Boulder County Property Tax Appeal, Colorado

Rob Hartley·Updated May 15, 2026

Boulder County is located along Colorado's Front Range with the city of Boulder serving as the county seat, and includes notable cities such as Longmont, Louisville, Lafayette, Superior, and Erie. The median Boulder County effective property tax rate is 0.50%, significantly lower than the national median of 1.02%, with a median annual tax bill of $3,545, which is $1,145 higher than the national median property tax bill of $2,400. According to U.S. Census Bureau ACS 5-year data, the median home value in Boulder County is approximately $713,900 with median owner-occupied real estate taxes of $3,821, an implied effective rate of about 0.54%. Because Boulder County home values are well above state and national averages, even a modest over-assessment can result in hundreds of dollars in excess taxes annually, making appeals particularly worthwhile here.

Notable cities: Boulder, Longmont, Louisville, Lafayette, Superior, Erie, Nederland

Median Home

$713,900

Tax Rate

0.54%

Annual Tax

$3,821

On the typical Boulder County home, valued near $713,900 at the county’s effective tax rate of 0.54%, an over-assessment of even 10% means you are overpaying year after year until you appeal it. Here is how to find out if yours qualifies.

2026 Appeal Deadline: June 8, 2026

Appeals of real property values can be filed with the Assessor between May 1 and June 8. Deadlines for appeal are strictly enforced. Property owners will receive a Notice of Value (NOV) around May 1.

See if your Boulder County home is over-assessed

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Property in Boulder County, Colorado, local tax assessment and appeal guide

How Boulder County Assesses Property

6.7%of market value

Assessed by: Boulder County Assessor's Office

Assessment cycle: biennial

Notices typically mailed: Early May (by May 1)

Colorado statute requires that each property in the county be re-valued by the County Assessor in odd numbered years , with the assessed value calculated by multiplying actual market value by the residential assessment ratio. For example, if your Boulder County home has a market value of $713,900, at Colorado's 6.7% assessment ratio your assessed value would be approximately $47,831, resulting in roughly $3,855 in annual taxes at the county's effective rate of 0.54%. Beginning in tax year 2025 (payable in 2026), there are two assessment rates; one for school districts and one for all other local government districts (fire districts, cities, etc.).

The Appeal Process

Appeals are heard by the County Board of Equalization. If your appeal goes to a hearing, you'll typically have 5-15 minutes to present, so organize your evidence clearly, practice your key points, and prepare to answer questions about your property value.

Review your Notice of Valuation (NOV) mailed around May 1 and verify the property characteristics, square footage, and classification for accuracy.

Research comparable sales using the Assessor's Comparable Sales Lists with Time Trending and Lookup Tool, focusing on sales between July 1, 2022 and June 30, 2024.

File your real property appeal with the Boulder County Assessor between May 1 and June 8, 2026, either online via Just Appraised, by mail to PO Box 471, or in person at 1325 Pearl Street.

Receive the Notice of Determination (NOD), which the Assessor must mail by August 15 with the results of your appeal.

If you disagree with the determination, file a written appeal with the County Board of Equalization (CBOE) on or before September 15.

Attend your CBOE hearing and present comparable sales, photos, and evidence supporting a lower value.

If still unsatisfied, within 30 days of the CBOE decision you may appeal to the Colorado Board of Assessment Appeals, request binding arbitration, or file in District Court.

Required form: Real Property Appeal Form (included with the Notice of Valuation)

Filing Methods

online:https://bouldercounty.gov/property-and-land/assessor/appeals/ - file via Just Appraised online portal (account required)

mail:Boulder County Assessor, PO Box 471, Boulder, CO 80306-0471

in-person:1325 Pearl Street, 2nd floor, Boulder, CO 80302, or drop in an Assessor's Drop box

Evidence to Bring

Comparable sales from July 1, 2022 to June 30, 2024Photos documenting property condition issues or defectsIndependent appraisal reportRepair estimates for needed workProperty record card showing data errors (square footage, features)

Boulder County Assessor Contact

Boulder County Assessor's Office

Phone: 303-441-3530

Address: 1325 Pearl Street, 2nd Floor, Boulder, CO 80302 (Mailing: PO Box 471, Boulder, CO 80306-0471)

Website: https://bouldercounty.gov/departments/assessor/

Online Portal: https://bouldercounty.gov/property-and-land/assessor/appeals/

Hours: Monday-Thursday 7:30 a.m. - 5:00 p.m. (Boulder office); Longmont satellite office (515 Coffman Street, Suite 114) open Mondays only

Tax Exemptions in Boulder County

Senior Homestead Exemption

50% of the first $200,000 of actual value (saves roughly $700-$1,000/year)

If you're 65+ and have owned and occupied your home for 10+ continuous years, 50% of the first $200,000 of actual value is exempt , with no income limit.

Eligibility: Age 65+ as of January 1 with 10+ years of continuous ownership and occupancy of primary residenceDeadline: July 15

Disabled Veteran Exemption

50% of the first $200,000 of actual value

50% of the first $200,000 of actual value of the veteran's primary residence is exempt from taxation, and the state reimburses the county treasurer for the lost revenue.

Eligibility: Disabled Veterans with 100% Permanent and Total rating (no age requirement) or TDIU Veterans rated 70%+ but paid at the 100% rate Deadline: July 1

Gold Star Spouse Exemption

50% of the first $200,000 of actual value

Qualified Gold Star Spouses may receive a 50% property tax exemption on the first $200,000 of their home's value, applicable only to their primary residence.

