Where to get emissions testing in Longmont

Longmont is in Boulder County, which requires emissions testing for most vehicles registered there. You can have your vehicle tested at any Colorado Department of Transportation (CDOT) approved testing station — you do not have to go to a specific location. Several private repair shops and service stations in Longmont and surrounding areas hold CDOT approval and perform the test.

To find an approved station near you, visit the Colorado Department of Public Health and Environment (CDPHE) website and search their list of licensed testing facilities by county. The list includes the station's address, phone number, and hours. Call ahead before you go, because not all stations accept walk-ins, and some require appointments during certain seasons.

The test itself takes about 30 minutes. You will need your vehicle's registration and proof of insurance. Bring your keys and be prepared to stay while the technician runs the test — you cannot leave the vehicle unattended during the process.

Key Takeaways

  • Longmont vehicles need emissions testing every two years, and the test must happen within 60 days before your registration expires.
  • You can visit any CDOT-approved testing station in Boulder County, not just one in Longmont, and the test costs between $25 and $35 depending on the station.
  • The Colorado Department of Public Health and Environment maintains the official list of approved stations, searchable by county and location.
  • If your vehicle fails, you have 60 days to repair it and retest at no additional charge at the same station.

Timing and registration renewal

Your emissions test must be completed within 60 days before your vehicle registration expires. If you test too early, the result will not count toward your renewal. Check your registration card or online account with the Colorado Division of Motor Vehicles (DMV) to find your exact expiration date.

Many people wait until the last month, which creates crowding at testing stations. If you test in the month before expiration, you avoid the rush and still have time to address a failure. If your vehicle fails the test, you have 60 days from the failure date to repair it and retest — the retest is free at the same station.

You cannot renew your registration online or by mail without a passing emissions result. The testing station sends the result directly to the Colorado DMV, so you do not need to carry a paper certificate. Once the DMV receives the passing result, you can complete your registration renewal through the DMV website, by mail, or at a local county office.

What happens if your vehicle fails

A failure means your vehicle's emissions are above the legal limit for one or more pollutants — usually nitrogen oxides, particulate matter, or hydrocarbons. The testing station will give you a written report showing which pollutant exceeded the standard and by how much. This report is your starting point for repairs.

Common reasons for failure include a faulty oxygen sensor, a loose gas cap, a malfunctioning catalytic converter, or engine problems that trigger the check-engine light. Some failures are inexpensive to fix; others require significant repair work. Take the failure report to a mechanic and ask them to diagnose the problem based on the specific pollutant that failed.

You have 60 days from the failure date to repair your vehicle and return to the same testing station for a retest at no charge. If you retest within that window and pass, you can then renew your registration. If you do not retest within 60 days, you will need to pay for a new initial test and start the process over.

Cost and what to bring

The emissions test costs between $25 and $35, depending on which testing station you choose. Prices are set by individual stations, so calling ahead can help you find the lowest cost option. Some stations charge slightly more for heavy-duty vehicles or diesel engines.

Bring your vehicle registration card and proof of insurance. You will also need your keys and your vehicle's odometer reading — the technician will record this during the test. If your vehicle has a check-engine light on, tell the technician before the test begins; some stations will still test you, but others may refuse until the light is addressed.

Payment methods vary by station. Most accept cash and credit cards, but confirm when you call to make an appointment. Some stations offer discounts if you pay in cash or if you are a regular customer.

Vehicles exempt from testing

Not all vehicles registered in Boulder County need emissions testing. Vehicles that are model year 1981 or older are exempt. Vehicles registered as antique, classic, or collector vehicles are also exempt, even if they are newer. Motorcycles and mopeds do not require emissions testing in Colorado.

Electric vehicles and plug-in hybrids are exempt from tailpipe emissions testing, though they still need to pass a visual inspection if required by your county. Vehicles registered as temporary or for off-road use only do not need testing. If you are unsure whether your vehicle is exempt, check the CDPHE website or call your county clerk's office.

Online resources and next steps

The Colorado Department of Public Health and Environment maintains the official testing station directory at their website. You can search by county, city, or station name. The site also explains what pollutants are tested, why emissions testing matters, and what to do if you have questions about your test results.

The Colorado Division of Motor Vehicles website lets you check your registration expiration date and renewal status. You can also renew your registration online once you have a passing emissions result, without returning to a county office.

If you have a dispute about your test result or believe the test was performed incorrectly, contact the CDPHE directly. They oversee all testing stations and can investigate complaints. Keep your test receipt and failure report if you plan to file a complaint.

Frequently Asked Questions

Can I test my vehicle in a different county?

Yes. You can visit any CDOT-approved testing station in Colorado, not just one in Boulder County. The result is valid for registration renewal in Longmont as long as it is within 60 days of your expiration date and the station is officially approved.

What if I move out of Longmont before my registration expires?

If you move to a county that does not require emissions testing, you do not need to retest. If you move to another county that does require it, you will need a test from an approved station in your new county before you renew. Contact your new county clerk's office to confirm their requirements.

Do I need to pass a visual inspection before the emissions test?

Boulder County does not currently require a separate visual inspection for most vehicles. The emissions test itself is the only requirement. However, if your vehicle has a check-engine light on, some testing stations will not test until you address it.

How long does it take to get my test results?

The testing station sends results to the Colorado DMV when ready after the test is complete. You should see the result in your DMV account within one business day. You do not need to wait for a paper certificate — the electronic result is sufficient for registration renewal.

What if I fail and cannot afford repairs right away?

You have 60 days from the failure date to repair and retest. If you cannot complete repairs within that time, you will need to pay for a new initial test once you are ready. Some repair shops offer payment plans or financing for major repairs — ask when you get your estimate.