What is the property tax rate in Bonneville County?

The combined effective property tax rate in Bonneville County, Idaho is approximately 0.66%.

Bonneville County Property Tax Calculator (2026)

Property Tax in Bonneville County, 2026

A calculator and field guide for Idaho Falls-area homeowners — and for anyone considering a move to Bonneville County — including Idaho's 100% assessment ratio, the $125,000 Homestead Exemption (Idaho Code §63-602G — lesser of $125K or 50% of MV), the HB 292 of 2023 Homeowner Property Tax Relief Account (state-funded ~$200-500/yr automatic credit, made permanent at $50M/yr by HB 304 of 2025), the parallel School District Facilities Fund ($50M/yr state payment of eligible school bond debt), the Property Tax Reduction (Circuit Breaker §63-705) for 65+/widowed/disabled with HHI ≤ $39,130 ($250-$1,500 refundable), and the $1,500 Veterans Property Tax Reduction (NOT full — Idaho is NOT a categorical full-vet state).

Bonneville County operates under Idaho's 100% assessment ratio + $125,000 Homestead Exemption system (Idaho Code §63-602G). Owner-occupied primary residences receive an exemption equal to $125,000 OR 50% of market value, whichever is LESSER, applied as a reduction in taxable value. Bonneville's combined mill levy is approximately 10.34 mills per $1,000 of taxable value, producing typical homestead effective rates around 0.66%. HB 292 of 2023 adds a state-funded credit (~$200-500 typical) automatically on the December tax bill.

How the bill is built

Idaho is a 100% AR state — the assessor sets market value with no AR reduction. For owner-occupied homesteads, subtract $125,000 OR 50% of MV (whichever is lesser) to get taxable value. A $400K homestead: TV = $275K. A $200K homestead: TV = $100K (50% cap). Tax = TV × combined mill levy / 1000. State credits (HB 292, PTR Circuit Breaker, Veterans Reduction) apply to the bill after calculation. Bills issue in November, half due Dec 20 and half June 20.

HB 292 of 2023 was Idaho's response to the 2020-2022 housing boom. Two state-funded mechanisms apply automatically to homesteads: the Homeowner Property Tax Relief Account (~$200-500 December bill credit) and the School District Facilities Fund (state pays eligible school bond debt). HB 304 of 2025 made both permanent at $100M/year combined.

Idaho is NOT a full-vet-exemption state. The Veterans Property Tax Reduction (Idaho Code §63-701) caps at $1,500/year for 100% P&T or IU disabled vets — no income limit, but the ceiling means high-bill Boise/CDA homestead owners still pay the difference. Stack with the $125K Homestead Exemption + HB 292 credit for compounded benefit.

2026 Bonneville County rate breakdown (combined mill levy per $1,000 of taxable value (100% AR; FMV − $125K Homestead Exemption); HB 292 Homeowner Tax Relief Credit ~$200-500 applied post-bill, Idaho Falls district)

Taxing entity	Rate
Bonneville County combined mill levy (county + city + school district + highway district + library district); typical Idaho Falls residential tax code area, post 100% AR + $125K Homestead Exemption	10.3400
Combined total	10.3400

As of April 27, 2026 · From Bonneville County Assessor.

Note: Bonneville County is the regional commercial and economic anchor for eastern Idaho — Idaho Falls (~67,000) is the largest city in the eastern half of the state. The county sits on the Snake River Plain at the western edge of the Yellowstone region (~90 miles to West Yellowstone) and the southern edge of the Teton range. Idaho Falls Regional Airport (IDA) is the primary commercial airport for southeast Idaho, western Wyoming, and southern Montana — including Yellowstone NP visitors flying in for the western entrance gateway communities.

Note: Bonneville’s 0.66% effective rate reflects Idaho Falls-area mill levies around 10.34 per $1,000 of taxable value applied to a $345,000 median homestead with $125,000 Homestead Exemption. Net taxable value of $220,000 produces typical bills of ~$2,275 — among the lowest absolute bills in Idaho’s major counties due to lower median home values. Eastern Idaho generally has lower home values than the Boise/Coeur d’Alene boom regions, and saw less dramatic 2020-2022 appreciation (~50% in Idaho Falls vs ~85-95% in Boise/CDA).

Note: Idaho National Laboratory (INL) — operated for the US Department of Energy by Battelle Energy Alliance — sits on an 890-square-mile reservation on the Snake River Plain west of Idaho Falls. INL is one of the DOE’s premier nuclear research facilities; ~6,000 employees commute daily from Idaho Falls (the workforce is bused on dedicated INL bus routes). The reservation hosted EBR-I (Experimental Breeder Reactor I) — the world’s first nuclear reactor to generate electricity, which lit four 200-watt bulbs on December 20, 1951. The site has hosted 50+ test reactors over its history. INL is also the site of the SL-1 reactor accident on January 3, 1961 — the only fatal nuclear reactor accident in US history (3 military operators killed).

