Denver county tax assessor: how assessment, appeals, and exemptions work

Last updated 2026-07-09

What does the Denver County Assessor actually do?

The Denver County Assessor estimates the market value of every parcel in the consolidated city and county of Denver. That value is the base of your tax bill. The assessor does not set the tax rate and does not collect a dime. Denver City Council sets the mill levies. The Denver Treasurer mails the bills and takes the payments ^[1].

Every two years, on a schedule the state controls, the assessor rebuilds every residential value using sales from an 18-month look-back window. The office also keeps ownership records, processes exemption applications, and runs a public property search you can use in about 90 seconds.

Denver's assessor as of this writing is Keith Erffmeyer. The office is at 201 W. Colfax Ave., Department 406, Denver, CO 80202. Call 720-913-4162 or use the portal at denvergov.org/assessor ^[1]. Got a question about your bill amount instead of your value? That's the Treasurer, not the Assessor.

How does Denver assess residential property value?

Colorado runs a two-step process. First the assessor estimates your property's actual value, which is basically market value. Then the state applies a fixed assessment rate to get your assessed value, and the mill levy is multiplied against that assessed number.

For the 2023-2024 assessment cycle, the General Assembly set the residential rate at 6.765% for single-family homes and 6.8% for multi-family under Senate Bill 23B-001, passed as temporary relief ^[2]. Prior cycles used 6.95%. The rate moves through legislation, so confirm the current number with the Colorado Division of Property Taxation or the assessor before you run the math.

The assessor uses mass appraisal, not an individual walk-through of your house. The office sorts similar properties by neighborhood, age, condition, and physical features, then runs statistical models against recorded sales to price the whole group. Two things follow from that. Your neighbor's high sale can pull your value up. And a clerical error in your record (wrong square footage, wrong bedroom count, wrong lot size) can inflate your assessment for years with nobody catching it.

The look-back window for the 2023 cycle ran January 1, 2021 through June 30, 2022, right when Denver prices were near their peak. That timing is why so many 2023 notices landed with a thud ^[1][2].

Residential property is assessed apart from commercial, industrial, and vacant land, which carry a much higher rate (currently 27.9% for most commercial). The gap is large. A $600,000 home carries a taxable value near $40,600 at 6.765%. A $600,000 commercial building carries roughly $167,400 at 27.9%.

What is the Denver property tax appeal deadline for 2025?

The Denver protest deadline is June 8 of the reappraisal year. Notices of Valuation go out by May 1, and you get either until June 8 or 30 days after the assessor mails your notice, whichever is later ^[3]. Odd years (2023, 2025, 2027) start a fresh cycle and every owner gets a new NOV. Even years only bring a notice if your value changed for a reason outside the biennial reappraisal, like fire damage, a new addition, or a correction.

For 2025, expect your NOV by May 1, 2025. The protest deadline is June 8, 2025. Miss it and you forfeit the right to challenge your 2025 and 2026 tax bills off that assessment. There is no extension for being busy.

Here is the full Colorado timeline, using 2025 as the example:

Step	Date	Notes
Notices of Valuation mailed	By May 1, 2025	Assessor mails to address of record
Protest deadline	June 8, 2025	30-day window from May 1 mailing
Assessor decision deadline	Aug 15, 2025	Must mail written decision
Appeal to CBOE	30 days after assessor decision	County Board of Equalization
CBOE hearing	By Nov 1, 2025	Board rules by Nov 1
Further appeal options	After CBOE denial	BAA, District Court, or binding arbitration

Source: Colorado Revised Statutes §39-5-122 and §39-8-106 ^[3][4].

Bought mid-cycle and think the value is wrong? You can protest during the next open window, or file an abatement petition within two years of the tax year under C.R.S. §39-10-114 ^[4].

How do you file a protest with the Denver County Assessor?

Denver takes protests three ways: online, by mail, and in person. Online is fastest and leaves the cleanest paper trail.

Online: Go to denvergov.org/assessor and open the protest tool. You need your schedule number (it's on your NOV) and either the last four of your SSN or your property PIN. Upload your supporting documents on day one, not after you submit the bare form ^[1].

By mail or in person: Send a written protest to the Assessor's Office at 201 W. Colfax Ave., Department 406, Denver, CO 80202. If you mail it, use certified mail with return receipt so you can prove you filed on time.

Include your schedule number, your opinion of value as a specific dollar amount, and your evidence. The evidence carries the case, not the form. A reviewer is holding your packet against what their system shows. Give them something to work with.

