How a property tax bill is built in Alamosa County

Two similar houses in Alamosa County can have different tax bills, and the reason is in how the bill is built. In Colorado, a property tax bill comes from three parts working together.

First is the actual value of the property, which the county assessor estimates. Second are the assessment rates, set by state law, which turn that value into a smaller “assessed value.” In recent years the state has used a different residential assessment rate for school district taxes than for other local government taxes, so the same home can have more than one assessed value depending on which district is taxing it. Third are the mill levies — the rates charged by each taxing district that covers the property. A single parcel can sit inside several districts at once: the county, a town, a school district, and special districts for things like fire, water, or roads. Each district’s levy is applied to the assessed value that applies to it, and the bill adds up the results.

This is why a tax bill is really a stack. Two homes worth about the same can land in different sets of districts, so they end up with different totals. The assessor handles the value side; the county treasurer collects the tax and passes it on to each district.

Rates and levies change, so it is not worth memorizing a number. To see how a specific Alamosa County parcel is taxed, start with the Colorado Division of Property Taxation’s guide, “Understanding Property Taxes in Colorado,” and the county assessor’s office.