Colorado — Corporate Income / Franchise Tax

Colorado imposes a corporate income tax on each domestic C corporation, foreign C corporation, and combined group doing business in Colorado. The tax applies annually to the net income derived from sources within Colorado. All C corporations doing business in Colorado are required to file a Colorado corporate income tax return (Form DR 0112) with the Colorado Department of Revenue.

S corporations are not subject to Colorado corporate income tax; income from S corporations passes through to shareholders. Nonprofit corporations that file federal Form 990 and are exempt from filing a federal income tax return are also exempt from filing a Colorado income tax return. However, if a nonprofit has income from nonexempt functions subject to federal income tax (unrelated business taxable income), that income is subject to Colorado income tax and a return must be filed. Insurance companies subject to Colorado's insurance premium tax are exempt from Colorado income tax.

Source: Colorado Corporate Income Tax Guide | Corporate Income Tax Overview, Colorado General Assembly

Colorado imposes a flat corporate income tax rate of 4.4% on the Colorado net income of C corporations doing business in the state for income tax years commencing on or after January 1, 2022. This rate is codified in C.R.S. § 39-22-301(1)(d)(I)(K). The tax applies to net income derived from sources within Colorado, which includes income from tangible or intangible property located in the state and income from any activities carried on in Colorado.

The 4.4% rate may be temporarily reduced to 4.25% for certain tax years when excess state revenues trigger TABOR refund requirements under C.R.S. § 39-22-627. For tax year 2024, the rate was temporarily reduced to 4.25%.

Source: Corporate Income Tax Guide, Colorado Department of Revenue | Corporate Income Tax, Colorado General Assembly

Colorado follows the federal classification of partnerships and limited liability companies for income tax purposes and generally does not impose entity-level income tax on these pass-through entities. Instead, the partners or members are taxed on their distributive or pro rata shares of the entity's income, regardless of whether distributions are actually made.

General pass-through treatment: partners and members taxed, not the entity

Colorado statute provides that partners of a partnership—not the partnership entity itself—are subject to Colorado income tax. This is codified in Part 2 of Article 22 of Title 39, which covers "Partners and Partnerships." The structure mirrors the federal income tax treatment of partnerships under Subchapter K of the Internal Revenue Code.

Any group, organization, or business entity that is treated as a partnership for federal income tax purposes is treated as a partnership for Colorado income tax purposes, including any limited liability company classified as a partnership for federal income tax purposes. This conformity rule means that single-member LLCs disregarded for federal tax purposes are also disregarded for Colorado purposes, and multi-member LLCs treated as partnerships federally are treated as partnerships in Colorado.

An LLC classified as a partnership under the federal check-the-box regulations is not subject to Colorado corporate income tax at the entity level. Colorado defines "corporation" for corporate income tax purposes by reference to the federal definition and excludes entities classified as partnerships or S corporations under the Internal Revenue Code.

Publicly traded partnerships taxed as corporations under IRC § 7704

Colorado does not have a separate statutory provision specifically addressing publicly traded partnerships (PTPs). The Colorado Department of Revenue Corporate Income Tax Guide states that Colorado corporate income tax applies to "each domestic C corporation, foreign C corporation, and combined group doing business in Colorado" and that the tax "applies to all C corporations doing business in Colorado."

Because Colorado conforms to the federal definition of "corporation" and bases its corporate income tax on federal taxable income as the starting point, a publicly traded partnership that is classified as a corporation for federal income tax purposes under IRC § 7704(a)—because it does not qualify for the passive income exception under IRC § 7704(c)—is treated as a C corporation for Colorado purposes and is therefore subject to Colorado corporate income tax. Conversely, a PTP that qualifies for the IRC § 7704(c) exception and remains a partnership for federal purposes remains a pass-through entity for Colorado purposes and is not subject to entity-level Colorado income tax.

The Colorado Department of Revenue has not published guidance that separately addresses the treatment of publicly traded partnerships classified as corporations under IRC § 7704. Practitioners should confirm the entity's federal classification before determining Colorado filing obligations.

Optional entity-level taxation election: SALT Parity Act

For income tax years commencing on or after January 1, 2018, partnerships and S corporations may annually elect to be subject to Colorado income tax at the entity level under the SALT Parity Act, codified at C.R.S. §§ 39-22-340 to 39-22-347 and enacted by H.B. 21-1327 (amended by S.B. 22-124). This election was enacted to allow partners and shareholders to claim a federal deduction for state income taxes paid at the entity level, thereby avoiding the $10,000 federal cap on individual state and local tax deductions imposed by the Tax Cuts and Jobs Act of 2017. The election is available only in tax years when the federal IRC § 164 limitation on individual deductions for state and local taxes is in effect.

C.R.S. § 39-22-343 permits a partnership or S corporation to make the election annually on its Colorado Partnership and S Corporation Income Tax Return (Form DR 0106). For tax years commencing on or after January 1, 2022, the entity makes the election by checking the applicable box on Form DR 0106. The election is binding on all partners and shareholders for that tax year, except that the election does not apply to any partner that is a C corporation that is unitary with the partnership.

