Rate Breakdown

Property taxes in Costilla County are calculated by multiplying the assessed value (minus exemptions) by the total local millage rate.

How Property Tax Works in Costilla County

In Costilla County, property taxes are calculated by applying the county’s millage rates to the assessed value of each parcel of land or improvement. The assessment is performed by the County Assessor’s Office and reflects the market value of the property as of the assessment date, which is typically January 1 of the tax year. The assessed value is then multiplied by the combined millage rate (expressed in mills, where one mill equals one‑tenth of one percent, or $1 per $1,000 of assessed value) set by the County Board of Commissioners, schools, fire protection districts, and any other special districts that levy taxes within the county.

For example, if a home is assessed at $150,000 and the total millage rate for the 2024 tax year is 23.5 mills, the tax bill would be calculated as follows:

• Assessed value: $150,000
• Millage rate: 23.5 mills = 0.0235
• Tax due: $150,000 × 0.0235 = $3,525

Costilla County publishes its annual millage rates on the Assessor’s website. Rates can change each year based on budget needs, voter-approved levies, and state‑mandated adjustments.

Available Exemptions

Colorado law provides several exemptions that can lower the taxable portion of a property’s assessed value. Costilla County applies these state‑wide exemptions, which include:

• Homestead Exemption: Reduces the taxable value of a primary residence by a flat $150,000 (or $100,000 for properties valued under $500,000). The exemption is automatic once the property is identified as a homestead.
• Senior Citizen Exemption: Residents age 65 or older may receive an additional exemption of $50,000 on their primary residence, provided they meet income criteria (generally $30,000 or less in total household income).
• Disability Exemption: Qualified disabled individuals (or households) can claim a $50,000 exemption on their primary residence. Documentation from a licensed medical professional and Colorado’s Department of Revenue is required.
• Veteran Exemption: Disabled veterans (and their surviving spouses) may obtain a $50,000 exemption per qualifying disability rating, up to a maximum of $200,000 for multiple disabilities. The exemption is applied after the homestead exemption.

To claim any exemption, submit the appropriate Colorado Department of Revenue forms (e.g., DR 250 for homestead, DR 189 for senior/disabled/veteran) to the Costilla County Assessor’s Office by the February 15 deadline.

Payment Schedule & Deadlines

Costilla County property taxes are due in two installments:

• First installment: Due November 1 (or the first business day after the first of the month) and payable until December 31.
• Second installment: Due February 1 and payable until March 31.

Payments can be made online through the county’s e‑Tax portal, by mail, or in person at the Treasurer’s Office. Property owners who wish to avoid interest charges may also set up automatic withdrawals.

Late payments incur a penalty of 5% of the unpaid amount plus interest at the state‑set rate (currently 0.5% per month). If a payment is not received by the March 31 deadline, the account may be placed in tax lien status, potentially leading to a tax sale.

Appealing Your Assessment

If you believe your property has been over‑assessed, you have the right to appeal to the Costilla County Board of Assessment Appeals (BOAA). The appeal process consists of three steps:

• Step 1 – Informal Review: Contact the Assessor’s Office within 30 days of receiving your assessment notice. Provide evidence such as recent sales of comparable properties, an independent appraisal, or documented errors.
• Step 2 – Formal Appeal: If the informal review does not resolve the issue, file a written appeal with the BOAA using Colorado Form 714, “Appeal of Property Tax Assessment.” The deadline is 30 days after the informal review decision (generally within 60 days of the assessment notice).
• Step 3 – Hearing: The BOAA will schedule a hearing, where you may present testimony, photographs, and expert reports. After consideration, the board issues a written decision. If you disagree with the decision, further appeal can be made to the Colorado Tax Appeal Board.

All supporting documentation should be organized and submitted promptly to ensure a thorough review. For assistance, the Costilla County Assessor’s Office offers a list of recommended appraisers and a FAQ guide on the appeal process.