Colorado Low Emission Vehicle Program History

On June 19, 2018, Governor Hickenlooper signed Executive Order B 2018 006, Maintaining Progress on Clean Vehicles. The executive order explains that the federal government has announced its intention to roll back vehicle greenhouse gas (GHG) standards for model years 2022-2025. Rolling back these standards would negatively impact Colorado’s ability to meet its GHG reduction goals.
The executive order directs the Colorado Department of Public Health and Environment (CDPHE) to do the following:
  • develop a rule to establish a Colorado Low Emission Vehicle (LEV) program, which incorporates the requirements of the California LEV program, and
  • propose that rule to the Colorado Air Quality Control Commission (AQCC) during its August 2018 meeting for possible adoption into the Colorado Code of Regulations by December 30, 2018.


On November 16, 2018, the Colorado Air Quality Control Commission (AQCC) adopted Regulation 20, the Colorado Low Emission Automobile Regulation (CLEAR). As of automotive model year 2022, all new light-and-medium-duty vehicles (up to 14,000 pounds GVWR) and Aftermarket Catalytic Converters sold in Colorado must meet Low Emission Vehicle (LEV) standards. These standards helped preserve existing standards applicable in Colorado, and avoid any roll-back of these applicable standards by the federal government. 

In January of 2019, Governor Jared Polis signed an executive order that supported the transition to electric vehicles. 

On August 19, 2019, the AQCC adopted a revision to regulation 20 that incorporated a Zero Emission Vehicle (ZEV) standard that requires a certain percentage of new vehicle sales to be ZEVs starting in the 2023 model year. Learn more about Colorado’s ZEV transition.

On April 21, 2023, the AQCC adopted a revision to regulation 20 that incorporated new regulations for heavy duty vehicles (HD Low NOx), advanced clean trucks (ACT), and large entity reporting (LER). 



Stakeholder Meeting
CDPHE held a stakeholder meeting on August 3, 2018:

Please send any questions or comments about the Colorado Low Emission Vehicle programs to cdphe_colevzev@state.co.us