4.40% flat income tax (no local income taxes, TABOR-protected constitutional rate)
Colorado has a 4.40% flat income tax on all taxable income, with no local income taxes anywhere in the state. At $100,000 income, you pay exactly $4,400 in Colorado state tax. This rate decreased from 4.55% in 2023 and is protected by TABOR (Taxpayer Bill of Rights), which requires voter approval for any tax increases.
Colorado has a 4.40% flat income tax that applies to all Colorado taxable income regardless of income level. This is one of the simplest tax structures in America - no brackets, no phaseouts, no complexity. A $40,000 earner and a $400,000 earner both pay exactly 4.40% on their Colorado taxable income.
Critical advantage: NO local income taxes. Unlike Pennsylvania (Philly adds 3.79%), Ohio (cities add 0.5-3%), or New York (NYC adds 3.078-3.876%), Colorado has ZERO local income tax anywhere in the state. Whether you live in Denver, Boulder, Colorado Springs, Aspen, or rural counties, you pay only the 4.40% state rate. This makes Colorado extremely simple for remote workers and businesses operating across multiple cities.
Recent rate changes:
Why the rate decreased: Colorado's TABOR (Taxpayer Bill of Rights) constitutional amendment limits state revenue growth to inflation + population growth. When revenue exceeds the cap, Colorado must either refund money to taxpayers OR reduce the tax rate. In 2023, Colorado reduced the flat tax rate from 4.55% to 4.40% - saving taxpayers approximately $750 million annually.
TABOR protection explained: TABOR is a 1992 constitutional amendment that requires voter approval for ANY tax increase above inflation + population growth. This means Colorado's 4.40% rate cannot increase without a statewide vote. Since 1992, Colorado voters have rejected most tax increase proposals, keeping rates stable for 30+ years. This gives businesses and residents long-term tax certainty that most states lack.
Source: Colorado Department of Revenue - Individual Income Tax
Here's what Colorado Flat Tax residents actually pay at different income levels (2026, single filer, standard deduction):
| Annual Income | Federal Tax | State Tax | Total Tax | Take-Home Pay | Effective Rate |
|---|---|---|---|---|---|
| $50,000 | $4,166 | $2,200 | $6,366 | $43,634 | 12.7% |
| $75,000 | $8,340 | $3,300 | $11,640 | $63,360 | 15.5% |
| $100,000 | $12,908 | $4,400 | $17,308 | $82,692 | 17.3% |
| $150,000 | $25,218 | $6,600 | $31,818 | $118,182 | 21.2% |
| $250,000 | $54,094 | $11,000 | $65,094 | $184,906 | 26.0% |
Note: Includes federal and state income tax only. Does not include FICA (Social Security/Medicare), which adds 7.65% for employees.
Key takeaway: At $100K, Colorado Flat Tax takes $4,400 in state tax alone.
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Get Matched With a CPA →California → Colorado migration surge: According to U.S. Census Bureau data (2021-2023), over 30,000 Californians move to Colorado annually (net migration after accounting for CO→CA moves). This is the largest California refugee flow to any mountain state, driven by tax savings, lower cost of living, and outdoor lifestyle.
Tax savings for California refugees at $100,000 income:
But the real savings come from property taxes:
Total California → Colorado savings at $100K income + homeownership:
At $150,000 income (common for tech workers):
Why Californians choose Colorado over other low-tax states:
The Denver/Boulder tech hub: Colorado's Front Range (Denver-Boulder corridor) has emerged as a major tech hub with companies like:
Remote worker advantages: Colorado's flat 4.40% tax with NO local taxes makes it ideal for remote workers compared to:
| State | Tax Rate | Tax on $100K Income | Difference from Colorado Flat Tax |
|---|---|---|---|
| Colorado | 4.40% flat | $4,400 | Baseline |
| California | 1-13.3% | $5,762 | +$1,362 (more tax) |
| Texas | 0% | $0 | -$4,400 (less tax) |
| Washington | 0% | $0 | -$4,400 (less tax) |
| Arizona | 2.5% flat | $2,500 | -$1,900 (less tax) |
| Utah | 4.65% flat | $4,650 | +$250 (more tax) |
Key insight: Colorado's 4.40% flat tax sits in the middle of competing Western states. It's higher than Arizona (2.5%), Texas (0%), and Washington (0%), but significantly lower than California (6.27% effective at $100K). The value proposition: pay a moderate 4.40% tax for access to Denver/Boulder job market + world-class outdoor recreation without California's 9.3%+ rates.
The "outdoor lifestyle tax" - is 4.40% worth it vs 0% states?
