Arapahoe County does not have one property tax rate. What you owe is built from two moving parts: a state-set assessment rate that converts your home’s market value into a smaller “assessed value,” and a stack of local mill levies set each year by every taxing district your parcel sits in. For 2026, residential property uses a 6.8% assessment rate for local government levies and a 7.05% rate for school district levies, and those two assessed values are then multiplied against the specific mill levies for your address.
How Your Rate Is Actually Built
Colorado law requires the county assessor to determine the actual market value of every taxable property. That market value is reduced by a state-mandated assessment rate to produce an assessed value, and the mill levies for your location are applied to that smaller number. Residential property carries much lower assessment rates than commercial or industrial property, which is why a $500,000 house and a $500,000 shop can produce very different bills.
One mill equals one dollar of tax for every $1,000 of assessed value. Every taxing district that serves your property sets its own mill levy each year based on its budget. A typical parcel is served by seven or more entities: the county, a city or town, a school district, a fire protection district, a water and sanitation district, a library district, and often one or more metropolitan districts or urban renewal authorities. Those individual mill levies stack to produce the total that applies to your address. Two homes with identical market values on opposite sides of the county can owe different amounts because they fall under different service districts.
Mill levies also shift from year to year. Voter-approved bonds for school construction or infrastructure push the total up, sometimes for 20 years or more. When a bond is fully repaid, those mills drop off.
2026 Assessment Rates
Starting in 2025, Colorado split residential property into two assessment rates rather than one. For the 2026 tax year:
- Residential rate for local government levies: 6.8%, with 10% of the first $700,000 of actual value subtracted before the rate is applied, and a minimum assessed value of $1,000.1Colorado Department of Local Affairs Division of Property Taxation. Residential Local Government Assessment Rate
- Residential rate for school district levies: 7.05%, with its own separate reduction applied to the first $200,000 of value.2Justia. Colorado Code 39-1-104.2 – Residential Assessment Rate
Non-residential property uses a single rate for all levies: 25% for commercial improved and agricultural; 26% for commercial other, industrial, vacant land, and state assessed. These rates are set by state law and apply the same in every Colorado county.3Colorado Department of Local Affairs Division of Property Taxation. Understanding Property Taxes in Colorado
Running the Numbers on a $500,000 Home
The basic formula is assessed value multiplied by mill levy. For residential property, you run it twice, once for local levies and once for school levies, then add them together.
Take a home with a $500,000 market value. Applying the 6.8% local rate after the 10% value reduction produces a local assessed value of roughly $30,600. Applying the 7.05% school rate after its own reduction produces a school assessed value of roughly $28,200. If the combined local mill levies at that address total 50 mills and the school levy is 40 mills, you’d owe about $1,530 from local levies plus $1,128 from school levies, or roughly $2,658 for the year.
Mill levies vary widely by location, so treat any manual estimate as a rough guide. The Treasurer’s annual tax statement shows the precise breakdown.
Finding the Mill Levies for Your Address
The Arapahoe County Assessor’s online property search lets you look up any address or parcel and see every taxing authority that applies to it, along with each entity’s current mill levy.4Arapahoe County. Property Search The Assessor also publishes annual abstracts of mill levies and tax district information.5Arapahoe County. Mill Levies and Tax Districts This is the only reliable way to see exactly which districts bill your parcel and why your neighbor in a different subdivision might pay a noticeably different total.
Protesting Your Valuation to Lower the Bill
The biggest lever you have is the market value the assessor assigned. If that number is too high, every downstream calculation is inflated. Filing a protest costs nothing.
After the assessor mails notices of valuation (typically in early May), you have until June 8 to submit a written protest for real property.6FindLaw. Colorado Code 39-5-122 – Taxpayer’s Right to Protest Valuation You can hand-deliver, mail (postmark counts), or use any form provided with the valuation notice. The protest must state in general terms why the value is wrong. Valid grounds include being valued too high compared to recent comparable sales, being assessed twice, being erroneously assessed to you, or being exempt from taxation.
Your strongest evidence is recent comparable sales in your neighborhood, ideally similar homes sold in the prior 12 to 18 months. Errors in the assessor’s records about square footage, lot size, or condition are also solid grounds. The assessor must conclude all real property protest hearings by June 1.7Colorado Department of Local Affairs Division of Property Taxation. Filing Deadlines
If you’re still unsatisfied, you can appeal to the Arapahoe County Board of Equalization. That appeal must be postmarked or filed in person by July 20, and the Board must render all decisions by August 5.8Colorado Department of Local Affairs Division of Property Taxation. Protests and Appeals Further appeals to the State Board of Assessment Appeals or district court are available after that.
Exemptions That Shrink the Taxable Value
Colorado offers several programs that reduce how much of your home’s value the rate applies to. None are automatic; you have to apply.
Senior Citizen Exemption
If you are at least 65 as of January 1 and have owned and occupied your home as a primary residence for at least 10 consecutive years, you qualify for a 50% exemption on the first $200,000 of actual value.9Colorado Department of Local Affairs Division of Property Taxation. Senior Citizen and Veterans With a Disability Property Tax Exemption The state reimburses local districts for the exempted amount. Applications are due between January 1 and July 15.10Colorado Division of Veterans Affairs. Property Tax Exemption
Disabled Veteran and Gold Star Spouse Exemption
Veterans with a 100% permanent service-connected disability rating from the VA, or those receiving individual unemployability compensation, qualify for the same 50% exemption on the first $200,000 of actual value, with no age requirement. The veteran must have received an honorable discharge and must own and occupy the home as of January 1. Surviving spouses of service members who died in the line of duty or from a service-related condition also qualify if they have not remarried. The application window runs January 1 through July 1.10Colorado Division of Veterans Affairs. Property Tax Exemption
Property Tax Deferral
Homeowners who are at least 65, or on active military duty, can defer their property taxes through a state loan that places a junior lien on the home. Interest accrues from May 1 of the year the deferral is claimed, and the balance comes due when you sell, rent out the property, transfer title, or take a reverse mortgage. You must reapply each year between January 1 and April 1.11Colorado State Treasury. Property Tax Deferral Program Overview As of 2026, county treasurers handle applications rather than the state, and the separate “tax growth deferral” category has been eliminated for new applicants.
When the Bill Is Due
You have two payment options. Pay the full amount by April 30, or split it into two equal installments with the first half due by the last day of February and the second half due by June 15.12Justia. Colorado Code 39-10-104.5 – Payment Dates – Optional Payment Dates – Failure to Pay – Delinquency – Repeal Bills under $25 must be paid in full by April 30. Mailed payments are credited as of the postmark date.
The Treasurer accepts electronic checks and credit cards through the online portal (credit cards carry a higher convenience fee), mailed checks, secure drop-box payments, and in-person payments.13Arapahoe County. Pay Taxes Online payments are accepted through September 30, though interest applies after the statutory deadlines. If the Treasurer mails the statement late, no interest accrues on the first installment if you pay within 30 days of the mailing.
If You Don’t Pay
Missing a deadline triggers 1% interest per month on the unpaid balance, calculated from the first day of the month following the deadline, and both installments accrue separately if both go unpaid.12Justia. Colorado Code 39-10-104.5 – Payment Dates – Optional Payment Dates – Failure to Pay – Delinquency – Repeal Unpaid taxes eventually go to the annual tax lien sale, where the county’s lien transfers to a purchaser and any later payment is treated as a lien redemption with additional interest owed to the lienholder.14Arapahoe County. Tax Lien Sale For real property, a lienholder can apply for a Treasurer’s Deed after three years. Paying before the lien sale, or redeeming promptly after, is far cheaper than letting it progress.