Under C.R.S. § 39-22-344, an electing partnership or S corporation is subject to Colorado income tax computed on the sum of (a) each resident partner's or shareholder's distributive or pro rata share of the entity's income (whether or not attributable to Colorado), and (b) each nonresident partner's or shareholder's distributive or pro rata share of the entity's income attributable to Colorado. Partners and shareholders in an electing pass-through entity are entitled to a credit under C.R.S. § 39-22-347 for their share of the entity-level tax paid, which offsets their individual Colorado income tax liability attributable to the pass-through entity's income.

The SALT Parity Act election is optional, not mandatory. Partnerships and S corporations that do not make the election continue to be treated as pass-through entities not subject to entity-level Colorado income tax, with their partners and shareholders reporting and paying Colorado income tax on their distributive shares.

Information reporting and withholding obligations

Even though partnerships and S corporations are generally not subject to entity-level income tax (absent a SALT Parity Act election), they must file an annual Colorado Partnership and S Corporation Income Tax Return (Form DR 0106) if they are doing business in Colorado or have Colorado-source income. The entity must also prepare and file Colorado K-1 forms (DR 0106K) for each partner or shareholder, reporting each member's distributive share of income, deductions, modifications, and credits.

For partnerships with nonresident partners, C.R.S. § 39-22-601(5) generally requires the partnership to either (a) file a nonresident agreement (Form DR 0107) under which the nonresident partner agrees to file a Colorado return and pay tax, or (b) pay Colorado income tax on behalf of the nonresident partner. C.R.S. § 39-22-601(5)(e), as amended by S.B. 22-124, provides that this withholding requirement does not apply to a partnership that makes the SALT Parity Act election under C.R.S. § 39-22-343.

Source: DR 0106 Partnership and S Corporation Income Tax Return, Colorado Department of Revenue | Income Tax Topics: SALT Parity Act, Colorado Department of Revenue | Corporate Income Tax Guide, Colorado Department of Revenue | H.B. 21-1327, Colorado General Assembly

A foreign C corporation has substantial nexus with Colorado for corporate income tax purposes if it exceeds any one of the following factor-presence thresholds during the tax year: $50,000 of property (average value of real and tangible personal property owned or rented in Colorado), $50,000 of payroll (compensation paid in Colorado), $500,000 of sales (gross receipts sourced to Colorado), or 25% of its total property, payroll, or sales in Colorado. Corporations organized or commercially domiciled in Colorado automatically have substantial nexus. A corporation is doing business in Colorado when it has substantial nexus and its activities exceed the protections of Public Law 86-272, which protects only solicitation of orders for sales of tangible personal property approved and shipped from outside Colorado.

Source: Corporate Income Tax Guide, Colorado Department of Revenue

Colorado uses a single-factor apportionment formula based on receipts for tax years beginning on or after January 1, 2019. Under C.R.S. § 39-22-303.6(4)(a), a multi-state corporation apportions its business income to Colorado by multiplying that income by a fraction: the numerator is receipts sourced to Colorado, and the denominator is receipts everywhere. Receipts from sales of tangible personal property are sourced to Colorado if the property is delivered or shipped to a purchaser in Colorado. All other receipts are sourced to Colorado if the taxpayer's market for the sale is in Colorado; for services, this means the extent the service is delivered to a Colorado location.

Source: C.R.S. § 39-22-303.6, Colorado Department of Revenue

Colorado C corporation income tax returns are due on the fifteenth day of the fifth month following the close of the taxable year. For calendar-year filers, this means the return is due May 15. This deadline applies to tax years beginning on or after January 1, 2024. An automatic six-month extension is available, extending the filing deadline to the fifteenth day of the eleventh month (November 15 for calendar-year filers), though at least 90% of the tax liability must be paid by the original due date to avoid penalties.

Source: Colorado Taxes & Fees Due Date Guide, Colorado Department of Revenue | DR 0158-C Extension Form, Colorado Department of Revenue

Colorado requires affiliated C corporations that meet common ownership and unitary business tests to file a combined report. The requirements changed substantially for tax years beginning on or after January 1, 2026, when Colorado replaced its six-tests-of-unity standard with the Multistate Tax Commission (MTC) model unitary business rule.

Common ownership requirement

Under C.R.S. § 39-22-303(8)(b)(I), all members of an affiliated group of C corporations that are members of a unitary business must file a combined report as a combined group. The common ownership prong requires that at least 50% of the stock of each corporation in the group be owned by another includible corporation and that the common parent corporation of the group own more than 50% of the stock of at least one other includible corporation. This common-ownership test applies for both pre-2026 and post-2025 tax years.

