Ada Property Tax: Rates, Exemptions & Appeals (2026)

Ada County’s regular 2026 property-assessment appeal deadline was Monday, June 22, 2026, by 5:00 p.m.—the fourth Monday in June. Appeals are filed with the Ada County Commissioners’ Office / Ada County Board of Equalization, not the Assessor: 200 W. Front St., 3rd Floor, Boise, ID 83702; phone 208-287-7000; fax 208-287-7009; email bocc1@adacounty.id.gov. As of August 23, 2026, that primary-roll deadline has passed; the next normal primary-roll deadline is expected to be Monday, June 28, 2027, while unusual subsequent-roll assessments use the fourth Monday in November.

How assessments work in Ada County

Ada County does not reassess on a multi-year cycle. The Assessor estimates the full market value of real property every year, with a statutory value date of January 1. Your assessment notice is the Assessor’s estimate of what the property could have reasonably sold for on the open market as of January 1, not what your tax bill will be.

The Assessor’s assessment-notice guide says the notice shows the total value, any homestead exemption, prior values and taxes, taxing district information, your appraiser’s contact information, and the appeal deadline. Ada County’s budget materials describe the appraisal division as sending market-value estimates to all property owners in late May, answering taxpayer questions in June, physically re-inspecting at least 20% of the county annually, and using market analyses for trending.

That timing matters. Your 2026 appeal should have been about the January 1, 2026 market value. Sales after January 1 can still be useful background, but your strongest evidence is usually closed sales near January 1, 2026, for similar homes in the same Boise, Meridian, Eagle, Kuna, Garden City, Star, or unincorporated Ada County market area.

Your tax bill is separate. After assessments and exemptions are finalized, each taxing district sets its budget and levy. The Treasurer then applies your parcel’s combined levy rate to taxable value. Two homes with the same assessed value can have different bills if they sit in different code areas, school zones, fire districts, library districts, or urban-renewal areas.

Whether you should appeal

Appeal when the market value is wrong, not just because taxes feel high. The Board of Equalization cannot reduce school, city, highway district, library, or county budgets during your value hearing. It decides whether the assessed value or exemption decision is correct.

Start with three checks:

1. Property facts. Use Ada County’s Property Search / Online Maps and compare the record to your home: finished square footage, basement, lot size, garage, year built, remodel quality, outbuildings, and condition. A factual error can sometimes be corrected by the appraiser without a formal hearing.
2. Comparable sales. Find sales of similar homes that closed before or close to January 1, 2026. Use similar location, size, age, condition, lot utility, view, and school/amenity influence. Listings and asking prices are weaker than closed sales.
3. Condition evidence. If your home needs a roof, has foundation issues, water intrusion, deferred maintenance, or unpermitted/nonfunctional space, gather photos, contractor bids, inspection reports, or an appraisal.

Do not invent a “success rate.” I found no official Ada County publication giving a homeowner appeal success rate, median reduction, or average reduction. Treat any private-company savings statistic as marketing unless it links to county-level public data.

A realistic savings example: suppose a Meridian owner-occupied home in a common 2025 Meridian code area has a combined levy rate around 0.004507 and is assessed at $500,000. With the Idaho homeowner’s exemption capped at $125,000, taxable value is about $375,000. If the Board lowers the assessed value to $465,000, taxable value becomes $340,000. Estimated annual savings: $35,000 × 0.004507 = about $158. Your rate may be higher or lower depending on your parcel’s code area, so use your own tax bill or the Treasurer’s lookup for a precise estimate.

Step-by-step how to file

1. Read the notice immediately. The notice prints your appraiser’s name, phone/email, and the appeal deadline. For 2026 primary-roll residential assessments, Idaho’s fourth-Monday rule made the deadline June 22, 2026, by close of Ada County business, 5:00 p.m.

2. Call or email the appraiser first. Ada County specifically recommends contacting the appraiser before filing. If you show a data error or strong market evidence early, the appraiser may adjust the value before BOE.

3. Use the official form. The form name is Property Assessment Appeal Form. Forms are available through the Ada County Commissioners’ property assessment appeals page and the Assessor’s assessment notices/appeals resources. If someone else will appear, file, or testify for you, use an agent/representative authorization or notarized owner authorization if required by the form instructions. Exemption disputes use the county’s property-tax exemption appeal materials.

4. Attach evidence. Include the current assessment notice, comparable-sales grid or CMA, appraisal if you have one, photos, repair bids, and a short written explanation of the value you believe is correct. Keep it focused: “Three similar homes sold for $455k–$470k before January 1; my home is smaller and needs a roof; requested value $465,000.”

5. File with the Commissioners / BOE—not the Assessor. Filing methods published for Ada County include:

• In person: Ada County Commissioners’ Office, 200 W. Front St., 3rd Floor, Boise, ID 83702.
• Mail: same address. Use a trackable service and do not wait until deadline day.
• Email: bocc1@adacounty.id.gov.
• Fax: 208-287-7009. Confirm receipt because deadline-day volume can be risky.
• Portal: Ada County has online property search tools, but I found no official dedicated online assessment-appeal filing portal for BOE appeals.

Ada County does not publish a county filing fee for a normal assessment appeal; the Idaho Board of Tax Appeals also states there is no fee for BTA appeals.

What happens after

The proper hearing authority is the Ada County Board of Equalization, which is the Board of Ada County Commissioners sitting as the BOE. Idaho law has the BOE period running from the fourth Monday in June until the second Monday in July for primary-roll work.