Break-even analysis at $100,000 income:
Salary adjustment reality: Denver tech salaries run 15-25% below Seattle and 20-30% below SF Bay Area for identical roles. Example: Senior Software Engineer at Google:
Net calculation for Google SWE relocating SF → Denver:
Verdict: Colorado's 4.40% flat tax makes sense for California refugees seeking lower cost + outdoor lifestyle while maintaining white-collar job access. Texas/Washington offer better pure tax savings, but Colorado balances tax efficiency with lifestyle quality and job market strength. The 4.40% is the "price of admission" to Colorado's outdoor paradise with major metro job market - most find it worth paying vs 9.3%+ California rates.
Yes. Colorado has a 4.40% flat income tax that applies to all Colorado taxable income regardless of income level. There are no tax brackets - everyone pays exactly 4.40% on their taxable income after deductions. This rate decreased from 4.55% in 2023 and is protected by TABOR (Taxpayer Bill of Rights), which requires voter approval for any tax increases. Colorado is one of only 9 flat-tax states in the US.
At $100,000 income: save $1,362/year state income tax (CA $5,762 vs CO $4,400) + approximately $2,659/year property tax (CA 0.74% vs CO 0.49% average). Total annual savings: $4,021/year. At $150,000 income: save $4,162/year income tax + $3,988/year property tax = $8,150/year total. Over 5 years at $150K: $40,750 in tax savings plus $160K less for median home = $200K+ wealth preservation. However, Denver tech salaries run 20-30% below SF Bay Area, so factor in potential salary decrease.
TABOR (Taxpayer Bill of Rights) is a 1992 Colorado constitutional amendment that limits state revenue growth to inflation + population growth. Any revenue exceeding the cap must be refunded to taxpayers or offset by rate reductions. TABOR requires voter approval for tax increases above the limit. This protection means Colorado's 4.40% rate cannot increase without a statewide vote - providing long-term tax certainty. In 2023, TABOR forced Colorado to reduce the rate from 4.55% to 4.40%, saving taxpayers $750 million annually.
No. Colorado has ZERO local income taxes anywhere in the state. This is a huge advantage over states like Pennsylvania (Philly adds 3.79%), Ohio (cities add 0.5-3%), or New York (NYC adds 3.078-3.876%). Whether you live in Denver, Boulder, Colorado Springs, Aspen, or rural counties, you pay only the 4.40% state rate. This makes Colorado extremely simple for remote workers and businesses operating across multiple cities - you never worry about crossing city tax boundaries.
Colorado (4.40% flat) is competitive regionally but not the lowest. Wyoming: 0% (saves $4,400/year at $100K but limited job market). Utah: 4.65% flat (CO saves $250/year at $100K). Arizona: 2.5% flat (AZ saves $1,900/year at $100K). New Mexico: 1.7-5.9% progressive (similar at $100K). Texas: 0% (saves $4,400/year but property tax 1.6% vs CO 0.49%). Colorado's advantage: Denver/Boulder major job market + outdoor lifestyle justify 4.40% tax vs Wyoming/Texas limited economies.
It depends on priorities. Colorado 4.40% costs $4,400/year at $100K income vs $0 in TX/WA. But factor in: (1) Property tax: TX 1.6% hurts homeowners (CO 0.49% much lower). (2) Lifestyle: CO offers world-class skiing, hiking, 300 sunny days - TX hot/humid, WA rainy. (3) Quality of life: Denver/Boulder culture, restaurants, educated workforce (42.7% bachelor's degree+). For remote workers earning $100K+ who value outdoor recreation and don't need maximized tax savings, CO's 4.40% is worth it. For pure tax optimization, choose TX (but budget extra $3,500/year property tax on typical home).
Partially. Social Security: Colorado taxes SS income if you're under 65 OR (if 65+) your federal AGI exceeds $75K single/$95K married. At age 65+ with income under thresholds, SS is fully exempt. Pension/401k: Taxed at 4.40% for all ages, but age 55-64 can deduct up to $20K/year, age 65+ can deduct up to $24K/year. Example: Age 66 with $40K SS + $60K pension = $100K total. SS fully exempt if married under $95K AGI, pension taxed on $36K (after $24K deduction) = $1,584 CO tax. Better than CA ($5,762 at $100K) but worse than TX/FL/NV (0%).
Colorado's average property tax rate is 0.49% - the 7th lowest in the United States. On a $590K Denver median home: $2,891/year property tax. Compare to: California 0.74% ($5,550/year on $750K home), Texas 1.6% ($6,400/year on $400K home), Utah 0.57% ($2,622/year on $460K home), Washington 0.8% ($6,600/year on $825K Seattle home). Combined with 4.40% income tax, Colorado offers very competitive total tax burden for homeowners. The low property tax offsets the moderate income tax, especially vs TX/WA where 0% income tax comes with brutal property taxes.