Deductions and exemptions for 2026

Idaho homeowner relief operates through four mechanisms: the $125,000 Homestead Exemption (applies automatically to all primary residences), HB 292's Homeowner Tax Relief Credit (state-funded, ~$200-500 automatic), the Property Tax Reduction Program / Circuit Breaker (income-tested, $250-$1,500 for 65+/widowed/disabled), and the Veterans Property Tax Reduction (up to $1,500 for 100% disabled vets, no income limit). Idaho is NOT a full-vet-exemption state — the $1,500 ceiling matters for high-bill homesteads.

Homestead Exemption (Idaho Code §63-602G)

Reduces taxable value by the LESSER of $125,000 OR 50% of market value, for owner-occupied primary residences. Examples: $400K home → $125K exemption (cap), TV = $275K. $200K home → $100K exemption (50% cap), TV = $100K. Apply with County Assessor; the homestead must be owner-occupied as primary dwelling on January 1 (or before April 15 if purchased after; later filings prorate). One-time application — auto-renews unless ownership or residency changes. Raised from $100K to $125K effective Jan 1, 2022 (HB 389 of 2021).

HB 292 of 2023 Homeowner Property Tax Relief Account

State-funded direct credit applied automatically to the December tax bill on all homestead-exempted properties — no application required. Typical reduction $200-500/year. HB 304 of 2025 made the funding permanent at $50M/year, plus another $50M/year to a parallel School District Facilities Fund that pays eligible school bond debt (reducing the school levy portion for all property owners with eligible bonds). The credit was Idaho's response to the 2020-2022 housing boom that drove Treasure Valley and Coeur d'Alene home values up 80-100%.

Property Tax Reduction Program (Circuit Breaker, Idaho Code §63-705)

Refundable credit of $250-$1,500 for homeowners 65+ OR widowed OR disabled OR blind OR former POW/hostage with 2025 income (after medical expenses) ≤ $39,130 for 2026 tax year. Home value cap: market value ≤ 200% of county median assessed value. Apply with County Assessor or Idaho State Tax Commission between Jan 1 and Apr 15; annual application required. New online portal at the Tax Commission since 2024. A separate Property Tax Deferral program (income limit ~$61,674) lets seniors defer with a state lien repaid at sale.

Veterans Property Tax Reduction (Idaho Code §63-701 et seq.)

Up to $1,500 maximum tax credit for veterans with 100% service-connected disability OR 100% individual unemployability rating. NO income limit. Apply by April 15 with County Assessor or Idaho State Tax Commission; submit VA disability rating letter + DD-214. P&T disabled: one-time application, auto-renews. Non-P&T 100% disabled / IU: annual application required. Stacks with Homestead Exemption + HB 292 credit — a 100% disabled vet in Boise can bring a typical ~$3,800 bill down to ~$1,800-2,100.

Appealing your assessment

Assessment notices are mailed in early June. Contact the County Assessor's office immediately to request informal review; if unsatisfied, file formal appeal with the County Board of Equalization no later than the FOURTH MONDAY OF JUNE (Idaho Code §63-501A). The BOE meets July-August. Appeal further to the Idaho Board of Tax Appeals within 30 days, then District Court. Idaho's tight ~3-week appeal window catches many homeowners off guard — assessment notices arrive early June and BOE deadline is fourth Monday of June.

Cities and towns in Bonneville County

Bonneville County contains 4 incorporated municipalities, ranging from Idaho Falls to the smallest village. Search volume for property tax is often city-specific, so here is the complete list — with population from the 2020 US Census, rounded to the nearest 100.

Data: US Census Bureau, 2020 Decennial Census. Populations rounded. Cities marked as "split" straddle a county border — the portion inside Bonneville County is subject to Bonneville County's tax rolls, while the portion outside is subject to the adjacent county's.

City or town	Type	Population (2020)
Idaho Falls County seat	city	67,000
Ammon	city	18,000
Iona	city	3,000
Ucon	city	1,300

About city-level property tax rates: The rate breakdown and calculator on this page reflect the Idaho Falls tax district. Other cities in Bonneville County may pay into different school districts, city rates, and special districts — so their combined rates can differ, sometimes substantially. Always verify the specific rates for your address with the Bonneville County Assessor before relying on any estimate.