Unitary business test — tax years beginning before January 1, 2026

For tax years beginning before January 1, 2026, Colorado applies a six-tests-of-unity standard codified in C.R.S. § 39-22-303(11). An affiliated C corporation is includible in a combined report only if at least three of the following six facts have been in existence in the current tax year and the two preceding tax years: (1) sales or leases by one affiliated C corporation to another affiliated C corporation; (2) advertising done by one affiliated C corporation on behalf of another; (3) officers or directors of one affiliated C corporation are also officers or directors of another affiliated C corporation; (4) manufacturing, selling, or distribution facilities used jointly by two or more affiliated C corporations; (5) centralized accounting, legal, or personnel functions; and (6) common executive force. This six-test regime is unique to Colorado and has been characterized by the Colorado General Assembly as "arbitrary and difficult for taxpayers and the Colorado Department of Revenue to apply."

Unitary business test — tax years beginning on or after January 1, 2026

For tax years beginning on or after January 1, 2026, Colorado adopted the MTC model unitary business standard pursuant to H.B. 24-1134. Under C.R.S. § 39-22-303(8)(b)(I) as amended, members of an affiliated group that are engaged in a unitary business must be included in the combined group. The statute defines "unitary business" by reference to functional integration, centralized management, and economies of scale, following the MTC model. This change eliminates the three-of-six-tests requirement and the two-preceding-tax-years continuity requirement, which means corporations may be includible in the combined group in their first year of affiliation if they are unitary under the new standard.

Domestic holding companies and de minimis property/payroll exception

A C corporation formed under the laws of any state or the United States that has less than $100,000 of combined property and payroll is deemed to satisfy the tests of unity and must be included in a combined report, regardless of whether it meets the six tests (pre-2026) or the unitary business standard (post-2025). C.R.S. § 39-22-303(11)(f) provides that any such domestic C corporation "with de minimis or no property and payroll, as determined by factoring pursuant to section 24-60-1301," satisfies the unity requirements.

Section 24-60-1301 is Colorado's enactment of the Multistate Tax Compact (MTC). The Colorado Department of Revenue regulation 1 CCR 201-2, Rule 39-22-303(11)(f), clarifies that "de minimis" means less than $100,000 of property and payroll, combined, and that "property and payroll is determined by factoring pursuant to section 24-60-1301." The regulation further explains that "section 24-60-1301, C.R.S., establishes the criteria for valuing the amounts of property and payroll counting toward the $100,000 de minimis threshold." The MTC Article IV property and payroll factor definitions govern the measurement: property includes the average value of real and tangible personal property owned or rented, and payroll includes total compensation paid in the regular course of business.

This rule was enacted in 2019 via S.B. 233 in response to court decisions in Agilent Technologies, Inc. v. Brohl and similar cases, which held that domestic holding companies with no property or payroll could not be included in combined groups under the prior version of the statute.

Apportionment within a combined group (Finnigan rule)

For tax years beginning on or after January 1, 2022, the combined group apportionment factor numerator includes amounts sourced to Colorado from any member of the combined group, regardless of whether the member generating the Colorado receipts has nexus in Colorado. This is the Finnigan rule, codified at C.R.S. § 39-22-303(11)(c)(II)(B). Intercompany transactions among affiliated C corporations are eliminated from both the numerator and denominator of the apportionment calculation under C.R.S. § 39-22-303(11)(c)(I).

Consolidated vs. combined returns

Colorado distinguishes between combined reporting (mandatory for unitary groups meeting the tests above) and consolidated reporting (elective under C.R.S. § 39-22-303(12) for affiliated groups under IRC § 1504 that are doing business in Colorado). A taxpayer may file a combined return, a consolidated return, or a combined-consolidated return depending on its facts. Only C corporations doing business in Colorado may be included in a consolidated return.

Source: C.R.S. § 39-22-303 | 1 CCR 201-2, Rule 39-22-303(11)(f) | Corporate Income Tax Guide, Colorado Department of Revenue

Colorado C corporations calculate their Colorado net income by starting with federal taxable income and then applying Colorado-specific additions and subtractions. Under C.R.S. § 39-22-304(1)(a), the net income of a C corporation means the corporation's federal taxable income, as defined in the Internal Revenue Code, for the taxable year, with the modifications specified in the statute. Federal taxable income is reported on line 30 of federal Form 1120 (or line 11 of Form 990-T for unrelated business taxable income).

Colorado conforms to the Internal Revenue Code on a rolling basis, meaning that most federal deductions and adjustments automatically apply for Colorado purposes without separate modification. However, Colorado law requires specific additions to and subtractions from federal taxable income to arrive at Colorado net income.

Required additions to federal taxable income

C.R.S. § 39-22-304(2) mandates the following additions to federal taxable income:

• Foreign income taxes — Any income, war profits, or excess profits taxes paid or accrued to any foreign country or U.S. possession that were deducted on the federal return must be added back (C.R.S. § 39-22-304(2)(a)).

