Quick Consumer Information

Hours of Operation

Monday to Friday, 8 a.m. to 5:30 p.m. and Saturdays, 8 a.m. to 1 p.m.
Closed Sundays and state holidays.

PLEASE NOTE: Animals are not allowed in the waiting booths. Please wait with your pets outside of the building. Service animals, specifically trained to aid persons with disabilities, are welcome.

Look up a vehicle's recent emissions testing history. Vehicle Test History

Make sure you need a test before you present your vehicle for testing! State regulation requires testing centers to test all vehicles that are presented for testing. Emissions inspectors are prohibited from making a judgment on whether your vehicle really needs a test. No refunds can be given for emissions tests on vehicles that were not actually due for a test. If you are not sure, call the Air Care Colorado Hotline at 303-456-7090, or your county motor vehicle office to ask. Effective July 1, 2001, window stickers were eliminated by state law.

1982 and newer vehicles require an enhanced emissions test every two years at a cost of $25.

1981 and older vehicles require a two-speed idle test every year at a cost of $15.00.

Vehicle Identification Number (VIN) verifications are also available at a cost of $20.00.

Payment for the test may be made by cash, check or charge. (Please make checks payable to: ACC.)

Please Note: We cannot accept "temporary" checks, i.e., checks without printed identification.


There is a 30-day grace period for your annual or biennial emissions test expiration. However, keep in mind that more than 30 days over the expiration could cost you a $50 ticket. To request an extension, please visit your Motor Vehicle office.


If your vehicle fails the emissions test, the first retest is free within ten calendar days (not ten business days). If the 10th calendar day falls on a Sunday or holiday when the stations are closed, the free retest will be extended to the 11th day.


Avoid waiting in line. Come on Saturdays, early mornings, and during the middle two weeks of the month.

High volume times to avoid are Mondays, the lunch hour, the first business day after any holiday, and the first few and last few days of the month.

Front wheel and all wheel drive vehicles with low profile rim sizes 17 inches or larger in diameter or vehicles with wheel sizes larger than 34 inches must be tested on special dynamometers, capable of testing over and under-sized tires, at our Sheridan, Ken Caryl and Ft. Collins stations. Please keep in mind that not all stations are equipped with specialized dynamometers.

  If your vehicle has never before been registered within the state of Colorado, in addition to an emissions inspection, you must also obtain a Vehicle Identification Number (VIN) verification prior to registering the vehicle. VIN Verifications may be obtained at any Air Care Colorado inspection station, either during the vehicle inspection, or, if no inspection is needed, at the station office. If your vehicle requires an inspection, simply let the inspector know that you need a VIN verifiaction as well as an inspection when you arrive. However, if you do not need an inspection, do not drive into the testing lanes, request the verification inside the station office. The fee is $20.

Newer Vehicles
If the vehicle is less than six years old and has never before been registered anywhere in the state of Colorado, you do not need an emissions inspection. HOWEVER, in order to register the new vehicle in Colorado, you will need a VIN verification. Do not drive the vehicle into the testing lanes for a VIN verification; request a VIN verification inside the office.

The following provide VIN verifications:
  • Centralized Air Care Colorado emissions inspection centers
  • Licensed diesel emissions inspection stations
  • Some motor vehicle dealerships
  • Some County Clerk and Recorder offices
  • Some law enforcement agencies
Important Note: Some county clerks and law enforcement agencies do not provide this service. Call ahead to make sure this service is available before going to a county clerk's office or law enforcement agency for a VIN verification. For more information on the VIN verification requirement, call the Colorado Division of Motor Vehicles at 303-205-5603 or your county motor vehicle office.

A vehicle may receive an alternative test for one of several reasons: • The required Onboard Diagnostic (OBD) inspection may not be able to be performed on a vehicle due to a communication problem that prevents the vehicle’s computer from communicating with the test equipment. Therefore, an alternative I/M 240 inspection may be performed. • The required Onboard Diagnostic (OBD) inspection may not be able to be performed on a vehicle due to the vehicle’s OBD system not being ready. While this does not necessarily mean that the vehicle has a problem, it does indicate that the vehicle’s OBD computer has not yet completed its self-tests (or become “Ready”). Therefore, an alternative IM240 inspection may be performed. • A few vehicles are selected at random to receive an I/M 240 inspection instead of the Onboard Diagnostic (OBD) inspection to ensure the quality of the various inspection types.

There are up to 11 readiness monitors in a vehicle that allow the vehicle’s Onboard Diagnostic system (computer system) to monitor for potential emissions problems. Some of these monitors run whenever the vehicle is operating while others run periodically. Once a monitor has run, it is set to “Ready” indicating that the system’s self-evaluation is complete. Part of Colorado’s OBD emissions test requires certain monitors to be set to “Ready” to ensure the system has properly performed this self evaluation. All OBD-inspected vehicles must have the Catalytic Converter, Oxygen Sensor, and Heated Oxygen Sensor (if so equipped) monitors set to “Ready” during the inspection. Vehicles model year 2000 and older can have two remaining monitors “Not Ready” while vehicles 2001 and newer can only have one unset monitor. Specific conditions must be met while driving for the Readiness Monitors to be set to “Ready.” Some vehicle manufacturers provide specific driving procedures to set the necessary monitors to ready.

Vehicle Unable to Test If you received a “Vehicle Unable to Test” form during your inspection, it was for any of the reasons checked by the inspector. Unsafe, inaccessible, or malfunctioning equipment must be repaired before the vehicle can be inspected.