Does Colorado Tax Capital Gains? Flat Rate, Subtractions, and Filing

Yes, Colorado does tax capital gains. The state applies its flat 4.40% income tax rate to capital gains the same way it taxes wages or interest, with no separate long-term rate and no graduated brackets. Because your Colorado return starts from federal taxable income, every gain already reported on your federal Schedule D flows straight through to the state calculation.¹

The Flat 4.40% Rate Applies to All Gains

Colorado has a single flat income tax rate, and since voters approved Proposition 121 in November 2022, that rate has been 4.40%. A dollar of capital gain is taxed at the same rate as a dollar of salary. The state does not distinguish between short-term and long-term holdings, and there is no preferential rate schedule for investment income.

That means the federal rate structure most investors are used to — 0%, 15%, or 20% on qualified long-term gains — has no state counterpart in Colorado. Any state-level relief comes through subtractions from taxable income, not through a lower rate.

How the Gain Gets Onto Your Colorado Return

Colorado’s income tax calculation begins with your federal taxable income, the figure on line 15 of IRS Form 1040.² Your net capital gains and losses are already baked into that number through Schedule D. You don’t recompute basis, holding periods, or the $3,000 annual cap on deducting net capital losses against ordinary income for state purposes. Federal capital loss carryovers carry over automatically as well.

From there, Colorado requires certain additions (including the addback of your federal standard or itemized deduction, the state income tax deduction, and the qualified business income deduction), then allows specific subtractions.³ The 4.40% rate is applied to the result.

The Agricultural Capital Gain Subtraction

Colorado offers one narrow subtraction that can reduce or eliminate state tax on qualifying capital gains. For tax years beginning on or after January 1, 2022, it applies only to gains from the sale of qualifying agricultural real property.⁴ Gains from stocks, other intangibles, and tangible personal property no longer qualify. If you sold a rental property, a small business, or a brokerage account, the subtraction is not available to you.

To claim it, all of the following must be true:

The real property was classified as agricultural land by the county assessor immediately before the sale.⁵
You acquired the property on or after May 9, 1994, but before June 4, 2009.
You owned the property for at least five uninterrupted years before the sale.⁶
The subtraction is capped at $100,000 of qualifying net gains per tax year.⁵

If the property is sold as part of an investment package, at least 75% of the real property in the package must carry the agricultural classification for the gain to qualify.⁵

Qualified Small Business Stock

Colorado uses rolling conformity with the Internal Revenue Code and starts its calculation from federal taxable income, so the federal Section 1202 exclusion for qualified small business stock (QSBS) flows through automatically. A gain fully excluded at the federal level never enters your federal taxable income and never appears on your Colorado return. Founders and early investors in qualifying C corporations get the full benefit of the federal exclusion at the state level without any separate Colorado election or form.

Nonresidents and Part-Year Residents

If you don’t live in Colorado all year, the state only taxes capital gains that are sourced to Colorado. Sourcing depends on the type of property:⁷

Gains from real property and tangible personal property located in Colorado are Colorado-source. A nonresident who sells Colorado real estate owes Colorado tax on the gain.
Gains from intangibles like stocks and bonds are Colorado-source only if the property was employed in a business carried on in Colorado. A nonresident selling stock from a personal brokerage account generally owes no Colorado tax.

Part-year residents and nonresidents complete Form DR 0104PN in addition to the standard DR 0104. The form calculates an apportionment percentage from Colorado-source income over total modified federal AGI, and the state tax is prorated by that percentage.⁸

Estimated Payments After a Large Gain

A significant capital gain can trigger a requirement to pay Colorado tax during the year rather than at filing. If your Colorado tax liability after withholding and credits will exceed $1,000 for the year, you generally must make quarterly estimated payments or face an underpayment penalty.⁹

To avoid the penalty, your payments plus withholding must meet the smallest of these safe harbors:

70% of your actual net Colorado tax liability for the current year.
100% of the prior year’s net Colorado tax liability, if your prior-year federal AGI was $150,000 or less ($75,000 if married filing separately).
110% of the prior year’s net Colorado tax liability, with no income cap.⁹

If last year’s income was modest and this year brings a one-time large gain, the prior-year safe harbor is usually the simplest way to stay out of penalty territory.

Late Payment Penalty and Interest

If you owe Colorado tax on a capital gain and miss the filing deadline, the state charges both a penalty and interest. The late filing or late payment penalty is the greater of $5 or 5% of the unpaid tax, plus an additional 0.5% for each month or partial month the balance stays outstanding, up to a combined maximum of 12%.¹⁰

Interest runs separately from the original due date until you pay. For the 2026 calendar year, the discounted rate is 8% if you pay before receiving a notice of deficiency or within 30 days of receiving one. Wait longer and the regular rate of 11% applies.¹¹

Keep your federal Schedule D, any 1099-B forms, and, if you claim the agricultural subtraction, documentation of the county’s agricultural classification. Colorado can audit up to four years from the filing date, and missing basis records are the fastest way to lose a subtraction you legitimately earned.

1
Colorado Department of Revenue. Individual Income Tax Guide
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Colorado Department of Revenue. Colorado Individual Income Tax Filing Guide
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Colorado Department of Revenue. 2025 Colorado Individual Income Tax Return
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Colorado Department of Revenue. Income Tax Topics – Colorado Capital Gain Subtraction
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Justia Law. Colorado Code 39-22-518 – Tax Modification for Net Capital Gains
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Colorado Department of Revenue. Income Tax Topics – Colorado Capital Gain Subtraction
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Colorado Department of Revenue. Income Tax Topics – Part-Year Residents and Nonresidents
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Colorado Department of Revenue. DR 0104PN – Part-Year Resident/Nonresident Calculation Schedule
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Legal Information Institute. Colorado Code 39-22-605 – Estimated Individual Income Tax
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Colorado Department of Revenue. Tax Topics – Penalties and Interest
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Colorado Department of Revenue. Tax Topics – Penalties and Interest