Vehicle Emissions Inspection & Maintenance (I/M): General Information for Motorists

On this page:

General Information
Vehicle Warranty and Repair Information
State and Local Government I/M Websites

Vehicle inspection and maintenance (I/M) programs help improve air quality by identifying cars and trucks with high emissions and that may need repairs. Owners or operators of vehicles with high emissions are notified to make any repairs so that emissions are within legal limits. The 1990 Amendments to the Clean Air Act (CAA) established I/M requirements for several areas across the country. This page contains general information of interest to motorists subject to I/M.

General Information

Overview of Vehicle Inspection and Maintenance (I/M) Programs (pdf) (October 2021, EPA-420-F-21-067)
This document provides information on I/M programs such as where I/M programs are required and an overview of I/M testing.
Overview of Vehicle Repair and Replacement Assistance Programs (pdf) (May 2023, EPA-420-F-23-013)
This document explores how some state and local I/M programs include provisions for vehicle repair or replacement assistance programs for low-income motorists.

Vehicle Warranty and Repair Information

Fact Sheet: Emission warranties for 1995 and newer light-duty cars and trucks under 8,500 pounds gross vehicle weight rating (GVWR) (pdf) (EPA-420-F-15-035, October 2015)
Fact Sheet: If Your Car Just Failed An Emissions Test... You May Be Entitled To Free Repairs (pdf) (EPA420-F-95-014, December 1995)
Parts List for Section 207(a) Emission Design and Defect Warranty (pdf) (EPA420-B-91-001, July 1991) This document contains a list of vehicle parts that are considered "emission related" for purposes of warranty emission repairs.

State and Local Government I/M Websites

I/M testing is conducted by state and local government agencies. Because I/M programs vary from area to area, please visit the applicable link below for more information on your area’s I/M program including locations of testing sites, testing frequency, vehicles covered, repair waivers, out-of-state vehicles / reciprocity, etc. Note, clicking these links will exit the EPA site.

Arizona My AZ Car

California Smog Check Program

Colorado Motor Vehicle Emissions

Connecticut Emissions Testing Program

Delaware Vehicle Inspection and Maintenance

District of Columbia Vehicle Inspections

Georgia Clean Air Force

Idaho Ada County Emission Testing

Illinois Air Team Vehicle Emissions Testing Program

Indiana Clean Air Car Check

Louisiana Motor Vehicle Inspection and Maintenance

Maine Enhanced Vehicle Inspection and Maintenance