Roth conversion taxes in Iowa (2026)
By Mario Bailey · Published · Last reviewed
Iowa has a flat 3.8% on ordinary income, but it excludes retirement income from state tax, and IRA distributions (including Roth conversions) fall under that exclusion as this calculator models it. At age 66, the computed state tax on a $50,000 conversion is $0 at all three income levels below. Federal tax still applies in full.
Computed example: $50,000 conversion
State tax only (federal not included), age 66, standard deduction, no other state adjustments. Computed with the same functions the calculator uses.
| Filing status | Baseline income | State tax without conversion | With $50,000 conversion | Tax on the conversion | Effective rate |
|---|---|---|---|---|---|
| Single | $40,000 | $0 | $0 | $0 | 0.0% |
| Single | $80,000 | $0 | $0 | $0 | 0.0% |
| Single | $150,000 | $0 | $0 | $0 | 0.0% |
| Married filing jointly | $40,000 | $0 | $0 | $0 | 0.0% |
| Married filing jointly | $80,000 | $0 | $0 | $0 | 0.0% |
| Married filing jointly | $150,000 | $0 | $0 | $0 | 0.0% |
Social Security and retirement income
Iowa does not tax Social Security benefits. A conversion can still raise the federally taxable share of your benefits through the provisional income formula. Iowa excludes retirement income from state tax entirely (for filers age 55 and over), which covers IRA distributions including Roth conversions as this calculator models it.
FAQ
Does Iowa tax Roth conversions?
Effectively no for retirees. Iowa has an income tax, but its retirement-income exclusion covers IRA conversions as modeled here, so the computed state tax on the example conversion at age 66 is $0. Federal tax applies in full.
Does Iowa tax Social Security benefits?
No. Social Security benefits are not subject to Iowa income tax.
What is the top Iowa rate on a conversion in 2026?
The nominal top flat rate is 3.8%, though the retirement-income exclusion can reduce the effective cost to $0 for retirees.
Model your Iowa conversion in the calculator
Rate data source: https://revenue.iowa.gov/press-release/2025-10-21/idr-announces-2026-individual-income-tax-and-interest-rates (Iowa IDR: 3.8% flat rate for 2026)