Idaho property tax: how it works and what the homestead saves

Who sets your property tax?

Two kinds of bodies are involved.

• The county assessor values your home. Idaho law requires property to be assessed at market value for assessment purposes as of 12:01 a.m. on January 1 of the year the tax is levied (Idaho Code § 63-205).
• Local taxing districts set the money they need. In Ada County, the 2025 levy certificate lists the county, the City of Boise, school districts, the highway district, fire, library and other districts. Your tax bill adds up the levies of every district your home sits in.

The formula is: (assessed value minus exemptions) x total levy rate. A levy rate is written as dollars per dollar of value, so 0.009202233 means about $9.20 per $1,000.

How big is the homeowner’s exemption?

The exemption is the first $125,000 of the home’s market value, or 50% of it, whichever is less (Idaho Code § 63-602G(1)). A $200,000 home therefore gets a $100,000 exemption, and any home worth $250,000 or more gets the full $125,000.

To qualify, you must meet these conditions (§ 63-602G(2); § 63-701(2)):

• The home is owner-occupied and your primary dwelling.
• The exemption covers the dwelling and up to one acre of surrounding land that is reasonably necessary for its use.
• You certify that you have not claimed the exemption on another homestead.
• You apply to the county assessor. An owner has to apply only once, as long as the same owner keeps living in the same home (§ 63-602G(4)).

Some official pages still show older figures. The City of Boise’s property tax page, for example, mentions $100,000. The current statute says $125,000, and so does the Ada County Assessor.

What are the limits on tax increases?

Idaho does not cap the increase in your individual assessment. It caps the budgets of taxing districts instead. Under Idaho Code § 63-802, a taxing district generally cannot certify a property tax budget above its highest amount of the previous three years plus a growth factor of up to 3%, plus revenue from new construction and annexation. The total increase generally cannot exceed 8% (15% for fire protection and ambulance districts). School district levies approved under § 33-802 are outside this rule, and voters can approve bonds and special levies.

Help for seniors, widows and others: the Property Tax Reduction program

Idaho’s “circuit breaker” program reduces property tax on a home and up to one acre by as much as $1,500. It is for owner-occupants who are 65 or older, disabled, blind, widows or widowers, former prisoners of war, or fatherless or motherless children under 18, and whose income is under a limit. For 2025, total 2024 income after deducting medical expenses had to be $37,810 or less (Tax Commission Pub. 135). The limit changes each year. You apply through the Ada County Assessor between January 1 and April 15 and must reapply every year.

When to apply, appeal and pay

Two details matter. First, an exemption application received after the second Monday in July is granted as a tax cancellation instead (§ 63-602G(5)). Second, an appeal to the Board of Tax Appeals or the district court does not suspend payment of the taxes (§ 63-511).

The Ada County Assessor says an appeal to the board addresses only the market value of your property, not the amount of the tax. Typical evidence is sales of comparable homes or an independent appraisal.

Example: a $500,000 home in Boise

This is an illustration, not a quote. It assumes the home sits in Ada County code area 01-1 (Ada County, emergency medical, Ada County Highway District, Boise School District No. 1, City of Boise and College of Western Idaho) and is the owner’s primary home. It uses the 2025 levies certified by Ada County. Your code area may include other districts, such as an urban renewal district or a voter-approved bond.

Taxable value: $500,000 minus the $125,000 exemption = $375,000.

Without the exemption, the same home would owe $4,601.12, so the exemption saves $1,150.28. Costs billed with the property tax but not set by levy, such as solid waste or irrigation fees, are not included.

For the one-time costs at purchase, see closing costs in Idaho. For city detail, see the Boise guide. If your lender pays the bill for you, see escrow accounts.