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Emissions Testing Requirements in Indiana

3 min read

Indiana requires emissions testing for vehicles registered in certain counties to help monitor and reduce air pollution. This program is managed by the Indiana Department of Environmental Management (IDEM) in conjunction with the Bureau of Motor Vehicles (BMV). Understanding the requirements can help vehicle owners remain compliant and avoid registration delays.

Counties Requiring Emissions Testing

As of 2025, emissions testing is required for vehicles registered in the following counties:

  • Lake County
  • Porter County

These counties are part of Indiana's Clean Air Car Check program due to higher levels of ground-level ozone and other pollutants.

Vehicles Subject to Testing

The emissions testing program applies to gasoline-powered vehicles and certain light-duty trucks that meet the following criteria:

  • Model year is between 1976 and the current year minus four (i.e., vehicles older than four years)
  • Vehicle is registered in Lake or Porter County
  • Vehicle has a gross vehicle weight rating (GVWR) of 9,000 pounds or less

Diesel-powered vehicles, electric vehicles, and hybrid vehicles registered in these counties may be subject to different requirements or exempted based on individual evaluations.

Testing Frequency

Vehicles subject to emissions testing must be tested every two years. The test year is determined by the vehicle’s model year:

  • Even model years test in even-numbered years
  • Odd model years test in odd-numbered years

Testing is typically required before a vehicle can be registered or renewed.

Where to Test

Testing must be completed at an authorized Clean Air Car Check station. A full list of locations, hours, and wait times is available on the official Clean Air Car Check website.

Test Procedure

The emissions test includes:

  • Onboard Diagnostics (OBD II) check for 1996 and newer vehicles
  • Tailpipe emissions test for older vehicles (where applicable)
  • Visual inspection of the emissions control components

Vehicles that fail the test must be repaired and retested before registration renewal can proceed.

Fees

Emissions testing is free for vehicle owners. However, repairs required to bring a vehicle into compliance are the responsibility of the owner.

Exemptions

Some vehicles may qualify for exemptions:

  • Vehicles that are four model years old or newer
  • Motorcycles
  • Recreational vehicles (RVs)
  • Vehicles registered as historic or antique
  • Diesel vehicles over 9,000 pounds GVWR
  • Electric vehicles

If you believe your vehicle qualifies for an exemption, documentation must be submitted to IDEM or the Clean Air Car Check program for approval.

Out-of-Area Exemptions

If your vehicle is temporarily out of the testing area during the required period (e.g., for college or military service), you can apply for a temporary exemption by contacting IDEM and providing supporting documents.

Staying Compliant

Failing to complete the required emissions test will result in a denial of registration renewal. To avoid this, always:

  • Keep track of your testing schedule
  • Maintain your vehicle’s emission systems
  • Use authorized testing centers

Understanding all aspects of vehicle ownership and compliance in Indiana helps prevent legal and registration issues. Here are some related resources: