Boulder County Property Tax Appeal, Colorado

Travis Bunn·Updated July 24, 2026

Boulder County is located in north-central Colorado along the Front Range, with the city of Boulder serving as the county seat. The county has an estimated population of approximately 328,000 and includes major cities such as Longmont, Louisville, Lafayette, Superior, and Erie. With a median home value of $713,900 and an effective property tax rate of 0.54%, Boulder County homeowners pay a median annual property tax of $3,821, which is significantly higher than the national median of $2,400 despite having a lower effective rate than the national median of 0.91%. Property tax appeals are particularly important in Boulder County because even modest over-assessments can result in hundreds of dollars in excess taxes annually given the high property values.

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

Median Home

$713,900

Tax Rate

0.54%

Annual Tax

$3,821

Population

328,317

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

This year's appeal window has passed in most of Colorado. Order now and we re-run your numbers free when the window reopens, so your evidence is ready the day your next notice lands.

The appeal window for real property valuations in Boulder County is May 1 through June 8, 2026. Appeals must be postmarked or filed by June 8, 2026. Deadlines are strictly enforced, and missing the deadline means waiting until the next valuation cycle.

See if your Boulder County home is over-assessed

Free analysis in 30 seconds. If the numbers support a appeal, your complete evidence packet is $49.

✓ All 50 states✓ Instant results✓ $49 flat fee

Colorado homes beneath snow-covered mountains. Boulder County appeal guide.

How Boulder County Assesses Property

6.25%of market value

Assessed by: Boulder County Assessor's Office

Assessment cycle: biennial

Notices typically mailed: May (typically mailed May 1)

Boulder County assesses properties biennially in odd-numbered years, with values based on sales data from a 24-month period ending June 30 of the prior even-numbered year. The assessed value is calculated by multiplying your property's market value by Colorado's residential assessment ratio of 6.25%. For example, if your home's market value is $713,900 (Boulder County's median), at Colorado's 6.25% assessment ratio your assessed value would be $44,619, resulting in approximately $3,853 in annual taxes at the county's effective rate of 0.54%.

The Appeal Process

Appeals are heard by the County Board of Equalization. The County Board of Equalization conducts hearings where you present your evidence, including comparable sales and documentation of property conditions. The board reviews your appeal and the Assessor's determination before issuing a decision.

Review your Notice of Valuation mailed around May 1, which shows your property's actual value, assessed value, and property characteristics. Verify all property information is accurate and compare your assessed value to similar properties.

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, Boulder, CO 80306, or in person at 1325 Pearl Street. Include comparable sales data, photos, and documentation of any property condition issues.

Receive the Notice of Determination (NOD) from the Assessor's Office by August 15, 2026, which will contain the results of your appeal and the revised assessed value (if any adjustment was made).

If you disagree with the Assessor's determination, file a written appeal with the County Board of Equalization (CBOE) on or before September 15, 2026. Present your evidence at the CBOE hearing, including comparable sales, photographs, and documentation supporting a lower value.

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

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

Filing Methods

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

mail:Boulder County Assessor, P.O. Box 471, Boulder, CO 80306-0471

in-person:Boulder County Assessor's Office, 1325 Pearl Street, Boulder, CO 80302 (Monday-Thursday, 7:30 AM - 5:00 PM)

Evidence to Bring

Comparable sales of similar properties in your area that sold during the assessment period (July 1, 2022 - June 30, 2024)Photographs documenting property condition, defects, or needed repairsIndependent appraisal or professional valuation reportRepair estimates or documentation of property damageProperty inspection reports or engineering assessments

Boulder County Assessor Contact

Boulder County Assessor's Office

Phone: 303-441-3530

Address: 1325 Pearl Street, Second Floor, Boulder County Courthouse, Boulder, CO 80302

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

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

Hours: Monday-Thursday, 7:30 AM - 5:00 PM

Tax Exemptions in Boulder County

Senior Homestead Property Tax Exemption

50% of the first $200,000 of actual value (maximum exemption of $100,000 in actual value)

Available to qualifying senior citizens age 65+ who have owned and occupied their primary residence for at least 10 consecutive years as of January 1.

Eligibility: Must be 65 years or older by January 1 of the application year, owned and occupied the home as primary residence for at least 10 consecutive years, no income limit appliesDeadline: July 15 (late applications accepted July 16 - August 15)

Disabled Veteran Property Tax Exemption

50% of the first $200,000 of actual value (maximum exemption of $100,000 in actual value)

Available to veterans with 100% permanent service-connected disability or individual unemployability status, as well as surviving spouses of qualifying veterans and Gold Star Veterans.

Eligibility: Veteran with 100% permanent service-connected disability rating from VA, or surviving spouse of qualifying veteran who previously received exemption; must have owned and occupied property as primary residence since January 1Deadline: July 1

Senior Primary Residence Classification

Similar tax relief benefits as the senior exemption program

Available in 2025 and 2026 for qualifying senior citizens who received the senior exemption in 2020 or later but are no longer eligible (e.g., moved to a new primary residence).

