdictions in one sortable table.
How Iowa Income Tax Compares to Neighboring States
Total income tax (federal + state) on a $100,000 annual salary in 2026, single filer using the standard deduction:
| State | State Tax | Total Income Tax | vs. Iowa |
|---|---|---|---|
| Iowa (here) | $3,148 | $16,318 | — |
| Minnesota | $5,277 | $18,447 | +$2,128 |
| Wisconsin | $4,428 | $17,598 | +$1,279 |
| Illinois | $4,805 | $17,975 | +$1,657 |
| Missouri | $3,670 | $16,840 | +$522 |
| Nebraska | $3,670 | $16,840 | +$522 |
A negative "vs." figure means that state collects less total income tax than Iowa. Federal portion is identical across states; only state tax varies.
Frequently Asked Questions
What is the Iowa state income tax rate for 2026?
Iowa has a flat 3.8% state income tax rate for 2026. The rate is the same regardless of income — applied to taxable income after the standard deduction. Federal rates (10%–37%) layer on top.
How much income tax will I pay in Iowa on a $100,000 salary?
For a single filer earning $100,000 in Iowa in 2026, expect approximately $13,170 in federal income tax and $3,148 in Iowa state income tax — for a total income tax of about $16,318, an effective rate of 16.3%. This excludes FICA (Social Security and Medicare), which adds roughly 7.65% on top.
What is the Iowa income tax rate for 2026?
A flat 3.8% on all taxable income, the same as 2025.
Does Iowa have a standard deduction?
Iowa starts from federal taxable income, so the federal standard deduction ($16,100 single for 2026) is already taken out.
What is the Iowa school district surtax?
A local add-on equal to a percentage of your Iowa income tax, set by your school district of residence. For 2025 it ranges from 0% to 20%.
Does Iowa tax retirement income?
Not Social Security, and not pension or IRA income for people 55 or older, disabled, or a qualifying surviving spouse.
For the preferential federal rates on long-term gains, see the Capital Gains Tax Calculator. For the federal brackets, standard deduction, and Social Security wage base that sit underneath this state calculation, see 2026 Tax Calculators.