Custer County, ID Property Tax: $903/yr (2026)
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The effective property tax rate in Custer County is 0.31% of assessed home value. On a home at the county median value of $295,600, that works out to about $916 per year, or $76 per month. Custer County is located in central Idaho, with Challis as its county seat, and is home to approximately 4,411 residents.
About Custer County
Custer County covers approximately 4,922.2 square miles in Idaho. The county is home to about 4,411 residents living in roughly 3,164 housing units, of which 47.4% are owner-occupied. The median household income is $56,957, and the median home was built in 1987.
The county seat is Challis. Custer County borders Blaine County, Boise County, Butte County, Elmore County, Lemhi County — useful comparisons if you're considering nearby areas with potentially different tax rates.
How Property Taxes Work in Idaho
Property taxes in Idaho are administered at the county level. Each county sets a millage rate applied to the assessed value of real property — the effective rate above accounts for any partial assessments and exemptions already built into the local tax base. Assessed value can differ meaningfully from current market value depending on how often the county reassesses and what fraction of market value it uses.
Most counties in Idaho offer exemptions that reduce the taxable assessed value: homestead exemptions for primary residences, senior exemptions, disability exemptions, and veteran exemptions are common. These reduce your effective rate below the county-wide average shown here. Contact the Custer County Assessor's office to learn which exemptions apply to your property and when to file.
Custer County vs. Neighboring Counties
| Location | Eff. Rate | Median Home | Annual Tax |
|---|---|---|---|
| Custer County, ID | 0.31% | $295,600 | $916 |
| Idaho state average | 0.51% | — | $1,508* |
| Blaine County | 0.39% | $663,800 | $2,563 |
| Boise County | 0.37% | $424,100 | $1,571 |
| Butte County | 0.50% | $195,800 | $986 |
| Elmore County | 0.60% | $278,300 | $1,680 |
| Lemhi County | 0.39% | $282,100 | $1,109 |
| US national average | 1.10% | $281,900 | $3,101 |
*State average annual tax computed at Custer County's median home value of $295,600. Source: US Census ACS 2023 5-year estimates.
Frequently Asked Questions
How does Custer County's property tax rate compare to the rest of Idaho?
At 0.31%, Custer County is lower than the Idaho state average of 0.51%. On a home at the county median of $295,600, that means about $916 per year — versus $1,508 at the state average rate, a difference of $592 per year. Compared to the national average of 1.10%, Custer County is below average.
What's a typical annual property tax bill in Custer County?
For a home at the county median value of $295,600, the annual property tax in Custer County is approximately $916 — or about $76 per month. For a home worth $443,400, expect around $1,375 per year. For a $591,200 home, approximately $1,833 per year. Use the calculator above to estimate taxes for any assessed value.
Where do I appeal a Custer County property tax assessment?
Property assessment appeals in Custer County are handled by the Custer County Assessor's office in Challis. Most jurisdictions require filing within 30–90 days of receiving your assessment notice — confirm the specific deadline with the assessor's office before submitting, as deadlines and procedures vary by county. A successful appeal can reduce your assessed value and lower your tax bill for the current and future tax years.
What exemptions are available in Custer County?
Idaho counties commonly offer homestead exemptions for owner-occupied primary residences, senior citizen exemptions for qualifying homeowners aged 65 and older, exemptions for disabled residents, and veterans' exemptions. Each exemption reduces your assessed taxable value, which in turn reduces your effective tax rate below the county-wide 0.31% shown here. Contact the Custer County Assessor's office to confirm which exemptions are available and the application deadlines.
Data sources: US Census Bureau ACS 2023 5-Year Estimates, US Census Gazetteer (2024), County Adjacency File