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.

✓ All 50 states✓ Instant results✓ $49 flat fee

Frequently Asked Questions

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

The deadline to appeal your property taxes in Boulder County is June 8, 2026. The appeal window opens May 1, 2026, and closes at 11:59 PM on June 8, 2026. These deadlines are strictly enforced by state law, and if you miss the June 8 deadline, you must wait until the next valuation cycle to appeal. Property owners typically receive their Notice of Valuation around May 1, giving you approximately five weeks to prepare and file your appeal with supporting evidence.

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

You can file your Boulder County property tax appeal online through the Just Appraised portal accessible at https://bouldercounty.gov/property-and-land/assessor/appeals/. You will need to create an account through Just Appraised, which is the county's vendor for online appeal forms. After creating your account, you will receive a confirmation email to authorize your account before you can submit your appeal. The online system provides tools to research comparable sales and attach supporting documentation to your appeal, making it convenient to submit all required evidence electronically.

What is the senior homestead exemption worth in Boulder County?

The senior homestead exemption in Boulder County exempts 50% of the first $200,000 of your home's actual value, providing a maximum exemption of $100,000 in actual value. This typically reduces a property tax bill by $500 to $700 annually, though the exact amount varies based on your local mill levy. To qualify, you must be 65 years or older by January 1, have owned and occupied your home as your primary residence for at least 10 consecutive years, and there is no income limit. Applications must be submitted to the Boulder County Assessor by July 15, with late applications accepted through August 15.

What happens at a Board of Equalization hearing in Boulder County?

If you disagree with the Assessor's Notice of Determination (mailed by August 15), you can file an appeal with the County Board of Equalization by September 15, 2026. At the hearing, you will present your evidence supporting a lower property value, including comparable sales from the July 2022 through June 2024 assessment period, photographs of your property, and any documentation of defects or needed repairs. The Board reviews both your evidence and the Assessor's determination before issuing a decision. The hearing provides a formal opportunity to make your case directly to an independent board, and you should come prepared with organized documentation and a clear argument for why your assessed value should be reduced.

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

In Boulder County, where the median home value is $713,900 and the effective tax rate is 0.54%, even a modest reduction in your assessed value can result in significant savings. For example, if your home is over-assessed by just 10%, you could be overpaying approximately $385 per year in property taxes. Over a typical two-year assessment cycle, that amounts to $770 in excess taxes. The actual savings depend on the percentage of overassessment and your property's value, but given Boulder County's high property values, successful appeals often save homeowners several hundred dollars annually.

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

The strongest evidence for a Boulder County property tax appeal includes comparable sales of similar properties that sold between July 1, 2022, and June 30, 2024 (the assessment period for 2026 taxes). You should gather at least three to five comparable properties with similar square footage, age, condition, and location. Additionally, provide photographs documenting your property's condition, any defects, needed repairs, or factors that negatively affect value. Other useful evidence includes independent appraisals, contractor repair estimates, property inspection reports, or documentation of issues like flood damage, outdated systems, or deferred maintenance that the Assessor may not have considered.

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

Colorado state statute requires Boulder County to revalue all properties in odd-numbered years (2025, 2027, etc.), making it a biennial assessment cycle. For the 2026 tax year, your property was assessed based on its condition on January 1, 2026, but valued as if it had sold on June 30, 2024, using comparable sales from July 1, 2022, through June 30, 2024. If your property's condition and classification remained the same since January 1, 2025, your value will typically remain unchanged from the 2025 tax year. Assessment notices are mailed in the spring (typically May 1) and include both your market value and assessed value, which is calculated at 6.25% of the market value for residential properties.

Can I appeal my Boulder County property taxes if I recently purchased my home?

Yes, you can appeal your property tax assessment in Boulder County even if you recently purchased your home, and your recent purchase price can serve as strong evidence if you bought the property during the assessment period (July 1, 2022 - June 30, 2024). If your purchase price was significantly lower than the assessed value and the sale was an arm's-length transaction, this is compelling evidence that the Assessor's valuation is too high. However, if you purchased the home after June 30, 2024, your purchase price may not be as persuasive since the assessment is based on the June 30, 2024, level of value. You must still file your appeal between May 1 and June 8, 2026, regardless of when you purchased.

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 Homepage →

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.

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 (Aurora)Denver County (Denver)Douglas County (Castle Rock)Eagle County (Eagle)El Paso County (Colorado Springs)

← All Colorado property tax appeal info

Sources: https://bouldercounty.gov/property-and-land/assessor/appeals/ | https://bouldercounty.gov/departments/assessor/ | https://bouldercounty.gov/property-and-land/assessor/senior-exemption/ | https://bouldercounty.gov/government/about-boulder-county/ | https://propertytaxrates.org/counties/colorado/boulder-county/ | https://dpt.colorado.gov/property-tax-exemption-for-senior-citizens-and-veterans-with-a-disability

Last verified: 2026-07-24