Taxes in Castle Rock
Castle Rock's tax picture combines Colorado's statewide flat income tax with a real, sourced, structurally simpler sales tax than either Highlands Ranch's or Parker's -- a direct, disclosed consequence of the Town's 2005 decision to opt out of RTD.
Exploring the idea of moving?
We can connect you with a local real estate professional who knows the area -- no pressure, just a starting point.
Learn moreColorado's flat, TABOR-variable state income tax
Colorado's flat income tax rate is 4.40% for 2026 -- not fully fixed, since a TABOR-driven refund mechanism can temporarily lower it further in years the state certifies a qualifying revenue surplus. See colorado.js for the full mechanism.
Sales tax: 8.1% combined, with no RTD/SCFD layer
Castle Rock's own official FAQ confirms a combined 8.1% sales tax rate: 2.90% State of Colorado + 1.00% Douglas County + 4.20% Town of Castle Rock (the Town's own rate rose from 4.00% to 4.20% effective January 1, 2025). Because Castle Rock voters opted the town OUT of RTD in 2005, this combined rate carries NO 1.0% RTD or 0.1% SCFD special-district layer -- a real, structural difference from both unincorporated Highlands Ranch's 5.0% rate and incorporated Parker's 8.0% rate, both of which include those special-district components.
Property tax: a research gap disclosed rather than guessed
A precise, current, Castle-Rock-specific effective property tax rate (combining Douglas County's, the Town's, and DCSD's own separate mill levies) was not resolved to one verified figure this research pass -- Colorado's own statewide average effective rate (~0.50%) and Douglas County's own average (~0.55%, per colorado.js and highlands-ranch-co.js) are the closest available reference points, but neither is Castle-Rock-specific. Confirm the exact combined rate for a specific address directly with the Douglas County Assessor.
Key takeaways
- Colorado's flat state income tax is 4.40% for 2026 (TABOR-variable).
- Castle Rock's combined sales tax rate is 8.1% (2.90% state + 1.00% county + 4.20% Town, raised from 4.00% effective Jan. 1, 2025) -- with NO RTD/SCFD special-district layer, thanks to the Town's 2005 RTD opt-out.
- A precise, Castle-Rock-specific combined effective property tax rate was not resolved to one verified figure this research pass -- confirm directly with the Douglas County Assessor for a specific address.
Want to know what your budget actually buys here?
Tell us a bit about what you're looking for and we'll connect you with someone local who can walk you through real numbers.
Get local guidanceRead the full Castle Rock overview for the complete picture -- housing, taxes, climate, and who this place genuinely fits.
Planning a move?
Tell us what you're looking for and we'll connect you with a local expert who can help you make it happen.
Talk to a local expert