How Colorado property tax works
Colorado taxes only a small slice of a home's value. The assessor sets the actual value, then a state-set residential assessment rate turns it into assessed value, and the mill levies apply to that. Since 2025 there are two assessment rates:
- 7.05% of value for school district levies
- 6.25% of value for all other local levies (county, city, fire, library, water and so on)
So you can't just multiply one total mill levy by one assessed value. Tax = (value × 7.05% × school mills ÷ 1,000) + (value × 6.25% × other mills ÷ 1,000). For a $550,000 home that's $38,775 of school assessed value and $34,375 of local assessed value.
Local governments' property tax revenue is also capped. A 2024 law limits growth to 5.25% a year (times the years in the reassessment cycle) unless voters approve more.
2025 mill levies and what a $550,000 home pays
Total levies for a typical tax area in each city, for taxes due in 2026, split into school and other local mills. Your exact total depends on your tax area, including metro districts, which can add a lot in newer suburbs.
| City (tax area) | Total mills | School | Other local | Tax on $550,000 |
|---|---|---|---|---|
| Longmont | 97.589 | 57.717 | 39.872 | $3,609 |
| Aurora (Aurora Public Schools) | 98.232 | 73.186 | 25.046 | $3,699 |
| Arvada | 97.441 | 44.349 | 53.092 | $3,545 |
| Centennial | 96.155 | 54.108 | 42.047 | $3,543 |
| Fort Collins | 92.728 | 54.090 | 38.638 | $3,426 |
| Lakewood | 91.399 | 44.349 | 47.050 | $3,337 |
| Boulder | 89.200 | 48.044 | 41.156 | $3,278 |
| Aurora (Cherry Creek Schools) | 79.604 | 54.108 | 25.496 | $2,974 |
| Denver | 79.602 | 52.274 | 27.328 | $2,966 |
| Loveland | 79.783 | 44.836 | 34.947 | $2,940 |
| Grand Junction | 67.037 | 42.218 | 24.819 | $2,490 |
| Colorado Springs (District 11) | 51.349 | 37.695 | 13.654 | $1,931 |
Even the highest of these works out to only about 0.65% to 0.67% of market value, low by national standards. Colorado Springs is lowest because its city, county and library levies are all small; in the Academy District 20 part of north Colorado Springs the total is closer to 59 mills.
The school district drives most of the differences. Aurora residents in Aurora Public Schools pay 73.186 school mills, against 54.108 in the Cherry Creek part of the city. In Jefferson County the school levy is the same everywhere (44.349), and the gap between Lakewood and Arvada comes from the fire and park districts.
What changes for 2026
For tax year 2026 (bills paid in 2027), the local assessment rate rises to 6.8%, but the local value is first reduced by 10% of the home's value, up to $70,000. The school rate stays at 7.05%. On a $550,000 home, the local assessed value becomes ($550,000 − $55,000) × 6.8% = $33,660, slightly lower than for 2025. County officials say the 2026 rates may be finalized in November 2026.
Many homeowners saw bigger bills in 2026 because a temporary $55,000 value reduction from 2024 expired.
Senior exemption
Homeowners 65 and older who have owned and lived in their home for at least 10 years (and their surviving spouses) can exempt 50% of the first $200,000 of actual value. A temporary rule for 2025 and 2026 let seniors who moved keep part of the benefit, but a 2026 law ends it from tax year 2027, and a proposed constitutional amendment to make the exemption portable didn't make the 2026 ballot. See senior exemptions by state.
Deadlines and appeals
- Payments: pay in two halves, due the last day of February and June 15, or in full by April 30.
- Protests: protest your value to the assessor by June 8, then appeal to the county Board of Equalization by July 15. Values are reset every two years, so the odd-year notice is the one to watch. See our appeal guide.
Where these numbers come from
Mill levies are from county assessors' and treasurers' 2025 levy tables: Arapahoe County's taxing district levy report, Jefferson County's tax authority and tax area lists (city totals are our sums matched to tax areas), El Paso County's 2025 mill levies, Larimer County's 2025 mill levies by tax area, Boulder County's 2025 mill levy changes, the Mesa County Assessor and the Denver Assessor's 2025 abstract. Assessment rates and the 2026 changes are from HB24B-1001 and Boulder County's tax calculation guide. The senior exemption rules are from SB24-111, SB26-116 and HCR25-1001. Deadlines are from Larimer, Jefferson and Arapahoe county guidance. For ZIP-level data, start from our Colorado page.