A Colorado emissions test is required if you register your vehicle in the Denver metro area or parts of the northern Front Range, your vehicle runs on gasoline or diesel, and it’s old enough to have aged out of the new-vehicle exemption. Gasoline vehicles are exempt for their first seven model years; diesel vehicles for their first four. For 2026, that means gasoline vehicles from model year 2020 or newer skip testing entirely, while a 2019 gasoline vehicle now needs its first inspection.1Department of Revenue – Motor Vehicle – Colorado DMV. Emissions If you register outside the program area, you have no testing obligation at all.
Where Testing Applies
The program covers all of Boulder, Broomfield, Denver, Douglas, and Jefferson counties, plus portions of Adams, Arapahoe, Larimer, and Weld counties.2Colorado Department of Public Health and Environment. Emissions Inspections for Gasoline-Powered Vehicles Testing is administered through Air Care Colorado, which operates stations across the region.1Department of Revenue – Motor Vehicle – Colorado DMV. Emissions
You don’t need to track any of this yourself. Your registration renewal postcard will state whether a test is due before you can renew.
Which Vehicles Don’t Need Testing
The largest exemption is for newer vehicles: seven model years for gasoline, four for diesel.1Department of Revenue – Motor Vehicle – Colorado DMV. Emissions Beyond that, several categories are permanently exempt regardless of age:
- All-electric vehicles
- Motorcycles and autocycles
- Kit cars and street rods
- Farm vehicles
- Horseless carriages
Hybrids are not exempt. They follow the same schedule as regular gasoline vehicles, receiving the same seven-model-year exemption and then entering the biennial cycle.3Department of Revenue – Motor Vehicle. Gas Emissions Requirements
Collector vehicles get partial treatment. Model year 1975 and older vehicles with collector plates are fully exempt. For 1976-and-newer collector vehicles, the exemption applies only if the vehicle was registered as a collector’s item before September 1, 2009, and the registration has never lapsed or changed ownership since.3Department of Revenue – Motor Vehicle. Gas Emissions Requirements Miss any of those conditions and the vehicle still needs testing.
How Often You’ll Test
Once past the new-vehicle exemption, gasoline vehicles from model year 1982 and newer test every two years. Vehicles from 1981 and older test annually.2Colorado Department of Public Health and Environment. Emissions Inspections for Gasoline-Powered Vehicles The cycle ties to registration renewal, which is when the state prompts you.
A test is also required outside the regular cycle in two situations: when you sell the vehicle, and when you’re a new resident bringing a vehicle in from out of state. New residents must complete an emissions inspection within 90 days of establishing residency before Colorado registration can be issued.4Air Care Colorado. Need to Know
Selling or Buying a Vehicle
This is where people run into trouble. Colorado law prohibits selling a vehicle required to be registered in the program area without a valid emissions certificate, unless the vehicle qualifies for an exemption with at least twelve months remaining.5Justia Law. Colorado Revised Statutes Title 42 – Section 42-4-310 The seller is responsible for producing the passing certificate at the time of sale.
The rule can catch sellers whose vehicles are still within the new-vehicle exemption. If you’re selling a 2020 gasoline vehicle in 2026, its final exempt year, you have to test it before the sale because there’s less than twelve months of exemption remaining.1Department of Revenue – Motor Vehicle – Colorado DMV. Emissions
A sale certificate is valid for 24 months for 1982-and-newer vehicles and 12 months for 1981-and-older vehicles.5Justia Law. Colorado Revised Statutes Title 42 – Section 42-4-310 Two exceptions apply: wholesale transactions between licensed dealers don’t need pre-sale testing, and inoperable vehicles can be sold untested if the seller gives the buyer written notice disclosing the vehicle hasn’t been tested. Retail sales by dealers are not exempt; if a dealer sells to you, the vehicle needs a valid certificate like any other sale.