Strong evidence includes:

• Recent sales of comparable homes ("comps") that sold within 6 to 12 months in your neighborhood, as close as you can get in size, age, and condition. Pull them from Zillow, Redfin, or the county's own sales search, and screenshot the source.
• Your own recent appraisal, if you refinanced or bought lately.
• Photos of condition problems the model can't see: a failing foundation, unpermitted space that's really substandard, a busy road that eats value.
• A correction if your property record has a factual error. Compare the assessor's square footage, bedroom count, and basement finish to your actual home. Errors show up more than people expect.

Once you file, the assessor has until August 15 to mail a written decision ^[3]. If they cut your value, done. If they don't, you get 30 days from that decision to appeal to the Denver County Board of Equalization (CBOE).

What happens at the County Board of Equalization hearing?

The Denver CBOE is a three-member panel that hears protests after the assessor has already ruled. It's looser than a courtroom, tighter than the first assessor review. You get a scheduled slot, usually 15 to 30 minutes, and you present your evidence to the panel yourself.

Bring printed copies of everything: your comps, your photos, any appraisal, and a one-page summary that opens with your conclusion ("The market value should be X, not Y, for these reasons"). The board sees dozens of cases a day. People who lead with the number and back it with organized evidence do better than people who tell a long story.

The CBOE must rule by November 1 of the protest year ^[4]. If it denies you, three doors are open: the Colorado Board of Assessment Appeals (BAA), District Court, or binding arbitration. The BAA is free and you can do it without a lawyer, though it runs slower. Arbitration needs both sides to agree and carries a filing fee. District Court is the most formal and expensive route.

For most homeowners fighting a residential number, the BAA is the sensible next step after a CBOE denial. The BAA hears hundreds of cases a year and publishes its decisions, so you can read what evidence actually moves the board. Find them through the Colorado Division of Local Affairs at dola.colorado.gov ^[5].

What property tax exemptions does Denver offer?

Three exemptions matter most for Denver homeowners.

Senior Citizen Property Tax Exemption: Colorado gives a partial exemption to homeowners 65 or older who have owned and lived in their primary residence for at least 10 straight years ^[6]. It removes 50% of the first $200,000 of actual value, which comes out to up to $100,000 off your assessed value. At Denver's current residential rate and a combined mill levy near 79 to 82 mills (it swings with school and special districts), that's roughly $500 to $700 a year in savings, more in some pockets.

The deadline is July 15 for the tax year that starts the following January 1. You file with the Denver Assessor. If you got the exemption last year, it renews on its own as long as you stay in the home and ownership doesn't change ^[6].

Disabled Veteran Property Tax Exemption: A veteran with a service-connected disability rated 100% permanent and total (or individual unemployability rated at 100%) gets the same 50% of the first $200,000 exemption ^[7]. No age requirement, no length-of-ownership requirement. A surviving spouse of a qualifying disabled veteran can claim it too. Apply through the Denver Assessor by July 15.

Temporary assessment rate reductions: The General Assembly has twice passed bills cutting the residential rate below its baseline. Senate Bill 23B-001, from a special session, dropped the 2023 residential rate to 6.765% for single-family and 6.8% for multi-family ^[2]. Watch for more of the same, because the legislature reaches for this tool when values spike. Check the Colorado Division of Property Taxation for the confirmed rate before each tax year.

Think you might qualify for the senior or veteran exemption? Apply even if you're not sure. The assessor reviews eligibility, there's no penalty for filing when you don't qualify, and not filing just leaves money on the table.

How do I look up my Denver property assessment online?

The Denver Assessor's property search lives at denvergov.org/assessor. Search by address, schedule number, or owner name. Pull up your parcel and you'll see:

• Actual value (the assessor's market value estimate)
• Assessed value (actual value times the assessment rate)
• Property characteristics: square footage, bedroom and bathroom count, lot size, year built, construction type, basement finish
• Sales history for your parcel
• Any exemptions already applied

Spend five minutes comparing those characteristics to your actual home. If the record says 2,100 square feet and your home is 1,850, that gap alone can carry a protest. If the record shows a finished basement and yours is unfinished storage, same deal. These aren't opinions about value. They're factual corrections the assessor has to make.

You can pull recent comparable sales from the same portal. Use the sales search, filter by neighborhood and date, and see what nearby homes actually sold for. The assessor's own data is fair game for your protest packet.

How does Denver's mill levy work and what is the total tax rate?