• Out-of-state municipal bond interest — Interest income (net of amortized premium) on obligations of any state or political subdivision thereof, other than Colorado or its political subdivisions (for bonds issued on or after May 1, 1980), must be added back. Interest on Colorado obligations issued on or after May 1, 1980 is exempt from Colorado income tax. For bonds issued before May 1, 1980, specific exemption language governs (C.R.S. § 39-22-304(2)(b)).

• Federal net operating loss deduction — The federal net operating loss deduction claimed on the federal return must be added back because Colorado has its own separate net operating loss regime (C.R.S. § 39-22-304(2)(c)).

• State income taxes — "Income taxes imposed by this state to the extent deducted in determining federal taxable income, except the tax imposed by article 29 of this title" must be added back (C.R.S. § 39-22-304(2)(d)). This prevents a corporation from deducting Colorado income taxes at the state level.

• Discriminatory club expenses — Any expenses incurred with respect to expenditures at or payments to clubs licensed under C.R.S. § 44-3-418 that have a policy restricting membership on the basis of sex, sexual orientation, gender identity, gender expression, marital status, race, creed, religion, color, ancestry, or national origin must be added back (C.R.S. § 39-22-304(2)(e)).

• Gross conservation easement credit — The full value of certain gross conservation easement credits is added back, subject to specific timing and limitation rules (C.R.S. § 39-22-304(2)(f)).

• Prohibited labor services expenses — An amount equal to a business expense for labor services deducted under IRC § 162(a)(1) but prohibited from being claimed as a deductible business expense under C.R.S. § 39-22-529 must be added back (C.R.S. § 39-22-304(2)(h)).

• CARES Act business interest limitation adjustment — For income tax years ending on and after enactment of the March 2020 CARES Act but before January 1, 2021, and for income tax years beginning on and after enactment of the CARES Act but before January 1, 2021, an amount equal to the excess business interest limitation under IRC § 163(j) without regard to amendments made by section 2306 of the CARES Act (C.R.S. § 39-22-304(2)(i)).

• Food and beverage expense addback — For income tax years commencing on or after January 1, 2022, but before January 1, 2023, an amount equal to a federal deduction claimed for food and beverage expense that exceeds 50% of the amount of the expense and that was allowed under IRC § 274(n)(2)(D). This subsection is repealed effective December 31, 2030 (C.R.S. § 39-22-304(2)(j)).

• GILTI foreign-derived deduction (FDDEI) — For tax years beginning on or after January 1, 2026, any deduction claimed on the federal return under IRC § 250 for foreign-derived deduction eligible income must be added back (C.R.S. § 39-22-304(2)(q)).

No related-party expense or interest addback

Colorado does not have a related-party expense addback statute. Unlike states such as New York, New Jersey, or Massachusetts, Colorado law does not require taxpayers to add back intangible expenses or interest paid to related parties. Payments to related parties are deductible for Colorado corporate income tax purposes to the same extent they are deductible for federal income tax purposes, subject to general federal transfer pricing principles.

Permitted subtractions from federal taxable income

C.R.S. § 39-22-304(3) permits the following subtractions from federal taxable income:

• U.S. government obligations interest — Interest income on obligations of the United States and its possessions to the extent included in federal taxable income (C.R.S. § 39-22-304(3)(a)).

• Disposition of assets with higher Colorado basis — The portion of any gain from the sale or other disposition of property having a higher adjusted basis for Colorado income tax purposes than for federal purposes. This applies primarily to assets purchased before January 1, 1965, when Colorado transitioned to using federal taxable income as the starting point (C.R.S. § 39-22-304(3)(c)).

• Pollution control facilities amortization — Accelerated amortization of certified pollution control facilities (C.R.S. § 39-22-304(3)(d)).

• Charitable contributions of land — Certain charitable contributions of real property (C.R.S. § 39-22-304(3)(e)).

• Carryforward of disallowed federal deductions — Under specified conditions, taxpayers may subtract amounts of federal deductions disallowed by recent federal tax law changes, carried forward over time (C.R.S. § 39-22-304(3)(f)).

• Colorado net operating loss deduction — A Colorado-specific net operating loss deduction calculated separately from the federal NOL (C.R.S. § 39-22-304(3)(g) and C.R.S. § 39-22-504).

• Dividend income — Certain dividend income received by a C corporation (C.R.S. § 39-22-304(3)(h)).

• CARES Act subtraction — A limited subtraction for retroactive effects of the federal CARES Act on Colorado taxable income for specified tax years, subject to annual caps and carryforward provisions (C.R.S. § 39-22-304(3)(i)).

• IRC § 78 gross-up dividends — Amounts treated as dividends received under IRC § 78 (the gross-up for deemed-paid foreign tax credits) are subtracted (C.R.S. § 39-22-304(3)(j)).

• Foreign source income exclusion — Under C.R.S. § 39-22-303(10), a C corporation may exclude a portion of its foreign source income when it claims a federal foreign tax credit. The exclusion is calculated by formula and applies both to net income and to the apportionment fraction denominator.

