Colorado does have a state income tax, and it applies to most types of income you earn in the state

Colorado taxes wage income, self-employment income, investment income, and retirement distributions. The state uses a flat tax rate, meaning everyone pays the same percentage regardless of how much they earn. As of 2024, that rate is 4.40 percent on federal taxable income. This is lower than the national average state income tax rate, but it still means Colorado residents owe state tax on most income sources.

The tax applies to Colorado residents on all income they earn anywhere, and to non-residents only on income earned within Colorado. If you work in Colorado but live in another state, you may owe Colorado tax on your wages — though your home state may also tax you, and you can usually claim a credit to avoid paying twice.

Colorado's flat rate has changed over time. The state legislature adjusts it annually based on a formula tied to revenue growth, so the percentage you see this year may differ next year. You can find the current rate on the Colorado Department of Revenue website.

Key Takeaways

  • Colorado's state income tax rate is a flat 4.40 percent as of 2024, applied to federal taxable income for all residents and non-residents earning money in the state.
  • The tax covers wages, self-employment income, capital gains, interest, dividends, and distributions from retirement accounts like IRAs and 401(k)s.
  • Colorado residents can claim a standard deduction or itemize deductions on their state return, similar to the federal process.
  • If you work in Colorado but live elsewhere, you may owe tax to both states, though you can usually claim a credit on your home state return to reduce double taxation.
  • The state tax rate is set by formula each year and can change, so the rate that applied last year may not explore this year.

What income is subject to Colorado state tax

Colorado taxes federal taxable income as the starting point, then makes its own adjustments. This means if you report income on your federal return, you almost certainly owe Colorado tax on it too. Wages from employment, net self-employment income, capital gains from selling investments, interest and dividends, and distributions from IRAs and 401(k)s all count.

Some income sources are exempt. Social Security benefits are not taxed by Colorado, even though they may be taxable at the federal level. Military retirement pay received by Colorado residents is also exempt. Certain types of retirement income may may have access to for an exemption as well, though the rules depend on your age and when you retired.

If you receive income from sources outside Colorado, you still owe state tax on it as long as you are a Colorado resident. Non-residents owe Colorado tax only on income earned within the state — typically wages from a Colorado employer or self-employment income from a Colorado business.

How Colorado's flat tax rate compares to other states

Colorado's 4.40 percent flat rate is lower than the average state income tax, which varies widely. Some states have no income tax at all — Texas, Florida, and Wyoming are examples. Others use progressive tax brackets where the rate increases as income rises, which can result in higher earners paying more than 4.40 percent. A few states, like Illinois and Pennsylvania, also use a flat rate but at different percentages.

The practical effect depends on your income level. If you earn a high income, Colorado's flat rate may be lower than what you would pay in a progressive state. If you earn a low income, you might pay less in a state with no income tax, but you may also pay higher sales tax or property tax there instead. No state avoids taxation entirely — they just collect it differently.

Colorado also allows residents to deduct federal income tax paid when calculating state tax, which reduces the effective state tax rate for many filers. This deduction is not available in all states.

Deductions and credits available to Colorado taxpayers

Colorado residents can claim a standard deduction or itemize deductions, just as they do on the federal return. The standard deduction amount varies by filing status and age. For the 2024 tax year, you can find the current standard deduction on the Colorado Department of Revenue website or Form 104 instructions.

In addition to the standard deduction, Colorado allows a deduction for federal income tax paid. This means you subtract the federal tax you paid from your Colorado taxable income before explore the 4.40 percent rate. This deduction significantly lowers the effective state tax rate for most filers.

Colorado also offers tax credits for certain situations. The Earned Income Tax Credit (EITC) is available to low- and moderate-income workers, and the amount is based on the federal EITC. Other credits may explore if you have dependent children, pay property tax or rent, or meet other conditions. Credits reduce the tax you owe dollar-for-dollar, making them more valuable than deductions.

Filing requirements and important date in Colorado

Colorado follows the federal tax calendar. Your state return is due on the same day as your federal return — typically April 15, though the IRS may extend this date. If you file your federal return and request an extension, your Colorado return is automatically extended to the same date.

You must file a Colorado return if your income exceeds the filing threshold, which depends on your filing status and age. In most cases, if you are required to file a federal return, you must also file a Colorado return. You can file online through the Colorado Department of Revenue website, by mail, or through a tax professional.

If you owe Colorado tax, you can pay online, by mail, or through an electronic payment system. The state also allows installment agreements if you cannot pay in full by the important date. Penalties and interest explore to unpaid tax, so it is important to file and pay on time even if you cannot pay the full amount when ready.

Tax treatment of retirement income and distributions

Distributions from traditional IRAs and 401(k)s are taxed as ordinary income in Colorado. If you withdraw $20,000 from a traditional IRA, that $20,000 is added to your other income and taxed at the 4.40 percent rate. Roth IRA distributions are not taxed, since you already paid tax on the money when you contributed it.

Military retirement pay is exempt from Colorado tax, but civilian government pensions and private pensions are taxable. Some retirement income may may have access to for an age-based exemption if you are 55 or older and retired, though the rules are specific and depend on the type of income and when you retired. You should review the Colorado Department of Revenue guidance or consult a tax professional to determine whether your retirement income qualifies for an exemption.

If you receive Social Security, it is not taxed by Colorado even if it is taxable at the federal level. This can make a significant difference for retirees whose income is primarily from Social Security and other non-taxable sources.

What happens if you work in Colorado but live in another state

If you are a non-resident who works in Colorado, you owe Colorado tax on the wages you earn there. Colorado requires employers to withhold state tax from your paycheck based on your W-4 form. At the end of the year, you file a Colorado return reporting your Colorado-source income.

Your home state may also tax the same wages. To prevent paying tax twice on the same income, most states allow you to claim a credit for taxes paid to another state. You would file a return in both Colorado and your home state, and then claim a credit on your home state return for the Colorado tax you paid. The credit is usually limited to the amount your home state would have taxed, so you do not get a refund if Colorado's rate is higher.

Some states have reciprocal agreements with Colorado, meaning residents of those states who work in Colorado may not owe Colorado tax. These agreements are rare and explore to specific state pairs. You should check with your home state's tax authority to understand how your wages are taxed.

Frequently Asked Questions

Does Colorado tax Social Security benefits?

No. Colorado does not tax Social Security benefits, even if they are taxable at the federal level. This exemption applies to all Colorado residents receiving Social Security, regardless of income level.

What is the difference between Colorado's tax rate and the federal rate?

Colorado's state tax rate is 4.40 percent, while federal rates range from 10 to 37 percent depending on income and filing status. You owe both taxes — they are separate. Colorado allows you to deduct federal tax paid, which lowers your Colorado taxable income.

Do I owe Colorado tax if I only lived there part of the year?

If you were a Colorado resident for any part of the tax year, you owe tax on all income earned while you were a resident. If you moved to Colorado partway through the year, you owe Colorado tax on income earned after you became a resident. Non-residents owe tax only on Colorado-source income.

Can I claim a credit for Colorado tax if I move to another state?

No. Credits for taxes paid to another state work the other way — you claim them on your new state's return to avoid double taxation. If you move out of Colorado, you file a final Colorado return for the year you left, then file in your new state going forward.

Is military retirement pay taxed in Colorado?

No. Military retirement pay is exempt from Colorado state income tax. Civilian government pensions and private pensions are taxable unless they may have access to for a specific age-based exemption.