Iowa State Income Tax Withholding
Last Updated: January 2026
Overview
Iowa uses a flat income tax rate, having transitioned from a progressive system. The simplified structure makes withholding calculations straightforward for employers.
2026 Tax Rates
| Tax Type | Rate |
|---|---|
| Flat Tax Rate | 3.80% |
Note: Iowa converted to a flat tax system as part of tax reform. The flat rate applies to all taxable income.
Deductions and Exemptions
Iowa uses federal taxable income as the starting point, then applies Iowa-specific adjustments.
Standard Deduction
Iowa does not have a separate standard deduction. The calculation begins with federal adjusted gross income (AGI) and applies Iowa modifications.
Personal Exemption Credit
| Credit Type | Amount |
|---|---|
| Personal Exemption Credit | $40 per exemption |
Special Considerations
State W-4 Form
Iowa requires Form IA W-4 (Employee Withholding Allowance Certificate). Employees must complete this form in addition to the federal W-4.
Iowa-Specific Adjustments
Iowa taxable income differs from federal due to various additions and subtractions. Common adjustments include:
- Certain federal deductions not allowed in Iowa
- Iowa-specific deductions and credits
No Local Income Taxes
Iowa does not have local income taxes. The state rate applies uniformly across all jurisdictions.
School District Surtax (Historical)
Iowa previously had school district surtaxes, but these have been eliminated. No local or school district withholding is required.
Reciprocal Agreement
Iowa has a reciprocal agreement with Illinois:
| Reciprocal State |
|---|
| Illinois |
Iowa residents who work in Illinois can claim exemption from Illinois withholding. Illinois residents who work in Iowa can claim exemption from Iowa withholding.
Pension/Retirement Income
Iowa provides favorable treatment for pension and retirement income. This affects annual tax returns but generally does not impact wage withholding.