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Motor Fuel Tax 

Table of Contents

Background

Enacted in 1933, the gasoline tax is imposed on the sale of gasoline and its derivatives.1 The special fuels tax is imposed on the sale of diesel engine fuel and other alternative fuels. The tax is collected from the distributor of the fuel or terminal operator who acquires, sells, imports, or removes fuel from storage, but the tax is required to be paid only once on the same gasoline or special fuel. The tax is calculated on gross gallons acquired and is required to be remitted on all transfers from the previous month by the 26th calendar day of the month. Payments are made via electronic funds transfers to the executive director of the Department of Revenue.2 For filing instructions, visit the Department of Revenue website. Motor fuel tax revenue is subject to the spending and revenue limitations of TABOR.

Tax Rate

The gasoline tax was last increased in 1991 to a rate of 22¢ per gallon3. Gasoline is defined as “any flammable liquid used primarily as a fuel for the propulsion of motor vehicles, motor boats, or aircraft.”4 This includes conventional gasoline and several derivate blends, such as Gasohol or E10, which is a blend of gasoline and ethanol composed of 10 percent or less ethanol.

The special fuels tax is assessed at a rate of 20.5¢ per gallon.5  Special fuels include diesel fuel, kerosene, and ethanol blends of more than 10 percent ethanol, when used for the generation of power to propel a motor vehicle on highways.  Beginning in 2014, compressed natural gas (CNG), liquefied natural gas (LNG), and liquefied petroleum gas (LPG) became subject to tax at rates that phased in over time.  Beginning in 2019, these rates were fully phased in at 18.3¢ for CNG, 12¢ for LNG, and 13.5¢ for LPG.6

Beginning April 1, 2023, gasoline and special fuels are subject to additional road usage fees, and special fuels are subject to additional bridge and tunnel impact fees. Fee schedules phase in over time. Road usage fees are subject to TABOR, while bridge and tunnel impact fees are credited to a TABOR-exempt state enterprise. Beginning September 2023, distributors who import gasoline must pay the fuel impact reduction fee of 0.6¢ per gallon. Fuel sold in Colorado is also subject to the environmental response surcharge and perfluoroalkyl and polyfluoroalkyl substances (PFAS) fee. Because these charges are fees, not taxes, they are omitted from the visualization in this tax handbook.
 
Tax Exemptions

Inherently, the motor fuel tax applies only to fuel used for motor vehicles and therefore does not apply to gasoline or other special fuels used for residential power purposes. Other exemptions;7 to the motor fuel tax include:

  • fuel in a vehicle’s fuel tank. A person using a passenger car, bus, or truck is exempt from paying the fuel tax for the fuel brought into Colorado in the vehicle’s ordinary fuel tank, unless a person is operating a qualified motor vehicle pursuant to the International Fuel Tax Agreement (IFTA);
  • supplied at a residential home. Compressed natural gas used for motor vehicles is exempt from the tax if it is supplied at a residential home;
  • deliveries. Gasoline or special fuel that’s removed from a terminal exclusively for delivery to another state is exempt from the tax;
  • fuel used by government entities. Fuel purchased by government entities at any level—federal, state, or local—are exempt from the tax, as long as the fuel is exclusively used to perform government functions and activities; and
  • dyed diesel. Fuel dyed under EPA and IRS rules is generally prohibited from being used in any motor vehicles on public roads and is exempt from the tax. This includes fuel for mining activities, farm tractors and vehicles when such vehicles are on a farm or ranch, and vehicles or construction equipment operated within the construction project.
Distribution

Motor fuel revenue is deposited into the Highway Users Tax Fund (HUTF) and from there it is distributed to the state, counties, and cities based on a statutory formula.8 Motor fuel tax revenue is divided into two “pots” prior to allocation: the first 7¢ of the tax rate and everything else (above 7¢).  The first 7¢ is distributed 65 percent to the State Highway Fund, 26 percent to counties, and 9 percent to cities after off-the-top deductions occur. Off-the-top deductions fund the Ports of Entry under the Department of Revenue, the Colorado State Patrol, and the Department of Public Safety. Funds above 7¢ are distributed to the State Highway Fund, counties, and cities at proportions of 60 percent, 22 percent, and 18 percent, respectively.

Federal Taxes

The federal gasoline tax is assessed at 18.3¢ per gallon. The federal special fuels tax is assessed at 24.3¢ per gallon on diesel fuel, and 13.2¢ per gallon on liquefied petroleum gas and gasoline gallon equivalent of compressed natural gas. Gasoline and special fuels are also subject to a Leaking Underground Storage Tank fee of 0.1¢ per gallon. Several federal tax credits are available, including the alternative fuel credit, alternative fuel mixture credit, and renewable diesel credit. In addition, the federal government administers red dyed diesel, which is diesel fuel used for off-highway uses. The state exempts red dyed diesel from state fuel taxes. For more information, visit the Internal Revenue Service website on fuel taxes.

State Comparisons

Every state assesses a tax on motor fuels. The average state tax is 27.3¢ per gallon of gasoline and 28.9¢ per gallon of diesel. California assesses the highest gasoline tax at 59.6¢ per gallon while Pennsylvania has the highest tax on diesel at 74.1¢ per gallon. Florida has the lowest taxes on gasoline and diesel at 4¢ per gallon.9

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1Parts 1 (gasoline) and 2 (special fuels) of Article 27 of Title 39, C.R.S. In 1935, Article X, Section 18, Colorado Constitution was enacted. This amendment specifies that motor fuel revenue may only be used for transportation-related activities.
2Section 39-27-105, C.R.S.
3Section 39-27-102, (1)(a)(II)(A), C.R.S.
4Section 39-27-101 (12), C.R.S.
5Section 39-27-102, (1)(a)(II)(B), C.R.S.
6Sections 39-27-102, (1)(a)(VI)(F), 39-27-102, (1)(a)(VII)(F), and 39-27-102, (1)(a)(VIII)(F), C.R.S.
7Section 39-27-102.5, C.R.S.
8Sections 43-4-201 through 207, C.R.S.
9Energy Information Association. “Federal and State Motor Fuel Taxes”. July 2024. https://www.eia.gov/petroleum/marketing/monthly/xls/fueltaxes.xls.

 
 
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