Your bill is your assessed value times the combined mill levy. One mill equals $1 of tax per $1,000 of assessed value. Denver has no single mill levy. It's a stack of levies from several taxing entities layered on your parcel: the City and County of Denver, Denver Public Schools, the Mile High Flood District (formerly the Urban Drainage and Flood Control District), the Scientific and Cultural Facilities District (SCFD), and sometimes a special improvement district depending on your address ^[8].

For 2023 tax bills (paid in 2024), total residential mill levies in Denver generally ran 79 to 85 mills depending on which school and special districts overlap your property. Denver Public Schools alone levied roughly 48 to 50 mills of that. The City and County's share ran about 10 to 12 mills.

A quick example with round numbers. A home with an actual value of $600,000, a rate of 6.765%, and a levy of 82 mills produces a bill near $3,329 a year ($600,000 x 0.06765 = $40,590 assessed; $40,590 x 0.082 = $3,328). Knock $50,000 off the actual value and you save roughly $277 a year at those rates. Real money across the two years the assessment applies.

Find your parcel's exact levies on your tax notice or through the Denver Treasurer's portal at denvergov.org/finance ^[8].

What evidence actually wins a Denver property tax appeal?

Three kinds of evidence win most residential appeals: comparable sales, factual corrections, and independent appraisals. That's roughly the order people reach for them, though not the order of raw persuasiveness.

Comparable sales are the workhorse because they cost nothing to gather. Find three to six homes that sold inside the assessor's look-back window (for 2025 assessments, sales from January 2023 through June 2024) and match yours in size, age, condition, and location, and that point to a lower value. Weight sales in your own neighborhood over ones farther out. Adjust in your head for differences: a comp with a two-car garage against your one-car garage warrants marking that comp's value down when you draw your conclusion.

Factual corrections hit hardest because they strip out the argument. If the record says 2,200 square feet of finished space and you actually have 1,850, you're not debating market conditions. You're fixing a database error. Bring your floor plan, permit records, or your original purchase listing. The assessor can't reasonably refuse a verifiable correction.

An independent appraisal is the strongest single piece of evidence, and it runs $400 to $700 for a residential property in Denver. Worth it if your assessment is inflated by more than $50,000 or you plan to carry the fight to the CBOE or BAA. For a small dispute, comps usually do the job.

Want a structured way to gather and present all this without handing a contingency firm 30 to 50% of your savings? The TaxFightBack DIY appeal kit walks through exactly what to pull and how to lay it out for Denver's protest form.

One thing to skip: the vague appeal that just says "my assessment seems too high." Assessors and boards see those all day and they go nowhere. Your protest needs a specific dollar conclusion and specific evidence under it.

How does Denver's assessment process compare to other major counties?

Denver reassesses every two years. That's less often than California's Proposition 13 counties, which only reassess on a sale, and more often than some others. The two-year cycle means your value can jump hard if the market moved a lot during the look-back window, which is exactly what hit Denver in 2023.

Colorado's residential rate of roughly 6.765 to 6.95% sits well below the commercial rate of 27.9%, a tax shift baked into the state constitution during the Gallagher Amendment years. Voters repealed Gallagher itself in 2020 through Amendment B ^[9]. The repeal froze the assessment rates at 2020 levels and handed the legislature the discretion to adjust them, which it has used more than once.

Other large urban counties with their own tangled appeal processes include Cook County, Illinois, Los Angeles County, California, and Maricopa County, Arizona, each with its own deadlines and evidence standards. Denver's process is easy to work by comparison: online filing is straightforward, the CBOE hearing is informal, and you really can represent yourself well.

Georgia's county assessors, like Gwinnett County, and Texas counties run on entirely different rules with annual appraisals and different protest windows. If you own property in more than one state, don't assume the Denver playbook carries over.

County	Reassessment frequency	Protest deadline	Assessment rate (residential)
Denver, CO	Every 2 years	June 8	6.765% (2023)
Cook, IL	Every 3 years by township	Various	10% (single-family)
Los Angeles, CA	On sale or new construction	Nov 30 or 60 days from notice	100% (Prop 13 capped)
Maricopa, AZ	Annual	April 25	10% (owner-occupied)
Gwinnett, GA	Annual	45 days from notice	40%

Sources: respective county assessor offices and state statutes ^{[1][3][10][11]}.

What if my Denver assessment jumped and I can't afford the tax?

Colorado runs a property tax deferral program that lets qualifying seniors (65+) and active military homeowners defer part of their tax until the property sells or the owner stops qualifying ^[12]. The deferred amount picks up interest at a low statutory rate and becomes a lien on the property. It isn't forgiveness. It protects your cash flow.

