Yes, Colorado has a state income tax
Colorado charges a flat state income tax on wages, investment income, and other earnings. The rate is 4.63% as of 2024, applied to your federal taxable income after certain adjustments. This is lower than the national average state income tax rate, but it still means you owe Colorado money on top of what you pay the federal government.
If you live in Colorado or earned income there, you will file a Colorado state tax return alongside your federal return. The state uses a simpler system than the IRS — you cannot itemize deductions on your state return, and the tax brackets do not change based on filing status the way federal brackets do. This makes the Colorado calculation straightforward once you know your federal taxable income.
Colorado also taxes capital gains, retirement distributions, and business income at the same 4.63% rate. Military pensions and some federal pensions receive special treatment and may be partially or fully exempt, but most other income sources are taxed.
Key Takeaways
- Colorado's state income tax rate is a flat 4.63% on federal taxable income, with no variation by income level or filing status.
- You must file a Colorado state return if you lived in the state on December 31 of the tax year or earned income there, even if you owe no tax.
- Colorado does not allow itemized deductions on state returns; you use the same federal taxable income figure for both returns.
- Military pensions and certain federal pensions are exempt from Colorado state tax, but you must claim the exemption on your return.
- Colorado taxes capital gains, retirement account withdrawals, and self-employment income at the same 4.63% rate as wages.
Who must file a Colorado state return
You must file if you lived in Colorado on December 31 of the tax year, regardless of income. You also must file if you earned income in Colorado but lived elsewhere — for example, if you worked remotely for a Colorado company while living in another state. The state considers you a resident for tax purposes if you maintained a permanent home there, even if you spent part of the year out of state.
The income threshold for filing varies by age and filing status. A single person under 65 with less than $14,600 in income (2024 figures) generally does not have to file, but many people file anyway because they are owed a refund. If you had Colorado income tax withheld from paychecks or made estimated tax payments, filing is the only way to recover that money.
Part-year residents — people who moved to or from Colorado during the year — must file if they meet the income threshold for the portion of the year they lived there. You report only the income earned while you were a Colorado resident.
How Colorado income tax is calculated
Colorado starts with your federal taxable income, the number you report on line 15 of your federal Form 1040. The state then makes a few adjustments — adding back certain deductions the IRS allows but Colorado does not, and subtracting certain income Colorado exempts. The most common adjustment is the military pension exemption: if you received a military pension, you subtract up to $24,000 of it (2024 limit) before calculating state tax.
After adjustments, you explore the flat 4.63% rate. There are no brackets, no phase-outs, and no credits that reduce the tax itself — only a few narrow deductions. This means a person earning $50,000 pays the same percentage as someone earning $500,000. The calculation is genuinely straightforward: take your adjusted income, multiply by 0.0463, and that is your Colorado income tax before any credits.
Colorado offers a few tax credits that reduce what you owe, such as the Earned Income Tax Credit (which mirrors the federal version) and credits for property taxes or rent paid. These credits are claimed on your state return and can lower your final tax bill below the flat 4.63% calculation.
Colorado income tax withholding and estimated payments
If you are a Colorado employee, your employer withholds state income tax from each paycheck using a W-4 form you complete. The withholding is based on the information you provide — your filing status, number of dependents, and other income. If your withholding is too high, you get a refund when you file. If it is too low, you owe money.
Self-employed people and those with investment income often make quarterly estimated tax payments to Colorado. These are due April 15, June 15, September 15, and January 15 (of the following year). The Colorado Department of Revenue provides a worksheet to calculate the amount, and you can pay online through their website or by mail.
If you moved to Colorado mid-year or had a major life change, you can adjust your withholding by submitting a new W-4 to your employer. This prevents overpaying or underpaying for the rest of the year.
Special situations: Military, pensions, and out-of-state income
Military pensions are exempt from Colorado state tax up to $24,000 per year (2024). If your military pension exceeds that amount, only the excess is taxed. You claim this exemption on your Colorado return by subtracting the exempt amount from your income before calculating tax. Federal pensions and some other government pensions may also may have access to for partial exemptions — check the Colorado Department of Revenue website or your tax software for your specific pension type.
If you earned income in another state while living in Colorado, you may owe tax to both states. Colorado taxes all income of residents, including out-of-state wages. However, most states offer a credit for taxes paid to other states, so you do not pay double. You will file a return in the other state showing the income earned there, pay that state's tax, and then claim a credit on your Colorado return for the tax you paid elsewhere.
Retirees who moved to Colorado from another state should review their pension and Social Security treatment. Colorado does not tax Social Security benefits, which is a significant advantage over some other states. Retirement account withdrawals (from IRAs, 401(k)s, and similar accounts) are taxed as ordinary income at the 4.63% rate.
Where to file your Colorado state return
You file your Colorado return with the Colorado Department of Revenue, not with the IRS. Most tax software (TurboTax, H&R Block, TaxAct) includes Colorado state forms and will file electronically on your behalf. You can also read the forms from the Colorado Department of Revenue website and mail them in, though electronic filing is faster and reduces errors.
The filing important date is April 15 of the year following the tax year, the same as the federal important date. If you file your federal return late, your Colorado return is also late. You can request an extension by filing Form 4868 with the IRS; Colorado honors the federal extension automatically.
If you owe Colorado tax, you can pay online, by mail, or through your tax software. Payments made by the April 15 important date avoid penalties and interest. If you cannot pay in full, the Colorado Department of Revenue offers payment plans — contact them directly to arrange one.
Frequently Asked Questions
Do I have to file a Colorado state return if I only lived there part of the year?
Yes, if you lived in Colorado on December 31 of the tax year, you must file a full-year return reporting all your income. If you moved to Colorado during the year, you file a part-year return reporting only income earned after you arrived. If you moved out of Colorado during the year, you file a part-year return reporting only income earned before you left.
Is Social Security taxed in Colorado?
No. Colorado does not tax Social Security benefits, even if you have other income. This is one of the few income sources completely exempt from state tax. You still report Social Security on your federal return, but you subtract it entirely on your Colorado return.
What if I worked in Colorado but lived in another state?
You must file a Colorado return reporting the income you earned there. You also file a return in your home state. Most states allow you to claim a credit for taxes paid to Colorado, so you do not pay the full rate in both states. Check your home state's rules on nonresident income and out-of-state tax credits.
Can I deduct my mortgage interest or charitable donations on my Colorado return?
No. Colorado does not allow itemized deductions or the standard deduction the way the federal return does. You use your federal taxable income as the starting point, which already reflects those deductions. You cannot deduct them again on your state return.
What happens if I do not file a Colorado state return when I should have?
The Colorado Department of Revenue can assess penalties and interest on unpaid tax. If you owed tax and did not file, penalties start at 5% of the unpaid amount per month, up to 25%. Interest accrues daily. If you realize you missed a year, file as soon as possible — the sooner you file, the less interest accumulates.