Boulder County, CO Property Tax: $3,821/yr (2026)
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The effective property tax rate in Boulder County is 0.54% of assessed home value. On a home at the county median value of $713,900, that works out to about $3,855 per year, or $321 per month. Boulder County is located in northern Colorado, and is home to approximately 328,317 residents.
About Boulder County
Boulder County covers approximately 726.4 square miles in Colorado. The county is home to about 328,317 residents living in roughly 142,809 housing units, of which 59.1% are owner-occupied. The median household income is $102,772, and the median home was built in 1986.
Boulder County borders Broomfield County, Gilpin County, Grand County, Jefferson County, Larimer County — useful comparisons if you're considering nearby areas with potentially different tax rates.
How Property Taxes Work in Colorado
Property taxes in Colorado 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 Colorado 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 Boulder County Assessor's office to learn which exemptions apply to your property and when to file.
Boulder County vs. Neighboring Counties
| Location | Eff. Rate | Median Home | Annual Tax |
|---|---|---|---|
| Boulder County, CO | 0.54% | $713,900 | $3,855 |
| Colorado state average | 0.39% | — | $2,784* |
| Broomfield County | 0.62% | $631,600 | $3,888 |
| Gilpin County | 0.23% | $512,600 | $1,177 |
| Grand County | 0.35% | $507,200 | $1,763 |
| Jefferson County | 0.47% | $604,400 | $2,867 |
| Larimer County | 0.50% | $532,200 | $2,662 |
| US national average | 1.10% | $281,900 | $3,101 |
*State average annual tax computed at Boulder County's median home value of $713,900. Source: US Census ACS 2023 5-year estimates.
Frequently Asked Questions
How does Boulder County's property tax rate compare to the rest of Colorado?
At 0.54%, Boulder County is higher than the Colorado state average of 0.39%. On a home at the county median of $713,900, that means about $3,855 per year — versus $2,784 at the state average rate, a difference of $1,071 per year. Compared to the national average of 1.10%, Boulder County is below average.
What's a typical annual property tax bill in Boulder County?
For a home at the county median value of $713,900, the annual property tax in Boulder County is approximately $3,855 — or about $321 per month. For a home worth $1,070,850, expect around $5,783 per year. For a $1,427,800 home, approximately $7,710 per year. Use the calculator above to estimate taxes for any assessed value.
Where do I appeal a Boulder County property tax assessment?
Property assessment appeals in Boulder County are handled by the Boulder County Assessor's office. 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 Boulder County?
Colorado 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 0.54% shown here. Contact the Boulder 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