What the Test Costs and Involves
An emissions test at an Air Care Colorado station costs $35 regardless of vehicle age or test type.3Department of Revenue – Motor Vehicle. Gas Emissions Requirements Independent stations that test 1981-and-older vehicles may charge less. Cash, check, Visa, Mastercard, and Discover are accepted. No appointment is needed; bring your registration.
The type of test depends on your vehicle’s model year. Roughly model year 2014 and newer gasoline vehicles get an On-Board Diagnostics check, where a technician plugs into the vehicle’s diagnostic port and reads emissions data. Vehicles from 1982 through roughly 2013 get the I/M240 test, driven on a dynamometer that simulates about four minutes of varied driving while sensors measure exhaust. Vehicles from 1981 and older get a two-speed idle test.6Air Care Colorado. How It Works3Department of Revenue – Motor Vehicle. Gas Emissions Requirements
Results upload electronically to the state motor vehicle system. Allow 24 to 72 hours before renewing your registration.7Douglas County Colorado Website. Vehicle Emissions Information
RapidScreen: Testing Without a Station Visit
Some vehicles qualify for a free roadside program called RapidScreen. Air Care Colorado operates monitoring units, housed in white vans and small green roadside boxes, that measure exhaust as vehicles drive past.8Department of Revenue – Motor Vehicle. What is RapidScreen? Two clean readings within a ten-month window, ending at least 90 days before your renewal month, satisfy the test requirement. Your renewal postcard tells you if your vehicle has qualified.
If Your Vehicle Fails
A failed test comes with a Vehicle Inspection Report listing the specific reasons. Make repairs and return; a retest within ten calendar days is free, and after that you pay full price again. You can use any repair shop, or do the work yourself. Air Care Colorado keeps a list of technicians trained specifically in emissions repairs if your usual mechanic can’t diagnose the problem.4Air Care Colorado. Need to Know
If your vehicle still won’t pass after repairs, Colorado offers three waiver paths.
The repair cost waiver applies when you’ve spent a threshold amount on emissions-related repairs and the vehicle still fails a retest. Thresholds vary by vehicle type: $715 for gasoline vehicles 1968 and newer, $75 for gasoline 1967 and older, $750 for light-duty diesel (14,000 lbs or less), and $1,500 for heavy-duty diesel. All spending must be within the past six months, and the vehicle must have previously passed an emissions test in Colorado.9Department of Revenue – Motor Vehicle. Emissions Waivers
The economic hardship waiver applies only to gasoline vehicles. It requires one failed test within the past six months, current enrollment in an approved public assistance program, and no more than two vehicles titled in your name. No minimum repair expenditure is required.9Department of Revenue – Motor Vehicle. Emissions Waivers
The diagnostic waiver is a third option when a CDPHE emissions technical center determines the failure can’t be resolved through further repairs. Contact the Colorado DMV Emissions Office at 303-205-5603 for eligibility.4Air Care Colorado. Need to Know
If You Skip the Test
There’s no standalone fine for missing an emissions test, but you can’t renew your registration without one. If registration lapses, late fees accumulate at $25 per month or partial month, capped at $100.10Department of Revenue – Motor Vehicle. FAQs – Registration Driving on expired tags also exposes you to a traffic stop. New residents who don’t register within 90 days face a potential $500 civil penalty and additional monthly fines.
Extensions for Students and Military
If your vehicle is registered in the program area but is physically out of state because you or an immediate family member is on active military duty or attending school, you can apply for an extension using form DR 2376, submitted through MyDMV.Colorado.gov or your county clerk’s motor vehicle office.1Department of Revenue – Motor Vehicle – Colorado DMV. Emissions
If the state where the vehicle is located requires emissions testing, submit a passing test from that state. If not, submit a VIN verification form (DR 2698) completed by certified law enforcement or authorized DMV personnel there. Once back in Colorado, the vehicle must be tested within 15 days.
Check your renewal postcard when it arrives, get the test done early if one is required, and give results a few days to upload before completing your renewal.