How Much Is an Emissions Test in Colorado? Fees by Vehicle and Fuel

An emissions test in Colorado costs $35 for most gasoline and hybrid vehicles from model year 1982 or newer, and $20 for gasoline vehicles from 1981 or older.¹ Diesel testing is handled by independent stations and priced separately. Those are the flat rates at Air Care Colorado stations, and they took effect in 2025 after the state raised its fee ceilings, so drivers who last tested two years ago will pay more than they remember.

Fees by Vehicle Type

Air Care Colorado charges by model year, and how often you pay depends on the same category:

1982 and newer gasoline or hybrid vehicles: $35, tested every two years.
1981 and older gasoline vehicles without collector plates: $20, tested every year.
1982–1994 vehicles with collector plates: $35, tested every five years.
1976–1981 vehicles with collector plates: $20, tested every five years.
1975 and older vehicles with collector plates: exempt, no fee.

Collector-plated vehicles registered before September 1, 2009, whose registration has never lapsed or changed ownership, are grandfathered in and fully exempt regardless of model year.²

Diesel Testing Costs More and Varies by Shop

Air Care Colorado stations do not test diesel-powered vehicles.¹ Diesel owners have to use one of the state’s licensed diesel emissions testing stations, categorized for light-duty, heavy-duty, or both.³ Because these are independent shops, prices are set by each station rather than by the state. Diesel testing generally runs higher than a gasoline test because of the opacity equipment involved. Call ahead for a quote; there’s no single published diesel fee.

When You Pay Nothing

Plenty of Colorado drivers don’t owe a fee at all. The testing program only covers vehicles registered in the Denver metro area and the North Front Range, meaning all or parts of Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer, and Weld counties.⁴ Registered outside those counties, and you skip the test and the fee.

Inside the program area, these vehicles are also exempt:

New gasoline and hybrid vehicles, for the first seven model years. In 2026, that means model years 2020 through 2026 are exempt for renewals.
New diesel vehicles, for the first four model years.
All-electric vehicles, always.
Motorcycles, autocycles, kit cars, horseless carriages, street rods, and farm vehicles, always.⁵

There’s also a way to avoid the station entirely. Colorado’s RapidScreen program uses roadside sensors to measure emissions as you drive past. A clean reading approves you for the cycle, and your registration renewal postcard will tell you if you qualified.⁶ There’s no charge for the screening itself.

Why Fees Went Up in 2025

Colorado law used to cap inspection fees at $25 for newer vehicles and $15 for older ones. In June 2025, Governor Polis signed SB 25-321, giving the Colorado Department of Public Health and Environment authority to set fees administratively, with new ceilings of $50 for 1982-and-newer vehicles and $30 for 1981-and-older vehicles.⁷ CDPHE set the current rates at $35 and $20, below those maximums. Because the department can adjust fees without new legislation, expect the possibility of further changes in future cycles.

Costs After a Failed Test

Free Retest Window

If your vehicle fails, you get one free retest within 10 calendar days of the failure. Miss that window and you pay the full fee again.⁸ Even a gas cap failure requires a complete retest with the replacement installed, since the cap affects the emissions control system as a whole.

Repair Waivers by Spending Threshold

If repairs still don’t bring the vehicle into compliance, Colorado offers a waiver that lets you register anyway once you’ve spent a minimum on emissions-related work in the past six months and failed a second test:

Gasoline vehicles, 1968 and newer: at least $715 in repairs.
Gasoline vehicles, 1967 and older: at least $75 in repairs.
Light-duty diesel (14,000 lbs or less): at least $750 in repairs.
Heavy-duty diesel (14,010 lbs or more): at least $1,500 in repairs.⁹

You’ll need your most recent failed emissions report and receipts documenting the spending. Waiver applications go through the Colorado Department of Revenue at 303-205-5603.⁸

If you were flagged through on-road screening and can’t afford the repairs, ask the Department of Revenue about the Regional Air Quality Council’s Repair Your Air program, which offers financial assistance valued at more than $715 to vehicles referred in by state technicians or DOR.¹⁰

Skipping the Test Blocks Your Registration

Compliance is tied directly to registration. If your vehicle requires a test and you don’t get one, the county clerk’s office will not renew, and driving on expired plates exposes you to citations and possible towing. Your renewal postcard tells you plainly whether a test is required for the cycle.

Disputing a Charge

If a station billed you incorrectly, common examples being a fee charged on an exempt vehicle or a duplicate charge for one inspection, start at the station. If that doesn’t resolve it, call the Air Care Colorado hotline at 303-456-7090 in the Denver metro area or 970-247-8378 in the North Front Range.¹ You can also file an air quality complaint with CDPHE’s Air Pollution Control Division, which investigates testing station compliance.¹¹

1
AirCare Colorado. Need to Know
2
Department of Revenue – Motor Vehicle. Gas Emissions Requirements
3
Department of Revenue – Motor Vehicle. Licensed Diesel Emissions Testing Stations
4
Colorado Department of Public Health and Environment. Emissions Inspections for Gasoline-Powered Vehicles
5
Department of Revenue – Motor Vehicle – Colorado DMV. Emissions
6
Department of Revenue – Motor Vehicle. What Is RapidScreen?
7
Colorado General Assembly. SB25-321 Motor Vehicle Emissions Inspection Facilities
8
AirCare Colorado. FAQ: Quick Consumer Information
9
Department of Revenue – Motor Vehicle. Emissions Waivers
10
RAQC. Repair Your Air
11
Colorado Department of Public Health and Environment. Submit an Air Quality Complaint to the Air Pollution Control Division