Colorado Income Tax Guide 2026: The Flat 4.40% Rate Explained
This Colorado income tax guide 2026 explains the flat 4.40% rate, what counts as taxable income, and how Colorado compares to its neighbors.
Colorado taxes income at a flat 4.40% — no brackets, no local income tax, no marriage penalty in the rate itself. A single filer at $80,000 owes $2,811.60, and a married couple at $150,000 owes $5,183.20. The only real work is figuring out your taxable income, which Colorado borrows from your federal return.
This guide answers the questions Colorado taxpayers actually ask: how the flat rate works, what counts as Colorado taxable income, how the rate got to 4.40%, and how Colorado compares to its neighbors. Run your own numbers with the free Colorado income tax calculator.
What is Colorado’s income tax rate in 2026?
Colorado’s individual income tax rate is a flat 4.40% for 2026, set by statute (Colo. Rev. Stat. 39-22-104). Every dollar of Colorado taxable income is taxed at 4.40% — the first dollar and the millionth dollar alike. There are no brackets to climb, no marriage penalty in the rate, and no separate rate for capital gains or other income types.
That simplicity is the point. Your marginal rate and your average rate on taxable income are identical at 4.40%; only the standard deduction makes your effective rate on gross income lower — 3.51% at $80,000 single, 3.46% at $150,000 joint. If your income doubles, your Colorado tax doubles, with no bracket surprise waiting.
What counts as Colorado taxable income?
Colorado starts from your federal taxable income — gross income minus the federal standard or itemized deduction — and then applies Colorado additions and subtractions. For 2026, the federal standard deduction is $16,100 single, $32,200 joint, and $24,100 head of household. That is the deduction the Colorado income tax calculator uses unless you enter larger itemized deductions.
Colorado additions and subtractions then adjust the number: the pension and annuity subtraction helps qualifying retirees, and 529 plan contributions can reduce Colorado income. Those adjustments are not modeled in the basic calculator, so retirees and savers may owe less than the flat-rate math shows. No Colorado city or county levies an income tax, so the state return is the whole story.
How did Colorado’s rate get to 4.40%?
Colorado voters cut the rate twice by initiative: from 4.63% to 4.55% in 2020 (Proposition 116), then to 4.40% in 2022 (Proposition 121). Both cuts were flat-rate reductions, so every taxpayer benefited proportionally. There is no further cut scheduled for 2026 — another reduction would require another vote, and Colorado’s TABOR revenue cap complicates the politics of any future cut.
TABOR itself deserves a note: the Taxpayer’s Bill of Rights caps state revenue growth and can trigger refunds when collections exceed the cap. Those refunds arrive as separate payments or temporary mechanisms — they do not change the 4.40% rate, but they are a real part of Colorado’s tax picture in surplus years.
How much Colorado tax do you pay on $80,000?
A single filer earning $80,000 with no itemized deductions owes $2,811.60 for 2026 — an effective rate of 3.51%. Subtract the $16,100 federal standard deduction for $63,900 of Colorado taxable income, then multiply by 4.40%. A married couple at $150,000 owes $5,183.20 on $117,800 of taxable income.
- Gross income: $80,000
- Federal standard deduction (single): −$16,100
- Colorado taxable income: $63,900
- Colorado tax (4.40%): $2,811.60
- Effective rate: 3.51%
The comparison that sells Colorado: the same $80,000 earner owes $5,725.88 in Oregon (with no federal subtraction) and $3,916.61 in Minnesota. Colorado’s flat rate is roughly half the Oregon bill and about 30% below Minnesota’s — before any Colorado subtractions are counted.
Does Colorado tax retirement income?
Partly, with meaningful relief. Colorado offers a pension and annuity subtraction for qualifying retirees — up to $20,000 per taxpayer under 65 and $24,000 at 65 and older — which can cut the taxable base substantially. Social Security benefits follow the federal treatment, and military retirement pay has its own subtraction provisions.
Those subtractions are why the basic calculator can overstate a retiree’s bill: it uses federal taxable income without Colorado’s retirement adjustments. If you are retired in Colorado, run the return with the subtractions before concluding anything from the flat-rate math — the difference can be several hundred dollars.
How does Colorado compare to Arizona and Utah?
Colorado sits between its flat-tax neighbors: Arizona charges a flat 2.5% — the lowest flat rate in America — while Utah charges a flat 4.55% in recent years. At $80,000 single, Arizona’s bill is $1,597.50 versus Colorado’s $2,811.60, a gap driven entirely by the rate, since both states use the same federal-sized standard deduction.
Against graduated-rate neighbors the gap is wider in Colorado’s favor: New Mexico’s top rate is 5.9% and Kansas reaches 5.7%, both with narrower deductions. Colorado’s combination — a moderate flat rate, a full federal deduction, and no local income tax — makes it one of the simpler and cheaper states for wage earners. Compare directly with the Arizona income tax calculator and the state income tax calculator hub.
What else do Colorado taxpayers ask?
When is my 2026 Colorado return due?
April 15, 2027. Colorado returns are filed on Form DR 0104, and estimated payments are due quarterly if withholding does not cover your liability — relevant for freelancers and anyone with significant non-wage income.
Does Colorado have a state earned income credit?
Yes. Colorado offers a refundable earned income credit equal to a percentage of the federal credit, plus a state child tax credit for qualifying families. Neither is included in the basic calculator, so eligible families may owe less than shown.
Do I pay Colorado tax if I work remotely for an out-of-state employer?
Generally yes, if you are a Colorado resident — Colorado taxes residents on all income wherever earned, with a credit for taxes paid to other states. Nonresidents pay only on Colorado-source income.
What is TABOR and does it change my rate?
TABOR (the Taxpayer’s Bill of Rights) caps state revenue growth and can trigger refunds in surplus years. It does not change the 4.40% rate itself — refunds arrive as separate payments or temporary mechanisms.
Estimates only — not tax advice. Verify with the Colorado Department of Revenue or a tax professional.
