Emissions Testing by State

Browse emissions testing requirements and smog check rules for all 50 U.S. states and Washington, D.C. Each state page explains who must test, how often inspections are required, which vehicles are exempt, and where to find certified testing stations.

Select Your State

Emissions testing programs vary across the country. Some states test statewide, others only in certain metro areas, and several have no program at all. Pick your state below to see current 2025 rules, vehicle exemptions, and a city-by-city directory of approved testing locations.

Alabama

24 Stations

Alaska

5 Stations

Arizona

54 Stations

Arkansas

26 Stations

California

2,825 Stations

Colorado

68 Stations

Connecticut

30 Stations

Delaware

6 Stations

District of Columbia

3 Stations

Florida

133 Stations

Georgia

368 Stations

Hawaii

30 Stations

Idaho

7 Stations

Illinois

78 Stations

Indiana

38 Stations

Iowa

27 Stations

Kansas

14 Stations

Kentucky

20 Stations

Louisiana

46 Stations

Maine

35 Stations

Maryland

154 Stations

Massachusetts

160 Stations

Michigan

37 Stations

Minnesota

31 Stations

Mississippi

4 Stations

Missouri

119 Stations

Montana

18 Stations

Nebraska

18 Stations

Nevada

152 Stations

New Hampshire

73 Stations

New Jersey

67 Stations

New Mexico

45 Stations

New York

242 Stations

North Carolina

279 Stations

North Dakota

13 Stations

Ohio

48 Stations

Oklahoma

20 Stations

Oregon

27 Stations

Pennsylvania

317 Stations

Rhode Island

39 Stations

South Carolina

34 Stations

South Dakota

10 Stations

Tennessee

39 Stations

Texas

602 Stations

Utah

135 Stations

Vermont

33 Stations

Virginia

180 Stations

Washington

51 Stations

West Virginia

25 Stations

Wisconsin

65 Stations

Wyoming

8 Stations

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Understanding Emissions Testing Requirements

Everything you need to know about emissions testing programs, how this directory helps, and where to find more detailed guides.

How Emissions Testing Works

Emissions testing programs in the United States help reduce air pollution and ensure vehicles meet federal Clean Air Act standards. Depending on the state and vehicle type, inspections may include OBD-II diagnostics, tailpipe emissions tests, gas-cap or evaporative system checks, opacity tests for diesel vehicles, or combined safety-and-emissions inspections.

Most states only require emissions testing in metro areas that do not meet federal air-quality goals, while others enforce statewide programs. Requirements vary by model year, vehicle type, fuel type, and registration address. Major metro regions such as Los Angeles, Phoenix, Denver, Houston, and New York typically maintain the most comprehensive testing programs.

Why Use This Directory

This directory makes emissions testing straightforward by providing clear, consistent information for every state. Instead of sorting through multiple DMV and environmental agency websites, you can browse standardized summaries that explain exactly what your vehicle needs.

Each state page includes:

Current testing requirements
Exemption rules
Inspection frequency
Diesel, hybrid, and EV guidance
What happens during the test
Approved testing stations by city

All listings are verified and updated as states adjust their regulations, ensuring you always have accurate, easy-to-follow information.

Related Guides

Explore our most popular resources on emissions testing and smog checks. Learn how OBD-II inspections work, how to prepare your vehicle for a test, common reasons failures occur, and which vehicles qualify for exemptions.

You'll also find guides that explain testing requirements when moving to a new state, tips for passing your smog check on the first try, and what to do if your vehicle fails. These articles help drivers stay compliant with state regulations and understand the testing process from start to finish.

Browse All Guides

Frequently Asked Questions

Discover quick and comprehensive answers to common questions about our platform, listings, and services.

Some states require emissions testing or smog checks statewide, while others test only in selected metro areas. Major testing states include California, Arizona, Colorado, Texas, New York, and Maryland, along with several others that operate regional programs. The easiest way to check is to select your state in this directory and review the current 2025 rules.

A number of states have no routine emissions testing requirement for most passenger vehicles, while others limit testing to special cases or certain heavy or commercial vehicles. Because rules change and local programs can differ, select your state in the directory to see whether any emissions or smog-check requirements apply where you live.

An emissions test, often called a smog check, measures the pollutants coming from your vehicle’s exhaust and verifies that key emissions-control systems are working properly. States may use OBD-II computer checks, tailpipe tests, gas-cap pressure tests, or opacity tests for diesel vehicles. Passing the test is usually required before you can renew your vehicle registration in testing areas.

Whether you need an emissions test depends on your state, your registration ZIP code, and your vehicle’s model year, weight, and fuel type. Many states test only in specific counties or metro areas and exempt the newest model years. Select your state in this directory to see the exact 2025 requirements and exemptions for your vehicle.

Most emissions programs require testing every one or two years, usually tied to your registration renewal month. Some states require annual tests for older or diesel vehicles and biennial tests for newer cars. Your state notice or online lookup will show your test cycle; you can also check your state’s page in this directory.

A standard emissions test or smog check usually takes 10 to 20 minutes once your vehicle is in the bay. The visit may take longer if there is a line or if your vehicle requires a dynamometer or more complex inspection. Bringing current registration and ensuring the check engine light is off can help speed up the process.

All-electric vehicles are exempt from tailpipe emissions testing nationwide because they produce no exhaust. Hybrid requirements vary by state. Many states test hybrids just like gasoline vehicles, while others exempt the newest hybrid model years for a set period. Check your state’s page to see how hybrids are treated in 2025.

Several states include diesel vehicles in their emissions or opacity testing programs, especially in metro areas with air-quality concerns. Programs in states such as California, Arizona, Colorado, New York, and Maryland may require testing for certain diesel weight classes or model years. Requirements are very state-specific, so review your state page for details.

Emissions test fees vary by state and by station, but most drivers pay between $10 and $40 per inspection. Some states regulate prices at state-run facilities, while private stations can set their own fees. Your state page lists typical costs and whether retests are free or discounted after repairs.

Select your state in the directory to browse approved emissions testing locations by city. Each state page includes a grid of testing stations so you can quickly find a smog-check or emissions-test provider near you in any area where testing is required.

If your vehicle fails, you typically must complete emissions-related repairs and pass a retest before renewing registration. Many states offer one free retest within a set time window and may provide repair waivers or cost-based exemptions if you spend over a specified amount on documented repairs. Your state page explains the exact retest and waiver rules.

Many states exempt vehicles within the first three to seven model years from emissions testing, assuming newer vehicles produce lower emissions and already meet modern standards. The length of the new-vehicle exemption window and renewal schedule is different in each state, so check your state’s rules for the current model year range.

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