Assessment ratios (share of actual value that is taxed)
Commercial-classed improved property (offices, retail, lodging, warehouse): 27% (2025) → 25% (2026); 2024 was 27.9% (26.4% for renewable energy), with a temporary $30,000 actual-value reduction on commercial-classed property that did not apply to industrial. Industrial-classed improved property (manufacturing, processing, refining), vacant land, and business personal property: 26% (2026), meaning equipment now assesses a point above commercial-classed buildings and at parity with industrial-classed plants. Residential: 6.8% for local-government levies (after statutory relief of 10% of the first $700,000 of value) and 7.05% for school levies, which get no such relief (2026). From 2027: 25% for all nonresidential real property and all business personal property under current law, so industrial-classed property, vacant land and equipment drop a point to match commercial-classed buildings (C.R.S. § 39-1-104(1.9)(c), enacted by HB24B-1001; see the 2027 reappraisal). Ratios are statewide, set per tax year, which makes the ratio itself a classification check: assessed ÷ actual on your notice tells you what the county thinks your property is. The bill follows one formula: tax = actual value × assessment ratio × mill levy; at a representative 90-mill levy, a 2026 commercial building pays an effective ~2.25% of actual value.
The calendar
Colorado revalues every two years. For the 2027 reassessment: values are set as of the June 30, 2026 level-of-value data date; notices of valuation mail May 1, 2027; real-property protests are due June 1, 2027 (SB26-046, effective with the 2027 cycle). Business personal property runs its own lane every year: declarations April 15, notices June 15, protests June 30 (July 15 and July 31 from 2027 in counties using the alternate protest procedure, the nine over 300,000 in a reappraisal year), exemption $56,000 per county through 2026 and a flat $58,000 from 2027 (SB26-116). Abatements reach back two years; tax year 2024 closes permanently January 1, 2027. Full table: appeal deadlines.