Denver Colorado Tax Guide 2026: State Flat Tax, Denver OPT, and Total Burden

Colorado's tax environment stands out for its combination of a genuinely low flat income tax rate and a constitutional mechanism — the Taxpayer's Bill of Rights (TABOR) — that automatically returns excess tax revenue to citizens. Colorado's flat 4.4% income tax rate is one of the lowest flat rates among states that levy income tax, placing Colorado firmly in the 'tax-competitive' category alongside states like Arizona (2.5%) and North Carolina (3.99%).

Denver, as Colorado's capital and largest city, levies a nominal Occupational Privilege Tax (OPT) of $5.75 per month on employees — just $69 per year — rather than a full city income tax. This is negligible compared to NYC's 3.876% city income tax or Philadelphia's 3.75% Wage Tax. Denver's overall tax burden, combining the state flat tax, the OPT, sales taxes, and property taxes, makes it one of the more affordable major US cities from a pure tax perspective, while still offering the amenities and economic opportunities of a major metro.

Colorado's Flat 4.4% Income Tax Explained

Colorado's state income tax is a flat 4.4% applied to Colorado taxable income, which generally follows federal adjusted gross income with Colorado-specific modifications. The rate was reduced from 4.55% in 2022 (effective for tax year 2022) under House Bill 22-1406, and the reduction was made permanent. The 4.4% rate applies to all Colorado taxpayers regardless of income level — there are no brackets.

Colorado's TABOR amendment (Article X, Section 20 of the Colorado Constitution) adds an unusual feature: when Colorado's state revenue exceeds a cap based on population growth plus inflation, the surplus must be refunded to taxpayers. In practice, TABOR refunds have been common in recent years during strong economic growth, effectively reducing the net income tax rate below 4.4%. For tax year 2023, for example, Colorado issued TABOR refunds of approximately $800 per taxpayer. These refunds are not guaranteed annually — they depend on revenue exceeding the cap — but they have occurred frequently enough to be a real benefit to Colorado taxpayers.

Denver's Occupational Privilege Tax (OPT)

Denver's Occupational Privilege Tax is among the most modest local income-related taxes in any major US city. Workers employed in Denver who earn at least $500 in a calendar month pay $5.75 per month ($69 per year) as an employee OPT. Employers also pay $4 per month per Denver employee (the employer OPT). Both the employee and employer portions are flat amounts — they do not increase with income. A software engineer earning $200,000 in Denver pays the exact same $69/year OPT as a restaurant worker earning $25,000.

Denver is not unique in having an OPT — Aurora, Glendale, Greenwood Village, Sheridan, and other Colorado municipalities also levy OPT-type taxes, typically ranging from $2 to $10 per month. For comparison, New York City workers at $100,000 pay approximately $3,794 per year in city income tax. Denver's $69/year OPT is barely 2% of that amount. The OPT's primary purpose is administrative — creating a low-friction local revenue mechanism — rather than a major revenue source.

Sales Tax in Denver 2026

Denver's combined sales tax rate of approximately 8.81% is assembled from multiple overlapping jurisdictions:

Colorado's 2.9% state sales tax rate is one of the lowest state base rates in the country — notably lower than California (7.25%), Illinois (6.25%), or Washington (6.5%). Denver's local additions bring the combined rate to 8.81%, which is moderate by major city standards. Groceries are subject to Denver's city sales tax but exempt from the Colorado state portion — a partial mitigation for food purchases.

Colorado Property Tax and the Gallagher Amendment Legacy

Colorado's residential property tax system was shaped for decades by the Gallagher Amendment (1982-2020), which required residential property to generate a fixed share of statewide property tax revenue. As home values rose faster than commercial values, the residential assessment rate was repeatedly adjusted downward — falling from 21% of actual value to just 7.2% by 2020. Colorado voters repealed the Gallagher Amendment in 2020 (Proposition 116), freezing the assessment rate at the Gallagher-reduced level of approximately 7.15% of actual value for residential property.

The property tax calculation in Colorado: assessed value = actual (market) value × 7.15% assessment rate. The mill levy (set by each taxing entity) is then applied to the assessed value. For a $600,000 Denver home, assessed value is $42,900. At a typical Denver combined mill levy of approximately 80 mills ($80 per $1,000 assessed), annual property tax is approximately $3,432. This is notably lower than comparable Texas or Illinois property tax bills, reflecting Colorado's low assessment ratio even after Gallagher's repeal.

Denver vs Other Major Cities: Total Tax Burden

For a single professional earning $100,000 and renting in Denver:

Denver's total burden is competitive with other major western cities. It is higher than no-income-tax destinations (Seattle, Austin) but lower than Chicago and significantly lower than NYC or San Francisco. Denver's combination of low flat tax rate, nominal OPT, moderate sales tax, and low property assessment ratio makes it one of the more favorable major US metros for income-earners seeking a balance of tax efficiency and quality of life.