After applying these additions and subtractions to federal taxable income, multi-state corporations apportion the resulting business income to Colorado under the single-factor receipts apportionment method (C.R.S. § 39-22-303.6(4)(a)). The apportioned Colorado net income is then multiplied by the applicable tax rate to determine Colorado income tax.

Source: C.R.S. § 39-22-304, Colorado General Assembly | C.R.S. § 39-22-303, Colorado General Assembly | C.R.S. § 39-22-303.6, Colorado General Assembly | Corporate Income Tax Guide, Colorado Department of Revenue

Colorado C corporations must remit quarterly estimated income tax payments if the corporation can reasonably expect its net Colorado tax liability to exceed $5,000 for the year. No penalty is due if the corporation's Colorado tax liability for the year is less than $5,000.

Quarterly payment due dates

Estimated tax payments are due in four installments on the 15th day of the 4th, 6th, 9th, and 12th month of the corporation's tax year. For calendar-year C corporations, these dates are April 15, June 15, September 15, and December 15. Fiscal-year filers adjust these dates accordingly based on their tax year. If a due date falls on a Saturday, Sunday, or state holiday, the payment is due on the next business day.

Estimated tax payments must be submitted in the same manner (separate, consolidated, or combined) and using the same account number that the corporation expects to use when filing the Colorado corporation income tax return (Form DR 0112).

Calculation of net Colorado tax liability

For purposes of the estimated tax computation, the Colorado tax liability is defined as the total amount of Colorado tax plus the recapture of prior year credits, minus all income tax credits other than withholding credits and estimated tax credits. This definition is codified in Colorado Department of Revenue regulation 1 CCR 201-2, Rule 39-22-606.

Required annual payment and safe harbor provisions

The required annual amount to be paid is the lesser of:

• 70% of the corporation's net Colorado tax liability for the current tax year, or
• 100% of the corporation's net Colorado tax liability for the preceding tax year (if the corporation filed a Colorado return for the prior year covering a full twelve months).

Each quarterly installment payment is generally 25% of the required annual payment. If three payments are required, each installment must be 33% of the required annual payment. If two payments are required, each installment must be 50% of the required annual payment. If only one payment is required, the payment must be 100% of the required annual payment.

These safe harbor thresholds are established in C.R.S. § 39-22-606(5)(b), which provides that the required annual payment means "the lesser of: Seventy percent of the taxpayer's actual Colorado tax liability shown on the return for the taxable year or, if no return is filed, seventy percent of the tax for such year; or One hundred percent of the taxpayer's actual Colorado tax liability shown on the return of the corporation for the preceding taxable year." The 100% prior-year safe harbor does not apply if the preceding taxable year was not a twelve-month period or if the taxpayer did not file a Colorado return for that year.

Large corporation exception

Corporations defined under IRC § 6655 as "large corporations" can base their first quarter estimated tax payment on 25% of the previous year's tax liability. However, future payments (second, third, and fourth quarters) must be based on the actual tax liability for the current tax year, and any underpayment occurring in the first quarter as a result of using the prior-year estimate must be repaid with the second quarterly payment. C.R.S. § 39-22-606(5)(c)(I) provides that "the first required installment … for any taxable year may be based on twenty-five percent of the taxpayer's actual Colorado tax liability shown on the return of the corporation for the preceding year" and that "[a]ny reduction in the first installment … shall be recaptured by increasing the amount of the next required installment."

Annualized income installment method

Corporations that do not receive income evenly during the year may elect to use the annualized income installment method to compute their estimated tax payments if they elected annualized installments or adjusted seasonal installments for payment of their federal income tax. Under this method, the required installment payment on each due date is the Colorado tax liability computed by annualizing the income received during the months of the tax year ending on the last day of the month before the due date for the installment payment, minus the total of any earlier installment payments made for the tax year.

If tax is computed by apportioning income, apportionment factors must be computed for each quarter in order to use the annualized income installment method. Use of estimated or prior-year apportionment factors is not accepted. A schedule and explanation of the allocation methodology must be made available to the Colorado Department of Revenue upon request when using the annualized method. These requirements are set forth in 1 CCR 201-2, Rule 39-22-606.

Underpayment penalty

The estimated tax penalty for C corporations is assessed if the required estimated tax payments are not paid in a timely manner. The penalty is calculated as the appropriate Colorado income tax interest rate multiplied by the underpayment for each quarter multiplied by the underpayment period. No penalty is due if the Colorado tax liability is less than $5,000. If a short taxable year is involved, the income must be placed on an annual basis, in which case the $5,000 requirement for filing estimated tax payments applies in the same manner as for a full-year taxpayer. C.R.S. § 39-22-606(3)(a) provides that "in the case of any underpayment of estimated tax by a corporation, there shall be added to the tax … for the taxable year an amount determined by applying the rate of interest established under section 39-21-110.5 to the amount of the underpayment for the period of the underpayment."

Payment crediting

Payments are credited against the earliest quarterly installment due for the tax year, regardless of when the payment is received.