If you don't qualify for deferral, the protest and exemption routes above are your main levers. A protest that trims your actual value by $75,000 in Denver saves roughly $415 a year at current rates, across two tax years, so about $830 total from one win. Meaningful, but not life-changing unless your assessment is badly off.

If your value climbed because Denver's market genuinely rose, not because of an error, your case is harder. The assessor has to use the look-back sales, and if comparable homes really sold at those prices, the value can be technically right even when it stings. The legislative rate cuts are the political answer to exactly this, and what the General Assembly does in 2025 may matter as much as your individual protest.

Facing real hardship? Denver Human Services has resources worth checking, and property tax payment plans and assistance programs shift year to year, so call the Treasurer at 720-913-9300 to ask what's live now.

How can I contact the Denver County Assessor's office?

The Denver County Assessor has several ways in:

• Website: denvergov.org/assessor ^[1]
• Phone: 720-913-4162
• In person: 201 W. Colfax Ave., Department 406, Denver, CO 80202 (ground floor of the City and County Building)
• Hours: Generally Monday through Friday, 8 a.m. to 5 p.m., though check the website since post-pandemic schedules have moved around
• Online protest filing: Live through the assessor's portal during the protest window

For your tax bill, payment, or installment options, the Denver Treasurer is a separate office:

• Website: denvergov.org/finance
• Phone: 720-913-9300

To appeal after the assessor's decision (the CBOE stage), get the Denver County Board of Equalization contact through the assessor's office or the city's main site. CBOE filings go to the same address, addressed to the Board.

For a BAA appeal (the state-level next step), you file with the Colorado Board of Assessment Appeals at 1313 Sherman St., Denver, CO 80203, reachable through the Colorado Division of Local Affairs at dola.colorado.gov ^[5].

Want to build your own packet before filing? The TaxFightBack DIY appeal kit covers the Denver process, including which comps to pull and how to format the evidence for the online portal.

Frequently asked questions

When is the Denver property tax protest deadline in 2025?

The protest deadline is June 8, 2025. Notices of Valuation go out by May 1, and you get 30 days to file. Missing the date means you can't challenge the assessment behind your 2025 and 2026 tax bills. File early so you have time to gather comparable sales and other supporting evidence before the window closes.

How do I find my Denver property assessment online?

Go to denvergov.org/assessor and search by address, schedule number, or owner name. Your record shows actual value, assessed value, and the property characteristics (square footage, bedroom count, lot size, basement finish) the assessor used. Compare those to your actual home. Errors in the record are common and are the easiest basis for a winning protest.

What is the Denver residential property assessment rate?

For the 2023-2024 cycle, the Colorado General Assembly set the residential rate at 6.765% for single-family homes and 6.8% for multi-family under Senate Bill 23B-001. Prior cycles used 6.95%. The rate is applied to actual value to get assessed value, which is then multiplied by the mill levy for your bill. Confirm the current rate before each cycle.

Who is the Denver County Assessor?

As of this writing, the Denver County Assessor is Keith Erffmeyer, an elected official whose office is at 201 W. Colfax Ave., Department 406, Denver, CO 80202. The assessor estimates market values for all parcels, keeps property records, and runs the exemption programs. The assessor does not collect taxes; that's the Denver Treasurer's job.

Does Denver offer a senior property tax exemption?

Yes. Colorado's senior exemption removes 50% of the first $200,000 of actual value from taxable value for homeowners 65 or older who have owned and lived in their primary residence for at least 10 straight years. It can save $500 to $700 or more a year depending on location and mill levy. Apply by July 15 with the Denver Assessor.

Can a disabled veteran get a property tax break in Denver?

Yes. A veteran with a VA-rated service-connected disability of 100% permanent and total qualifies for the same break as seniors: 50% of the first $200,000 of actual value off taxable value. No age or length-of-ownership requirement. Surviving spouses of qualifying veterans are also eligible. Apply by July 15 with the Denver Assessor.

How often does Denver reassess property values?

Every two years, in odd-numbered years. A new cycle produces a Notice of Valuation mailed by May 1. In even years, you only get a notice if your value changed for a specific reason outside the biennial cycle, like new construction, a permit completion, or a correction. The two-year cycle means your value can shift sharply if the market moved during the look-back window.

What happens if I miss the Denver property tax protest deadline?

You lose the right to formally challenge the assessed value for that cycle, which covers two years of bills. Your only fallback is an abatement petition under C.R.S. §39-10-114, filed within two years of the tax year, which requires showing the assessment was erroneous or illegal, more than that it feels high. Abatements are harder to win than standard protests.

