Adams County, CO Property Tax Appeal Guide for 2027

What deadline matters first

For 2027 Adams County real property, the deadline that matters first is the Assessor protest window: May 1 through June 8, 2027. Adams County says real property appeals for value or classification are held during that period, and appeals after June 8 cannot be accepted unless the legal weekend or holiday rule applies. Adams County Assessor Appeals Process

If the Assessor denies your protest or only partly changes the value, the next deadline is usually September 15, 2027 to petition the Adams County Board of Equalization. Email BOE petitions must be received by 11:59 p.m. on September 15, mailed petitions must be postmarked by September 15, and hand-delivered petitions must be received by September 15. Adams County BOE Filing an Appeal

Adams County states that it reviews appeals for the valuation of the property only, not the amount of taxes you pay, and that mill levies vary by tax area. The countywide effective tax rate estimate in this analysis is about 0.60%, but your tax bill depends on your assessment rate and the overlapping mill levies for your specific tax area. Adams County Assessor Appeals Process

For one 2023 appeal count and success context, Axios Denver reported that Adams County received 18,303 assessment appeals and had denied 77% of those reviewed halfway through the review period. That older news sample is not a prediction for 2027, but it shows why good evidence matters. Axios Denver

The common value appeal

The common homeowner filing reason is Real property value / valuation. Use this when you believe Adams County’s actual value is higher than the market value of your home as of the correct Colorado appraisal date.

For the 2027 reappraisal, the target date is June 30, 2026. Colorado’s level-of-value rule uses the one-and-one-half-year period immediately before July 1 preceding the assessment date, with older six-month periods used only when the first period does not provide adequate comparable data. C.R.S. 39-1-104

For a typical 2027 residential value protest, focus on comparable sales from January 1, 2025 through June 30, 2026, adjusted or explained to the June 30, 2026 level of value. The best sales are usually similar homes in similar locations, with differences explained in ordinary terms such as size, condition, quality, basement finish, garage, lot, and date of sale.

Other reasons you might appeal

Property classification means the county placed your property in the wrong class or subclass. For a homeowner, this could matter if the property’s use or assigned class does not match the facts. Classification rules can affect how value is treated, so do not treat this as a simple dollar dispute.

Property characteristics / assessment record correction means the county’s records contain a factual mistake. Examples include incorrect finished square feet, basement finish, room count, condition, land characteristics, use, or another assessment data item that affects value or classification.

Rent-producing commercial property documentation applies to rent-producing commercial real property. Adams County lists required income, tenant reimbursement, expense, and rent-roll information for these appeals under C.R.S. § 39-5-122(2.5). This is mainly for commercial owners, not a standard owner-occupied home protest. Adams County Assessor Appeals Process

If your Notice of Assessment says something else changed

A Notice of Assessment is the assessment notice that tells you what the county believes about your property, such as value, classification, or key property facts. In Adams County, the official notice names to watch are Notice of Value (NOV) and, after an Assessor protest, Notice of Determination. Adams County Assessor Appeals Process

The Notice of Value is the first document to review when the May protest period opens. Compare it with your home, not just with last year’s tax bill. Look for value, classification, land and building details, and anything that appears different from the actual property.

The Notice of Determination is the Assessor’s response after your protest. If you disagree with that decision, Adams County says you may continue to the Board of Equalization by September 15. Save the signed Notice of Determination because Adams County requires it with the BOE petition. Adams County BOE Filing an Appeal

What evidence helps

For Real property value / valuation, the strongest starting point is a small set of qualified, confirmed, typical arm’s-length comparable sales. In plain English, an arm’s-length sale usually means unrelated buyers and sellers each acted in their own interest, not a family transfer or unusual deal.

Colorado assessment guidance says assessors confirm and verify qualified sales, screen out non-arm’s-length transactions, and adjust sales where needed for items such as personal property or atypical financing. It also recognizes that verified sales should reflect the property characteristics and sale terms at the time of sale. Colorado Assessors' Library

Use the most similar nearby sales available. No Adams County-published fixed comparable-sale radius, gross-living-area variance, lot-size variance, or maximum number of homeowner-submitted comparable sales was found in the verified policy snapshot. A short, clear set of the best sales is usually easier to understand than a long list of weaker sales.

Also include photos, repair estimates, inspection notes, appraisal information, MLS or closing data if available, and documentation of county record errors. If you believe the county record is wrong, show both the county’s listed fact and the corrected fact.

What the board can and cannot decide

In Adams County, the Board of County Commissioners sits as the Board of Equalization (BOE). The county describes the BOE’s mission as assuring just and equalized property tax assessments, and states that the BOE is not affiliated with the Assessor’s Office. Adams County Board of Equalization

The BOE can consider your petition after you disagree with the Assessor’s Notice of Determination. You must resubmit evidence you already gave the Assessor if you want the BOE to consider it. Adams County also says documentary evidence must be provided by 4:30 p.m. at least two business days before the hearing. Adams County BOE Rules and Procedures

The BOE cannot lower your tax bill simply because the bill feels unaffordable. Adams County’s Assessor page says the county reviews valuation, not the amount of taxes or mill levies. Also, the county warns that a BOE hearing can result in the protested value being increased if the evidence supports an increase. Adams County Board of Equalization

If you are dissatisfied with the County Board of Equalization decision, Adams County lists further options: Board of Assessment Appeals, District Court, or Binding Arbitration. The key date is not later than 30 days after the CBOE decision. Adams County Assessor Appeals Process

How TaxSauce helps

TaxSauce helps turn a stressful assessment notice into a clear preparation checklist. We help you identify the official appeal reason, organize your facts, compare your home with relevant sales, and prepare a packet you can review before filing.

For Adams County, that means paying close attention to the May 1 through June 8 Assessor protest window, the June 30, 2026 target date, and the January 1, 2025 through June 30, 2026 primary comparable-sale window for 2027.

You remain in control. You decide what evidence is accurate, whether to proceed, and how to submit the protest or BOE petition. TaxSauce can estimate, organize, prepare, and help, but it does not promise a reduction or guarantee that the county will accept every argument.