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2026 Colorado Income Tax Guide

Flat 4.40% base rateApplied to Colorado taxable income before applicable credits.
Federal starting pointColorado generally begins with federal taxable income and applies state modifications.
Resident planning estimateThe calculator is designed primarily for full-year residents with common wage income.
Official Sources Colorado DOR IRS SSA
Colorado DOR IRS SSA
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How Colorado taxes work

Colorado taxable incomeThe state generally starts with federal taxable income, then applies Colorado additions and subtractions.
Flat state rateThe calculator applies Colorado’s 4.40% base individual income-tax rate as a planning model.
Federal and payroll taxesFederal income tax, Social Security, and Medicare are calculated separately using supported 2026 rules.
Residency mattersResidents are generally taxed on income from all sources; nonresidents are generally taxed on Colorado-source income.

Common Colorado tax questions

Is Colorado income tax progressive?No. Colorado applies a flat individual income-tax rate to Colorado taxable income rather than using multiple state tax brackets.
Are local Colorado taxes included automatically?No. Add a local income-tax rate in the calculator only when it applies to your situation; occupational and other local taxes can follow different rules.
How is the federal overtime deduction treated?For 2026, Colorado requires an addback for the federal overtime deduction, while qualified-tip deductions are treated differently.
Are all credits and modifications included?No. Your return may include additions, subtractions, credits, or local obligations not captured by this quick estimate.
Is this the same as a Colorado tax return?No. It is a planning estimate and does not prepare Form DR 0104 or account for every Colorado modification and credit.