Source: C.R.S. § 39-22-606, Colorado General Assembly | 1 CCR 201-2, Rule 39-22-606, Colorado Secretary of State | Business Income Tax Estimated Payments, Colorado Department of Revenue | DR 0112EP Corporate Estimated Income Tax Payment Form, Colorado Department of Revenue

Colorado generally exempts insurance companies from corporate income tax if they are subject to the state's insurance premium tax. However, "disqualified insurance companies" are an exception to this rule: they are excluded from the premium tax exemption and therefore remain subject to Colorado corporate income tax.

Definition of disqualified insurance company

A "disqualified insurance company" is a company licensed as a captive insurance company under Colorado law or the laws of another jurisdiction with gross receipts for the taxable year that consist of fifty percent or less of premiums from arrangements that constitute insurance for federal income tax purposes. This definition is codified at C.R.S. § 10-1-102(6.5).

The defining characteristic is the premium composition test: if 50% or less of the company's gross receipts come from arrangements that qualify as insurance for federal income tax purposes, the company is disqualified. This test targets captive insurance arrangements that may not constitute true insurance under federal tax law—often those involving related-party transactions or arrangements that fail to meet federal insurance standards under the Internal Revenue Code, lack sufficient risk distribution or risk shifting, or otherwise do not meet federal insurance requirements.

Exclusion from premium tax and resulting income tax obligation

Disqualified insurance companies are expressly excluded from the insurance premium tax regime. C.R.S. § 10-3-209(1)(a) and § 10-6-128(1) (for captive insurers) both state that all insurance companies or captive insurance companies doing business in Colorado, "except a disqualified insurance company," shall pay the premium tax to the Division of Insurance.

Because disqualified insurance companies are excluded from the premium tax, they do not qualify for the general exemption from corporate income tax afforded to insurers paying the premium tax. Consequently, a disqualified insurance company that is organized as a C corporation and meets the nexus and doing-business tests is subject to Colorado corporate income tax under the standard rules applicable to all C corporations doing business in the state.

Effective date and purpose

The disqualified insurance company carve-out was enacted by H.B. 21-1311, effective June 23, 2021. The Colorado General Assembly's summary of the bill explains that sections 10 through 13 of the act "address the avoidance of income tax by certain captive insurance companies." The legislative intent was to close a perceived tax avoidance opportunity whereby captive insurance companies—particularly those with premium arrangements that do not constitute insurance for federal tax purposes—could avoid both premium tax (by not having sufficient qualifying premiums) and corporate income tax (by claiming insurer status).

Interaction with combined reporting

A disqualified insurance company that is subject to Colorado corporate income tax and is part of an affiliated group meeting the common ownership and unitary business tests under C.R.S. § 39-22-303 must be included in the combined group's combined return under the rules set forth in that statute. The company's income, apportionment factors, and intercompany eliminations are treated the same as any other C corporation member of the combined group. The insurance-specific premium tax treatment does not affect combined reporting obligations once the company is classified as subject to corporate income tax.

Source: C.R.S. § 10-1-102, Colorado General Assembly | C.R.S. § 10-3-209, Colorado General Assembly | H.B. 21-1311, Colorado General Assembly

Colorado C corporations calculate their Colorado net income by starting with federal taxable income and applying Colorado-specific additions and subtractions mandated by statute. C.R.S. § 39-22-304(1)(a) provides that net income means federal taxable income "with the modifications specified in this section." The addition modifications required under C.R.S. § 39-22-304(2) either subject to Colorado taxation certain types of income exempt from federal tax or eliminate deductions allowed federally but not at the state level.

State income tax addback

C.R.S. § 39-22-304(2)(d) requires Colorado C corporations to add back to federal taxable income any "income taxes imposed by this state to the extent deducted in determining federal taxable income, except the tax imposed by article 29 of this title." This addback prevents corporations from claiming a Colorado-level deduction for Colorado income taxes paid or accrued. The exception for article 29 refers to the severance tax on oil and gas production, which may be deducted for Colorado income tax purposes if deducted federally. This addback applies to all tax years.

Foreign income taxes

C.R.S. § 39-22-304(2)(a) requires an addback of any income, war profits, or excess profits taxes paid or accrued to any foreign country or U.S. possession that were deducted on the federal income tax return. This addback applies only if the taxpayer elected to deduct foreign taxes on the federal return; if the foreign taxes were claimed as a federal tax credit under IRC § 901, no addback is required because the taxes were not deducted from federal taxable income. This provision applies to all tax years.

Out-of-state municipal bond interest

Under C.R.S. § 39-22-304(2)(b), interest income (net of amortized premium) on obligations of any state or political subdivision other than Colorado or its political subdivisions must be added back. This addback applies to bonds issued on or after May 1, 1980. Interest on Colorado municipal bonds issued on or after May 1, 1980 is exempt from Colorado income tax and therefore requires no addback. For bonds issued before May 1, 1980, specific statutory exemption language in the authorizing law governs. The amount of the addback is reduced by the amount of deductions required by the Internal Revenue Code to be allocated to such interest income.