Only if working 100% remotely for an out-of-state employer. Colorado taxes all income earned while a CO resident, and taxes income earned in Colorado even for nonresidents. If you live in Cheyenne WY (45 min to Denver) and commute to a Denver office, you pay CO 4.40% tax on your CO wages - no savings. Wyoming residency only helps if you work remotely for a company with no CO nexus. This saves $4,400/year at $100K income but requires true WY residency: 6+ months/year in WY, WY voter registration, WY driver's license. Consult a CPA before attempting this strategy.
Simple 3-step calculation: (1) Start with your federal adjusted gross income (AGI). (2) Subtract Colorado standard deduction ($13,850 for single filers in 2026, $27,700 married filing jointly) to get Colorado taxable income. (3) Multiply Colorado taxable income by 4.40% (0.044). Example at $100,000 gross income, single filer: $100,000 AGI - $13,850 standard deduction = $86,150 taxable income × 4.40% = $3,791 Colorado tax. Note: Most online calculators (including ours) show estimates before deductions for simplicity.
How we calculate: Colorado's 4.40% flat tax makes calculations straightforward: we apply 4.40% to Colorado taxable income (federal AGI minus Colorado standard deduction of $13,850 single/$27,700 married in 2026). Our calculator combines this state tax with federal tax using official 2026 IRS brackets. We calculate effective tax rates by dividing total tax by gross income. For comparison purposes, we show other states' tax calculations at identical income levels using their official 2026 brackets and rates.
Data sources:
Verification: Colorado's 4.40% flat tax rate verified against Colorado Revised Statutes Title 39 Article 22 (Income Tax) and Colorado Department of Revenue 2026 Individual Income Tax Guide published January 2026. TABOR constitutional provisions verified against Colorado Constitution Article X Section 20. Migration data verified against IRS Statistics of Income (SOI) Tax Stats via Census Bureau. Property tax averages calculated from Lincoln Institute of Land Policy 50-State Property Tax Comparison Study (2025 edition). Federal bracket accuracy verified against IRS Revenue Procedure 2025-58 (2026 inflation adjustments).
California comparison calculations: California effective tax rates at various income levels calculated using California Franchise Tax Board 2026 tax tables. $100K income California tax of $5,762 assumes single filer using standard deduction ($5,363 CA standard deduction 2026). Colorado savings calculations verified: $5,762 CA - $4,400 CO = $1,362 annual savings. Property tax comparisons use median home prices from Zillow Home Value Index (January 2026) and Tax Foundation state property tax data.
Limitations: Assumes single filer with W-2 wage income only, standard deduction (not itemized), full-year Colorado residency. Does not include: Colorado-specific deductions (pension/Social Security exemptions for ages 55+/65+, charitable contributions to qualifying organizations, 529 plan contributions), federal tax credits (EITC, child tax credit), part-year or nonresident calculations, self-employment tax, local sales tax variations (2.9% state + 0-8.3% local = up to 11.2% in mountain resort towns), property tax variations by county (Front Range suburbs 0.4-0.6%, mountain resort counties 0.2-0.5%). Remote worker calculations assume 100% income taxed by state of residency - multi-state taxation requires professional analysis.
For complex situations: Consult a licensed Colorado CPA or tax attorney, especially for: part-year residency (Colorado taxes income earned while CO resident), multi-state income allocation (remote workers for California employers - CA may claim tax on CA-source income), Social Security taxation (complex rules based on age and AGI thresholds), pension deductions (age-specific limits), rental property income (depreciation, passive loss rules), business income (pass-throughs taxed at 4.40% individual rate), TABOR refund calculations in high-revenue years, Wyoming residency strategies to avoid CO tax while working remotely.
These calculations are estimates for informational purposes only and reflect 2026 Colorado tax law (4.40% flat rate on Colorado taxable income). Actual tax liability varies based on filing status, deductions, credits, income types, and residency status. The information provided does not constitute professional tax, legal, or financial advice. Colorado tax law is subject to TABOR constitutional restrictions (requiring voter approval for tax increases above inflation + population limits), but rates can still change through voter referendums. Does not include: local sales tax variations (2.9% state + 0-8.3% local), property tax variations by county, Colorado-specific deductions (pension/Social Security exemptions age 55+/65+, charitable contributions, 529 plans), TABOR refunds in high-revenue years, or multi-state taxation issues for remote workers. Federal tax laws change annually. Always verify current rates with the Colorado Department of Revenue and IRS, and consult a licensed tax professional for advice specific to your situation, especially for California → Colorado moves involving potential dual-state taxation, part-year residency, or complex retirement income scenarios.
Last Updated: March 2026
Verified By: CountryTaxCalc Research Team
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Last Updated: March 2026