Frequently asked questions

When are Idaho property taxes due?

Bills are issued in November by the county treasurer. Most counties allow split-payment: first half due December 20, second half due June 20. Late payments accrue 1% per month + 2% penalty. Most homeowners pay through escrow. The HB 292 credit applies automatically to the December bill if your homestead exemption is on file with the County Assessor.

How does Idaho's $125,000 Homestead Exemption work?

The exemption (Idaho Code §63-602G) reduces taxable value by the LESSER of $125,000 OR 50% of market value. A $400K home: $125K exempt, TV = $275K. A $200K home: $100K exempt (50% cap), TV = $100K. Apply once with the County Assessor — auto-renews unless ownership or residency changes. Idaho is a 100% AR state, so the exemption directly reduces taxable value (no AR layer).

What is HB 292 of 2023?

HB 292 was Idaho's response to the 2020-2022 housing boom. It created two state-funded mechanisms: a Homeowner Property Tax Relief Account (~$200-500 automatic credit on the December bill for all homestead-exempted properties) and a School District Facilities Fund (state pays eligible school bond debt, reducing the school levy for all owners with eligible bonds). HB 304 of 2025 made both permanent at $100M/year combined. No application required.

How does the Property Tax Reduction (Circuit Breaker) work?

Refundable credit of $250-$1,500 for homeowners 65+ OR widowed OR disabled OR blind OR former POW with 2025 income (after medical expenses) ≤ $39,130 for 2026. Home value cap: market value ≤ 200% of county median assessed value. Apply with County Assessor or Idaho State Tax Commission between Jan 1 and Apr 15; annual application required. Sliding scale by income — lowest-income filers get the full $1,500.

Why isn't Idaho a full-vet-exemption state?

The Veterans Property Tax Reduction (Idaho Code §63-701) is a $1,500 maximum credit, not a full exemption. A 100% disabled veteran in Boise with a typical ~$3,800 bill still owes ~$2,300 after the credit; in lower-bill rural counties (Bingham ~$1,500), the $1,500 credit approximates full exemption. The benefit has NO income limit (unlike the senior PTR Circuit Breaker), and stacks with the $125K Homestead Exemption + HB 292 credit. Apply by April 15.

About Bonneville County

Beyond the property tax — a few things you might not know about the place.

Weird fact

The SL-1 reactor accident at Idaho National Laboratory (then called the National Reactor Testing Station) on January 3, 1961 remains the only fatal nuclear reactor accident in United States history. Three Army operators — John Byrnes, Richard Legg, and Richard McKinley — were killed when a control rod was withdrawn too far during routine maintenance, causing a steam explosion that killed all three within seconds. McKinley’s body remained in the reactor vessel for 6 days before recovery (it was so radioactive it had to be buried in lead). The cause remains officially "operator error" but fringe theories suggest a murder-suicide by Byrnes (some accounts allege Byrnes had personal conflicts with Legg over Byrnes’s wife). The SL-1 victims are buried at Arlington National Cemetery in lead-lined coffins.

Hometown hero

Philo Farnsworth

The American inventor (1906-1971) — born in Beaver, Utah but spent ages 12-19 in Rigby, Idaho (just north of Idaho Falls in adjacent Jefferson County) where he conceived the idea of electronic television at age 14 while plowing potato fields in 1921. Farnsworth produced the first electronic television image in San Francisco on September 7, 1927 — at age 21 — using an "image dissector" tube he had designed in his Idaho farm-boy notebook. His invention is the foundation of all modern electronic display technology. Rigby, Idaho proudly claims the title "Birthplace of Television" — a high school memorial and the Jefferson County Historical Museum chronicle Farnsworth’s connection. Farnsworth lost a long patent battle with RCA over television priority despite eventually winning royalties; he died destitute in Salt Lake City.

Biggest annual event

Eastern Idaho State Fair

Held annually for 8 days in early September at the Eastern Idaho State Fairgrounds in Blackfoot (in adjacent Bingham County, ~30 miles from Idaho Falls) since 1902, the Eastern Idaho State Fair draws ~250,000 attendees from a multi-state region (eastern Idaho + western Wyoming + southwestern Montana). Idaho Falls hosts the Idaho Falls Chukars Pioneer League baseball team (Class A affiliate of the KC Royals from 2004-2020, now an independent partner team). The Idaho Falls Symphony performs at the Civic Auditorium (built 1952). The Idaho Falls River Walk along the Snake River features the dramatic Idaho Falls themselves — a series of artificial waterfalls created when the Snake River was channeled through downtown for hydroelectric generation in the early 1900s.

Property Tax in Bonneville County, 2026