How a Costilla County property tax bill is actually built

A property tax bill is not one number someone picks. In Colorado, including Costilla County, it is built from three parts, and knowing them helps you read your bill and compare properties.

First is the actual value, the county assessor’s estimate of what the property is worth. Second is the assessment rate, set by state rules, which turns that value into a smaller taxable value. Third is the mill levy, the rate set by the local taxing entities that serve the property, such as the county, a school district, and any special districts.

Here is why two similar-looking properties can owe different amounts: they may sit in different combinations of taxing districts, so their mill levies differ. Rural land and land inside a town, for example, are often served by different sets of districts.

Because these rates change year to year, it is not worth memorizing a number. What helps is knowing who to ask. The county assessor handles your value, the county treasurer handles billing and payment, and the state ties the pieces together.

To check how your Costilla County bill is figured, start with the county assessor and treasurer, and use the state Division of Property Taxation for how the system works.