Moving From Idaho Tax Guide 2026: 5.3% Flat Rate, Low Property Tax & a Food Tax Credit

Idaho's move from graduated brackets to a flat income tax was one of the most significant state tax simplifications in recent years: the 2022 schedule still had four brackets (1% to 6%), while 2023 introduced a single flat 5.8% rate, cut to 5.695% for 2024 and to 5.3% for 2025 (House Bill 40, signed March 2025). The 5.3% rate still applies for 2026. That made Idaho more competitive with neighboring Nevada (no income tax) and puts it close to Montana, whose 2026 rates are 4.7% and 5.65%. Idaho's low property taxes (~0.63%), no estate tax, and low cost of living outside of Boise make it an overall moderate-tax state. The notable exception for retirees: Idaho's retirement benefits deduction covers only specific plans, so most private pension and IRA income is fully taxed. This guide covers what Idaho residents considering a move need to know.

Idaho's 2022 Tax Reform and Current Competitiveness

Idaho's move from graduated brackets to a flat tax (from tax year 2023), followed by rate cuts in 2024 and 2025, made Idaho significantly more competitive with neighboring states.

Before and After Reform

Idaho's 2022 rate schedule had four brackets (1%, 3%, 4.5% and 6%). For 2023 the state switched to a single 5.8% flat rate above a small zero-rate bracket, then cut it to 5.695% for 2024 and to 5.3% for 2025 (House Bill 40, signed by Governor Brad Little in March 2025). The rate is still 5.3% for 2026.

Idaho vs Nevada and Wyoming

For a single Idahoan earning $100,000 in 2026: $100,000 less the $16,100 federal standard deduction is $83,900 of Idaho taxable income; after the $4,811 zero-rate bracket (2025 schedule), 5.3% applies to $79,089, or about $4,192 in Idaho income tax. Nevada income tax: $0. Wyoming income tax: $0. Annual income tax savings by moving to Nevada or Wyoming: about $4,192. Against Idaho's low cost of living (especially outside Boise), low property tax, and no estate tax, the financial case for leaving Idaho is meaningful but not dramatic for most middle-income residents. The strongest case: high earners with significant investment income or business income (Idaho taxes most capital gains at the same 5.3% flat rate; only gains from the sale of certain qualified Idaho property qualify for a 60% deduction).

Boise's Growth and Property Tax Pressure

Boise became one of the fastest-growing metros in the US through 2020–2023, with home values roughly doubling. Even at Idaho's low 0.50% effective rate, rising assessed values have pushed nominal property tax bills up significantly. The Idaho legislature has periodically provided homeowner relief but has not fundamentally reformed the property tax structure. For Boise homeowners, property tax is increasingly a material budget item despite the low effective rate.

Military Retirees: Idaho vs Neighbors

Idaho does not fully exempt military retirement pay, but its retirement benefits deduction is available to retired service members who are disabled, age 62 or older, or under 62 and employed with enough income to be required to file a federal return. For a retired service member age 62 or older receiving $50,000 a year in military retirement pay and no Social Security, the deduction (up to $48,216 for a single filer in 2025) leaves about $1,784 of that pay taxable, before the standard deduction. Montana lets working military retirees subtract the lesser of 50% of military retirement income or their Montana-source earned income; Nevada and Wyoming have no income tax.

Idaho Residency Exit Rules

Idaho uses domicile-based residency with a 270-day (9-month) alternative test:

Idaho Residency Definition

Idaho defines a resident as someone domiciled in Idaho, or a non-domiciliary who maintains a home in Idaho and is present in Idaho for more than 270 days during the tax year. The 270-day test is higher than the more common 183-day standard, giving part-time residents more flexibility. To exit Idaho residency: establish domicile in the new state (driver's license, voter registration, primary home), change vehicle registration, update estate documents. Idaho does not have an aggressive post-departure audit reputation.

Part-Year Returns

In your departure year, file Idaho Form 43 (part-year resident return) covering income earned during Idaho residency. Idaho-source income after departure (Idaho rental income, Idaho business income) remains taxable as non-resident income. Idaho's low 0.63% property tax on any retained Idaho real estate is a modest ongoing obligation.