Gas/Alt. Emissions Requirements

Boulder County requires that gas-powered, alternative fuel, and hybrid vehicles pass an emissions test in order to be registered. Details about requirements and exemptions are listed below as well as on the state’s Gas Emissions Program page.

Registration Renewal

Obtain an emissions test if the statement “Emissions Test is Required” appears on your vehicle registration renewal notice.

• Emissions test results will be electronically posted to your vehicle registration record within minutes.
• Wait about 5 minutes after completion of your test and then renew your registration online or at a MV Express kiosk.

Test Information: Air Care Colorado

Gas-fueled vehicles, hybrid vehicles, and some alternative-fueled vehicles can obtain an emissions test from Air Care Colorado.

• Open 8 a.m.-5:30 p.m. Monday-Friday; 8 a.m.-1 p.m. Saturday
• Locations and Map
  • Local Testing Locations:
    • Boulder: 5655 Airport Boulevard
    • Longmont: 4040 Rogers Road
    • Broomfield: 11609 Teller Street
    • Dacono: 5222 Silver Peak Avenue
• Phone: 303-456-7090
• Cost: $25 for vehicle model years 1982 and newer. $15 for vehicle model years 1981 and older. Cash, personal checks, debit or credit cards are accepted

Air Care Colorado does not test diesel vehicles. Diesel vehicles have different requirements.

2020 Emissions Exemptions

The following vehicles are exempt from emissions requirements:

• Gas/Hybrid/Alt. Fuel vehicles are exempt for the first seven model years. (In 2020, this means vehicles that are 2014 or newer are exempt).
  • Exception: If vehicle ownership is being transferred in the last year of the seven-year exemption, an emissions test will be required. (In 2020, this means that a 2014 vehicle will require an emissions test if there is a transfer of ownership.)
• Vehicles 1975 and older with collector plates
• Vehicles 1976 or newer that have been grandfathered (i.e. registered as a “collector’s item” prior to September 1, 2009 and registration has never lapsed/expired/or had a change of ownership)
• The following vehicle types are exempt: kit cars, all-electric vehicles, motorcycles, horseless carriages, and vehicles registered as street rods

2020 Emissions Requirements

Unless a vehicle is exempt (see above), the following requirements apply:

• Gas/Hybrid/Alt. Fuel vehicles require an emissions test starting in their eighth model year. (In 2020, this means vehicles that are 2013 or older require a test).
  • 1982 and newer require an emissions test every two years.
  • 1981 and older require a test annually.
  • 1976-1988 with collector plates require a test every 5 years.
• Hybrid Vehicles are required to obtain an Onboard Diagnostic (OBD) emissions inspection.
• Alternative Fuel Vehicles require a test. The following single/dual alternative fuel types can be tested at Air Care Colorado:
  • Ethanol
  • Natural Gas
  • Propane
  • Methanol
  • Bio-diesel
  • Propane/gas
  • Methanol/gas
  • Natural gas/diesel
  • Natural gas/gas
  • Ethanol/gas

New Purchases – Sellers & Dealers Must Provide Emissions

• A private seller is required to provide the buyer with a passing emissions test at the time of sale (if the vehicle requires emissions testing). An emissions test that has been used previously for the purpose of vehicle registration/renewal cannot be transferred to the buyer.
• Colorado dealers are required to provide a passing emissions test or a voucher good for one emissions test at the time of sale (if the vehicle requires an emissions test). These vouchers are typically only good for the first three days after purchase, so the buyer has a short window of time in which to get the vehicle tested (and return it if it does not pass).