Federal net operating loss deduction

C.R.S. § 39-22-304(2)(c) requires an addback of the federal net operating loss deduction claimed on the federal return because Colorado has its own separate net operating loss regime codified at C.R.S. § 39-22-504. After adding back the federal NOL deduction, a C corporation may claim a Colorado-specific NOL deduction as a subtraction from federal taxable income under C.R.S. § 39-22-304(3)(g), computed under Colorado's separate rules.

Business meals addback (tax years 2024–2030)

For income tax years commencing on or after January 1, 2024, but before January 1, 2031, C.R.S. § 39-22-304(2)(k) requires C corporations to add back the full amount of any federal deduction claimed for business meals pursuant to IRC § 274(k). This subsection is repealed effective December 31, 2035. The addback equals the entire amount deducted federally under IRC § 274(k).

For tax year 2022 only (tax years commencing on or after January 1, 2022, but before January 1, 2023), a different addback applied under former C.R.S. § 39-22-304(2)(j) (repealed effective December 31, 2030): corporations were required to add back food and beverage expenses deducted in excess of 50% of the expense, reflecting the temporary 100% federal deduction allowed by IRC § 274(n)(2)(D) for restaurant-provided food during the COVID-19 pandemic.

GILTI foreign-derived deduction (FDDEI) addback (tax years beginning 2026 and after)

For tax years beginning on or after January 1, 2026, C.R.S. § 39-22-304(2)(q) requires an addback of any deduction claimed on the federal return under IRC § 250 for foreign-derived deduction eligible income (FDDEI). The full amount of the federal IRC § 250 deduction attributable to FDDEI must be added back to federal taxable income for Colorado purposes.

Discriminatory club expenses

C.R.S. § 39-22-304(2)(e) requires an addback of any expenses incurred by a taxpayer with respect to expenditures made at, or payments made to, a club licensed under C.R.S. § 44-3-418 (now § 44-3-418) that has a policy restricting membership on the basis of sex, sexual orientation, gender identity, gender expression, marital status, race, creed, religion, color, ancestry, or national origin. Such clubs are required to provide on each receipt a printed statement that the expenditures are nondeductible for state income tax purposes.

Gross conservation easement credit addback

C.R.S. § 39-22-304(2)(f) requires an addback of the full value of certain gross conservation easement credits, subject to specific timing and limitation rules. If a charitable deduction is claimed on the federal income tax return for any donation upon which a gross conservation easement credit is also claimed, the amount deducted from federal taxable income must be added back to Colorado taxable income. The aggregate addition required for all tax years with respect to any single gross conservation easement donation is limited to the contribution amount upon which the gross conservation easement credit claim is based. Department regulation 1 CCR 201-2, Rule 39-22-304(2)(f), provides implementation detail.

Prohibited labor services expenses

C.R.S. § 39-22-304(2)(h) requires an addback of any amount equal to a business expense for labor services deducted under IRC § 162(a)(1) but prohibited from being claimed as a deductible business expense under C.R.S. § 39-22-529. C.R.S. § 39-22-529 disallows deductions for wages or remuneration paid to an unauthorized alien for the physical performance of services in Colorado. This addback applies to all tax years.

CARES Act business interest limitation adjustment (limited tax years)

For income tax years ending on and after the date of enactment of the March 2020 CARES Act but before January 1, 2021, and for income tax years beginning on and after the date of enactment of the CARES Act but before January 1, 2021, C.R.S. § 39-22-304(2)(i) requires an addback of an amount equal to the excess business interest deduction allowed under IRC § 163(j) without regard to amendments made by section 2306 of the CARES Act. This addback captures the additional federal deduction resulting from the CARES Act's temporary increase in the IRC § 163(j) limitation from 30% to 50% of adjusted taxable income. Colorado partially decoupled from this federal relief. A corresponding subtraction was later allowed under C.R.S. § 39-22-304(3)(i) for qualifying taxpayers in tax year 2021.

No related-party expense or interest addback

Colorado does not require C corporations to add back intangible expenses or interest paid to related parties. Colorado has no statutory provision analogous to the related-party addback regimes enacted in certain other states. Payments to related parties—including royalties, interest, management fees, and other intangible expenses—are deductible for Colorado corporate income tax purposes to the same extent they are deductible for federal income tax purposes, subject to general federal transfer pricing principles under IRC § 482. No Colorado statute or regulation requires an addback of such payments based solely on related-party status.

Source: C.R.S. § 39-22-304, Colorado General Assembly | C.R.S. § 39-22-504, Colorado General Assembly | C.R.S. § 39-22-529, Colorado General Assembly | 1 CCR 201-2, Rule 39-22-304(2)(f), Colorado Secretary of State | Corporate Income Tax Guide, Colorado Department of Revenue

Colorado allows C corporations to deduct net operating losses (NOLs) from Colorado taxable income under a separate state regime that differs from the federal NOL rules. Because Colorado requires taxpayers to add back the federal NOL deduction when computing Colorado net income, corporations must calculate and claim a Colorado-specific NOL deduction.

