Idaho Income Tax Rate History
Idaho's top marginal income tax rate fell from 6.93% in 2021 to 5.30% in 2026, a cut of 1.63%. Idaho replaced its graduated schedule with a single rate in 2023.
6 sourced years, 2 of them from Idaho's own revenue department and the rest from Tax Foundation's dated annual editions. Nothing is interpolated. How the two differ.
Idaho against the national median
One marker per sourced year. Lines join the points to show direction; no value between markers is implied.
Year by year
| Year | Top rate | Structure | Change | Basis | Source |
|---|---|---|---|---|---|
| 2021 | 6.93% | graduated | — | As of 1 January | Tax Foundationprov. |
| 2022 | 6.00% | graduated | −0.93% | As of 1 January | Tax Foundationprov. |
| 2023 | 5.80% | flat | −0.20% | As of 1 January | Tax Foundationprov. |
| 2024 | 5.80% | flat | — | As of 1 January | Tax Foundationprov. |
| 2025 | 5.30% | flat | −0.50% | Enacted for the year | Idaho State Tax Commission |
| 2026 | 5.30% | flat | — | Enacted for the year | Idaho State Tax Commission |
2025: Tax Foundation's 2025 edition shows 5.695% as of 1 January 2025. The figure published here is the rate enacted for the tax year, from the state's own source; the two differ where a rate changed after 1 January or where a scheduled cut was still contingent when that edition went to press.
Every change
- 2022: cut of 0.93% — 6.93% to 6.00%.
- 2023: cut of 0.20% — 6.00% to 5.80%.
- 2025: cut of 0.50% — 5.80% to 5.30%.
Flat-tax conversion, 2023. Idaho replaced a graduated schedule topping out at 6.00% with a single rate of 5.80%, and has kept a single rate since. A flat rate cuts the top bracket and can raise the rate on the lowest incomes at the same time; this page shows only the top.
What this page does not tell you
This is the top marginal rate, not anyone's bill. Only the rate is carried back; Idaho's brackets, standard deduction and exemptions for years before 2025 are not in this dataset. A cut in the top rate can sit alongside a higher bill for most filers.
Only the top marginal rate is carried back. Brackets, deductions and exemptions for years before 2025 are not in this dataset.
Years before 2025 are Tax Foundation's 1 January snapshot; 2025 and 2026 are the rate enacted for the whole year, from the state's own source. Where the two disagree the record carries both figures.
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