On Ada County’s own appeal guide, you must choose whether you want oral testimony. If you select No or leave that section blank, your written appeal and documents go into the record and the Board reviews them without scheduling you for oral testimony. If you select Yes, a hearing is scheduled. Hearings are scheduled in the order applications arrive and generally cannot be changed.

Ada County describes residential hearings as short—often an 8- to 10-minute window. The owner presents first, typically up to three minutes. The Assessor’s appraiser then presents the county’s evidence, and the owner gets a short rebuttal/conclusion. The burden is on you to show the Assessor’s value is wrong. Be concise and bring copies organized by parcel number.

The Board deliberates and makes a decision as part of the BOE process. If you disagree, the next step is an appeal to the Idaho Board of Tax Appeals or district court. The BTA states BOE decisions on valuation or exemption are generally appealable within 30 days after the BOE decision is mailed, pronounced at hearing, or the BOE fails to act.

Local tips

• Check the homestead/homeowner’s exemption before appealing value. Ada County’s homeowner exemption can remove 50% of assessed value up to the state cap, currently $125,000, for an owner-occupied primary residence and up to one acre. Missing it can cost more than a small value appeal saves.
• For 2026 relief programs, April 15 was the key date. Idaho’s Property Tax Reduction program could reduce taxes by $250–$1,500 for qualifying homeowners with 2025 income after medical deductions of $39,130 or less, and qualifying status such as age 65+, widow(er), blind, disabled, former POW/hostage, or qualifying minor child.
• 100% service-connected disabled veterans should check the veteran reduction. Ada County says the program can reduce taxes by up to $1,500 and requires a current homeowner’s exemption; qualifying 100% permanently and totally disabled veterans may not need to reapply annually unless they change homesteads.
• Deferral is not forgiveness. Idaho’s 2026 deferral program lets qualifying homeowners defer taxes if 2025 income was $61,674 or less, but deferred taxes become a lien and must be repaid.
• Use neighborhood-specific comps. A Boise North End bungalow, a Meridian subdivision home, and an Eagle acreage are not interchangeable just because the square footage is similar.
• File early. If you file on the last day, your hearing can come quickly, leaving little time to organize evidence or ask the appraiser to review your packet.

Ada County Property Tax Rate

No single countywide millage was verified. The latest official Idaho State Tax Commission county average report shows Ada County 2025 average property tax rates based on levied amounts of 0.652% urban, 0.560% rural, and 0.642% overall.

Source: https://tax.idaho.gov/document-mngr/reports_epb00129/

When Are Property Taxes Due in Ada County?

Property tax payments are due December 20; taxpayers may pay the full amount by December 20 or pay half by December 20 and the balance by June 20 of the following year. Two-payment option: pay one-half by December 20 and the remaining one-half by June 20 of the following year.

This is not the same as the assessment appeal deadline above. The appeal deadline is your window to contest your assessed value; the payment due date is when the resulting tax bill must be paid. Missing one does not affect the other, but missing either has real consequences — one forfeits your right to appeal for the year, the other can trigger penalties and interest.

Source: https://tax.idaho.gov/taxes/property/understanding-property-taxes/

Property Tax Exemptions in Ada County

• Homeowner’s Exemption — Idaho homeowners who own and occupy a home, including a manufactured home, as their primary residence; the exemption applies to the home and up to one acre of land.. Exempts 50% of the value of the home and up to one acre of land, up to a maximum exemption of $125,000. Yes, apply with the county assessor; once approved, the exemption lasts until ownership changes or the home is no longer used as the primary residence. Apply by Apply before December 31 to qualify for that specific tax year.. (Source: https://tax.idaho.gov/search-category/property-tax/homeowners/)
• Property Tax Reduction Program / Circuit Breaker — For 2026, Idaho resident homeowners with 2025 income after medical-expense deductions of $39,130 or less who owned and lived in the home before April 15, 2026, have a current homeowner’s exemption, and are 65 or older, blind, widowed, disabled, a former POW/hostage, or a motherless/fatherless child under 18.. Reduces property taxes on the home and up to one acre of land by $250 to $1,500; does not reduce solid waste, irrigation, or other government fees. Yes, apply every year with the county assessor or online through the Idaho State Tax Commission. Apply by 2026-04-15. (Source: https://tax.idaho.gov/search-category/property-tax/homeowners/)
• Property Tax Deferral Program — For 2026, Idaho resident homeowners with 2025 income of $61,674 or less who meet the program conditions; the program applies to the home and up to one acre of land.. Postpones payment of property taxes on the home and up to one acre of land; deferred taxes and interest must be repaid later and the program does not defer solid waste, irrigation, or other government fees. Yes, apply and qualify every year with the county assessor or online through the Idaho State Tax Commission. Apply by 2026-09-08. (Source: https://tax.idaho.gov/search-category/property-tax/homeowners/)
• Disabled Veterans Property Tax Benefit — For 2026, Idaho resident homeowners who are qualified veterans recognized by the U.S. Department of Veterans Affairs as 100% service-connected disabled or receiving 100% compensation due to individual unemployability as of January 1, 2026; they must own and live in the home before April 15, 2026, and have a current homeowner’s exemption.. Reduces property taxes on the home and up to one acre of land by as much as $1,500; no income limit; does not reduce solid waste, irrigation, or other government fees. Yes, apply every year unless the disability is permanent and total, in which case the benefit renews automatically after approval. Apply by 2026-04-15. (Source: https://tax.idaho.gov/search-category/property-tax/homeowners/)

How to Look Up Your Property Record in Ada County

You can look up your property's official record at https://www.adacountyassessor.org/adamaps/. Ada County Assessor’s online GIS/property information system provides official parcel/property data used for assessment purposes, including parcel characteristics and assessed values.