Computation of Colorado net operating loss

Under C.R.S. § 39-22-504(1)(a), a net operating loss deduction is allowed "in the same manner that it is allowed under the internal revenue code except as otherwise provided in this section." The Colorado NOL is computed using the same federal rules for determining what constitutes a net operating loss, but the amount is based on the portion of the federal NOL allocated to Colorado under the state's apportionment and allocation rules for the year the loss was sustained.

For multi-state corporations, the Colorado NOL equals the federal NOL multiplied by the Colorado apportionment percentage for the loss year. The Colorado NOL is further modified by Colorado-specific additions and subtractions required under C.R.S. § 39-22-304(2) and (3), such as the addback of state income taxes and the subtraction of U.S. government bond interest.

Carryforward periods — no carryback allowed

Colorado C corporations may not carry back NOLs to prior tax years, regardless of whether federal law allows carrybacks. C.R.S. § 39-22-504(3)(a) and (3)(b) expressly prohibit carrybacks for all corporate NOLs.

For NOLs generated in income tax years commencing before January 1, 2021, Colorado allows carryforward for the same number of years as allowed for a federal NOL. Because federal law enacted in 2017 (the Tax Cuts and Jobs Act) permits indefinite carryforward for federal NOLs arising in tax years beginning after December 31, 2017, Colorado NOLs arising in such years also carry forward indefinitely under the conformity rule in C.R.S. § 39-22-504(3)(a).

For NOLs of corporations generated in income tax years commencing on or after January 1, 2021, Colorado decoupled from the federal indefinite carryforward rule and instead allows a twenty-year carryforward period under C.R.S. § 39-22-504(3)(b), enacted by H.B. 20-1024 in June 2020.

Eighty percent limitation for post-2017 losses

For losses incurred after December 31, 2017, the eighty percent limitation set forth in IRC § 172(a)(2) applies to Colorado NOL deductions. Under C.R.S. § 39-22-504(1)(b), this 80% limitation applies "without regard to the amendments made in section 2303 of the March 2020 'Coronavirus Aid, Relief, and Economic Security Act.'" This means that even though the federal CARES Act temporarily suspended the 80% cap for certain federal tax years, Colorado did not adopt that suspension.

The 80% limitation restricts the annual Colorado NOL deduction to the lesser of (1) the available Colorado NOL carryforward, or (2) 80 percent of Colorado taxable income before the NOL deduction (for losses arising in tax years beginning after December 31, 2017). The limitation applies after deducting any Colorado NOL arising in a tax year beginning prior to January 1, 2018, which is not subject to the 80% cap.

Temporary $250,000 annual limitation (tax years 2011–2013)

For tax years commencing on or after January 1, 2011, but prior to January 1, 2014, Colorado imposed a temporary cap on the annual Colorado NOL deduction. Under C.R.S. § 39-22-504(6)(a), the maximum NOL deduction for those years was $250,000. Corporations affected by this limitation were allowed to carry forward the disallowed portion of the NOL for one additional year beyond the standard carryforward period, and the unused portion was increased by 3.25% annually under C.R.S. § 39-22-504(6)(b) and the corresponding Department of Revenue regulation. This limitation is no longer in effect for tax years beginning on or after January 1, 2014.

Ordering and allocation rules

Colorado NOLs must be carried forward to the tax year immediately following the year the loss was sustained, and losses must be applied in chronological order (oldest loss first). If a C corporation has available NOL carryforwards originating in multiple tax years, the corporation must first deduct the loss arising from the earliest tax year.

For combined or consolidated groups, the Colorado NOL is calculated with respect to only the C corporations included in the combined or consolidated return and is based on the federal NOL determined for that group. Intercompany eliminations and apportionment rules apply at the group level.

Interaction with federal NOL addback and subtraction

As noted in C.R.S. § 39-22-304(2)(c), C corporations must add back to federal taxable income the full amount of the federal NOL deduction claimed on the federal return. After making this addback and computing Colorado net income (including Colorado-specific modifications and apportionment), the taxpayer may then subtract the Colorado NOL deduction as a modification under C.R.S. § 39-22-304(3)(g). This ensures that Colorado NOLs are calculated and applied independently of federal NOLs.

Section 382 and other federal limitations

Federal limitations on NOL usage, including the IRC § 382 limitation on NOLs following an ownership change, apply for Colorado purposes. For purposes of applying the IRC § 382 limitation to Colorado NOLs, the limitation amount is apportioned to Colorado using the Colorado apportionment fraction of the loss corporation for the last full tax year prior to the ownership change. Similarly, other federal NOL limitation rules (such as the separate return limitation year rules for consolidated groups) generally apply to Colorado NOLs.

Source: C.R.S. § 39-22-504, Colorado General Assembly | H.B. 20-1024, Colorado General Assembly | H.B. 20-1420, Colorado General Assembly