Air Care Colorado is Colorado's official vehicle emissions testing program

Air Care Colorado is the state-run emissions testing network that Colorado uses to check whether your vehicle meets air quality standards. It is not a single location — it is a program run by the Colorado Department of Public Health and Environment, with testing stations operated by private contractors across the state. When Colorado law requires you to have an emissions test, you go to an Air Care Colorado station to get it done.

The program exists because Colorado has air quality problems in certain areas, particularly around Denver and the Front Range. The state uses emissions testing to identify vehicles that pollute more than allowed and to keep records of which vehicles have been tested. If you live in or frequently drive through a county that requires testing, you will need to pass an Air Care Colorado test before you can renew your vehicle registration.

Key Takeaways

  • Air Care Colorado stations are private businesses contracted by the state, not government offices, and you can find the nearest one through the official Air Care Colorado website or by calling their customer service line.
  • The test itself takes about 10 minutes and costs between $7 and $10 depending on your vehicle type, and you pay the testing station directly.
  • Your vehicle must pass the test before you can renew your registration in a county that requires emissions testing.
  • If your vehicle fails, you have options including repairs, a waiver program if repairs cost too much, or a retest after fixing the problem.

Which Colorado counties require Air Care Colorado testing

Not all of Colorado requires emissions testing. The state divides counties into testing and non-testing areas based on air quality data. Counties in the Denver metro area and along the Front Range — including Denver, Boulder, Jefferson, Adams, Arapahoe, Douglas, and El Paso — require testing. Some counties have partial requirements, meaning only certain areas within the county need testing. Your county assessor's office or your vehicle registration renewal notice will tell you whether testing is required where you live.

If you move to a county that requires testing, or if you register a vehicle in one of those counties, you will need to have the test done before your registration expires. The requirement applies to most gasoline-powered vehicles, though some older vehicles and certain specialty vehicles may be exempt. Check your registration renewal paperwork or contact Air Care Colorado directly to confirm whether your specific vehicle needs testing.

How to find an Air Care Colorado testing station near you

The official Air Care Colorado website has a station locator tool where you enter your zip code and see all nearby testing locations, their hours, and their phone numbers. You can also call Air Care Colorado customer service at 1-888-242-7881 to ask for the closest station. Most stations are open during standard business hours, though some offer evening or weekend appointments.

Testing stations are independent businesses — a gas station, tire shop, or dedicated emissions testing facility — that have contracted with the state to perform the test. They are not Air Care Colorado employees. This means hours, wait times, and customer service vary by location. If one station is busy or inconvenient, you can go to any other Air Care Colorado station in the state; the test results are recorded in the same statewide system regardless of which station you visit.

What happens during an Air Care Colorado emissions test

The test itself is straightforward and takes about 10 minutes. A technician at the station will connect a probe to your vehicle's tailpipe and measure the emissions coming out. For most vehicles, this is a straightforward tailpipe test that checks carbon monoxide, nitrogen oxides, and particulate matter. The technician does not need to take your vehicle apart or do any invasive work.

Your vehicle must be in reasonable operating condition for the test to work — the engine should start and run normally. If your check engine light is on, the vehicle may fail the test or the station may not be able to test it until you address the problem. Bring your registration paperwork and a photo ID. The test costs between $7 and $10 depending on your vehicle type (motorcycle, passenger car, truck, or diesel vehicle), and you pay the testing station directly, not the state.

What to do if your vehicle fails the Air Care Colorado test

If your vehicle fails, you will receive a report showing which emissions exceeded the limit. You then have several options. The most straightforward is to have the problem fixed and return for a retest at the same or a different Air Care Colorado station. The retest costs the same as the initial test. You have until your registration expires to pass the test, so you have time to get repairs done.

If repairs are expensive, Colorado offers a repair cost waiver program. If the estimated cost to fix the emissions problem is $500 or more (the threshold varies slightly), you may be able to get a waiver that allows you to renew your registration without passing the test. You will need a written repair estimate from a mechanic to explore for the waiver. Contact Air Care Colorado or your county assessor's office for the waiver process process and current cost thresholds.

Some vehicles also may have access to for a hardship waiver if you cannot afford repairs at all. This is less common and has stricter requirements, but it is worth asking about if you are in financial hardship. The testing station or Air Care Colorado customer service can tell you whether your situation qualifies.

How Air Care Colorado test results affect your registration

When you pass an Air Care Colorado test, the result is recorded in the state's system and linked to your vehicle's identification number. When you renew your registration online, by mail, or in person at your county assessor's office, the system checks whether a current passing test is on file. If it is, your registration renewal proceeds normally. If no passing test is on file and your county requires testing, your registration will not be renewed until you pass the test.

A passing test result is valid for two years from the date of the test. If your registration expires before the two-year mark, you will need a new test before you can renew again. The test result itself does not expire — it is the registration renewal that triggers the requirement to have a current test on file.

Common reasons vehicles fail Air Care Colorado testing

The most common reason for failure is a vehicle that is not being maintained properly. A vehicle with worn spark plugs, a clogged air filter, old oil, or a failing catalytic converter will often produce emissions that exceed the limit. Regular maintenance — oil changes, air filter replacement, and spark plug replacement on schedule — prevents most failures.

A vehicle with the check engine light on will usually fail or cannot be tested at all. The light indicates a problem with the emissions control system, and that problem must be diagnosed and fixed before testing. A mechanic can read the diagnostic code using a scanner to find out what is wrong. Sometimes the code is something straightforward like a loose gas cap; other times it points to a more serious issue like a failing oxygen sensor or catalytic converter.

Vehicles that have been modified — such as removing or disabling the catalytic converter or oxygen sensors — will fail. These modifications are illegal in Colorado and in most states. If your vehicle has been modified, you will need to have the emissions control equipment restored to factory condition before it can pass the test.

Frequently Asked Questions

Can I test my vehicle at any Air Care Colorado station, or do I have to go to a specific one?

You can go to any Air Care Colorado station in the state. The test results are recorded in the same statewide system, so it does not matter which location you choose. Pick whichever station is most convenient for your schedule and location.

What if I just bought a used vehicle and it has not been tested yet?

If you register the vehicle in a county that requires testing, you will need to pass an Air Care Colorado test before your registration is valid. Some counties give you a grace period (usually 30 days) after you register a vehicle to get the test done. Check your registration paperwork or contact your county assessor's office to see whether a grace period applies to you.

Do I need an appointment, or can I just show up?

Most Air Care Colorado stations accept walk-ins, but some require appointments, especially during busy times. Call the station ahead of time or check the Air Care Colorado website to see whether the location you plan to visit takes appointments or walk-ins. Having an appointment usually means a shorter wait.

What happens if I do not get an emissions test and my registration expires?

If your county requires testing and you do not have a passing test on file, your registration will not renew. Driving with an expired registration is illegal and can result in a traffic citation. If you realize you need a test, get one done as soon as possible and then renew your registration.

Can I test a vehicle that is not registered to me?

You can take any vehicle to be tested, but the test result is recorded under that vehicle's identification number. If you are testing a vehicle you are considering buying, the test result will not transfer to your name once you register it — the new owner will need their own test. If you are testing a vehicle on behalf of someone else, bring that person's registration paperwork and photo ID, or have them present at the test.