Do I need a lawyer or tax agent to appeal my Denver property assessment?

No. Colorado law lets you represent yourself at every stage: the assessor protest, the CBOE hearing, and the Board of Assessment Appeals. Most residential appeals turn on the quality of the evidence, not legal argument. A clean comp analysis and any factual corrections to your record beat a lawyer in most cases at the assessor and CBOE levels.

What sales data does the Denver Assessor use to set values in the 2025 cycle?

For the 2025 reappraisal, Colorado statute requires an 18-month look-back window ending June 30, 2024, so sales from roughly January 1, 2023 through June 30, 2024 anchor the 2025 values. When you build your protest, your comparable sales should come from that same window. Sales outside it carry less weight in the assessor's formal review.

Can I appeal my Denver property taxes if I just bought the house?

Yes, but timing matters. Bought during a protest window? File during it, using your purchase price as evidence of market value. Bought mid-cycle? Protest during the next open window in the following odd year, or file an abatement petition under C.R.S. §39-10-114 if the assessment is clearly wrong. Your sale price is legitimate evidence of value.

What is Denver's combined property tax mill levy?

Denver has no single citywide rate. Your levy is the sum from the city, Denver Public Schools, and several special districts, and it varies by parcel. For 2023 bills, most Denver residential parcels fell between 79 and 85 mills combined. Denver Public Schools makes up roughly 48 to 50 mills of that. Check your tax notice or denvergov.org/finance for your exact rate.

How long does a Denver property tax appeal take from filing to decision?

The initial assessor review must produce a written decision by August 15. Appeal to the CBOE and the board must rule by November 1. So from a June 8 filing to a final CBOE decision runs roughly five months. A further BAA appeal can add six to twelve months. Binding arbitration varies. Go all the way to the BAA and the full timeline can top a year.

Is the Denver Assessor the same as the county treasurer?

No. Separate offices. The Denver County Assessor estimates values and runs exemptions. The Denver Treasurer sends bills and collects payments. Question about your assessed value or how to protest it? Call the Assessor at 720-913-4162. Question about your bill amount, due dates, or payment plans? Call the Treasurer at 720-913-9300.

Sources

1. City and County of Denver Assessor's Office (official assessor portal, denvergov.org): Denver County Assessor office address, phone, online protest portal, and property search tool
2. Colorado General Assembly, Senate Bill 23B-001 (2023 Special Session): Temporary residential assessment rate set at 6.765% for single-family and 6.8% for multi-family for the 2023-2024 cycle
3. Colorado Revised Statutes §39-5-122, Colorado General Assembly: Notices of Valuation must be mailed by May 1; protest deadline is June 8 or 30 days after mailing
4. Colorado Revised Statutes §39-8-106 and §39-10-114, Colorado General Assembly: Assessor must mail decision by August 15; CBOE must rule by November 1; abatement petitions available within two years
5. Colorado Board of Assessment Appeals, via Colorado Division of Local Affairs: State-level appeal body for property tax disputes after CBOE; hears and publishes decisions
6. Colorado Division of Property Taxation, Senior Citizen Exemption guidance: Senior exemption: 50% of first $200,000 actual value exempt; must be 65+, owned 10 consecutive years; apply by July 15
7. Colorado Division of Property Taxation, Disabled Veteran Exemption guidance: 100% P&T disabled veterans qualify for same 50% of first $200,000 exemption with no age or tenure requirement
8. City and County of Denver, Office of the Treasurer (denvergov.org): Mill levy breakdown by taxing entity including city, DPS, and special districts; 2023 residential rates ranged roughly 79-85 mills
9. Colorado Secretary of State, Amendment B (2020 Ballot), Colorado Constitution: Voters repealed the Gallagher Amendment in 2020, freezing assessment rates at 2020 levels and giving legislature authority to adjust
10. Cook County Assessor's Office, cookcountyassessor.com: Cook County reassesses by township on a three-year rotating cycle; residential assessment rate is 10% for single-family
11. Maricopa County Assessor, mcassessor.maricopa.gov: Maricopa County assesses annually; owner-occupied residential assessment ratio is 10%; protest deadline is April 25
12. Colorado Division of Property Taxation, Property Tax Deferral Program guidance: Qualifying seniors 65+ and active military can defer property taxes; amount accrues interest and becomes lien until property sold
13. Gwinnett County, Georgia (official county site, gwinnettcounty.com): Gwinnett County assesses annually at 40% of fair market value; protest window is 45 days from notice