Eligibility: Surviving spouse of a service member who died in the line of duty and received a death gratuity from the Department of Defense; must not have remarriedDeadline: July 1

Senior Primary Residence Classification

Similar benefit to senior exemption (50% of first $200,000)

A property tax classification is available in 2025 and 2026 for qualifying senior citizens who received the senior exemption in 2020 or later but are no longer eligible for that program, offering similar tax relief benefits.

Eligibility: Previously qualified for senior exemption in 2020 or later; meets owner-occupier criteria for new primary residenceDeadline: July 15

Boulder County Appeal Packet — $49

Comparable sales evidence, county-specific filing guide, and professional cover letter. Enter your address to get started.

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Frequently Asked Questions

What is the deadline to appeal my property taxes in Boulder County for 2026?

Appeals of real property values can be filed with the Assessor between May 1 and June 8, while appeals of business personal property values can be filed between June 15 and June 30, and these deadlines are strictly enforced. If you miss the June 8, 2026 deadline, you generally must wait until the next valuation cycle. After receiving the Notice of Determination by August 15, you have until September 15 to file a written appeal with the County Board of Equalization.

How do I file a property tax appeal in Boulder County online?

You can file an online appeal at the Boulder County Assessor's appeals page, but you will need to create an account through Just Appraised (the county's vendor for online forms), and once you create an account you will receive a confirmation email to authorize your account. The online portal is available at bouldercounty.gov/property-and-land/assessor/appeals. You can also mail your completed appeal form to PO Box 471, Boulder, CO 80306-0471, or drop it in an Assessor's drop box.

What evidence do I need for a Boulder County property tax appeal?

Your property has been compared to similar homes that sold in the 24-month period from July 1, 2022 to June 30, 2024, so you should gather as much information as you can on similar properties in your area. The strongest evidence includes recent comparable sales within that data window, photos of any property condition issues, repair estimates, and an independent appraisal if available. The Boulder County Assessor provides Comparable Sales Lists with Time Trending to help you identify supporting sales.

What happens at a Boulder County Board of Equalization hearing?

After receiving your Notice of Determination, you can file a written appeal with the County Board of Equalization by September 15, and instructions on how to file to the County Board of Equalization will be included with your notice of determination. At the hearing, you'll present comparable sales, photos, and other evidence supporting a lower value, typically in a 5-15 minute presentation. The board members will ask questions and issue a written decision, which you can further appeal within 30 days to the Board of Assessment Appeals, arbitration, or district court.

What is the senior homestead exemption worth in Boulder County?

If you're 65+ and have owned and occupied your home for 10+ continuous years, 50% of the first $200,000 of actual value is exempt, with no income limit, but the 10-year occupancy requirement is strict. The exemption typically reduces a property tax bill by about $500, though this varies with each local mill levy. Applications must be submitted to the Boulder County Assessor by July 15.

How is my Boulder County property assessed and how often does it change?

State statute requires that each property in the county be re-valued by the County Assessor in odd numbered years. In Boulder County, assessment notices are sent in the spring each year and typically reach your mailbox by the middle of May, and each property owner receives an assessment notice that contains both the market value and assessed value, along with an estimate of your property tax bill. The 2025 reassessment applies to taxes payable in 2026 and used sales data from July 2022 through June 2024.

How much can I save by appealing my Boulder County property taxes?

In Boulder County, the median home price is $722,900, with tax bills ranging from $2,383 at the 25th percentile to $7,627 at the 90th percentile. If your home is over-assessed by 10%, you could save several hundred dollars per year at Boulder County's effective rate of approximately 0.54%. Higher-value Boulder properties in the 80304 and 80302 ZIP codes can see savings of $700-$1,500 annually from a successful appeal.

What if my Boulder County appeal is denied by the Assessor?

If you disagree with the Assessor's determination, you can file a written appeal to the Board of Equalization (BOE) on or before September 15. Whether you decide to appeal with the court or use another option, your appeal must be started no later than 30 days after the date the decision of the County Board of Equalization was mailed to you, and you may file an appeal with the Board of Assessment Appeals, which is a state government board that is part of the Colorado Department of Local Affairs. You may also pursue binding arbitration or file in district court.

Official Resources

Boulder County Assessor - Real Property Appeals →

Official page for filing real property value appeals, including online filing instructions and comparable sales lookup tools.

Boulder County Assessor's Office →

Main assessor's office page with property search, exemption applications, and contact information.

Colorado Division of Property Taxation →

State agency overseeing assessment rates, filing deadlines, and the Board of Assessment Appeals process.

Colorado Senior & Veteran Property Tax Exemption Info →

Official state information on the senior homestead and disabled veteran property tax exemptions, including eligibility and application forms.

Boulder County Property Search →

Official Boulder County Assessor's property search tool for looking up assessed values, parcel data, and property characteristics.

For state-wide appeal information including Colorado's assessment ratio and deadlines, see our Colorado Property Tax Appeal Guide →

Considering professional help with your appeal? Compare pricing, coverage, and pros/cons in our Best Property Tax Appeal Services (2026) or browse side-by-side service comparisons →

More Colorado Counties

Adams County (Brighton)Arapahoe County (Littleton)Denver County (Denver)Douglas County (Castle Rock)El Paso County (Colorado Springs)Jefferson County (Golden)

← All Colorado property tax appeal info

Sources: https://bouldercounty.gov/property-and-land/assessor/appeals/ | https://bouldercounty.gov/departments/assessor/ | https://dpt.colorado.gov/locality/boulder-county-assessor | https://www.ownwell.com/trends/colorado/boulder-county | https://dpt.colorado.gov/property-tax-exemption-for-veterans-with-a-disability-and-gold-star-spouses

Last verified: 2026-05-15