States that require emissions testing

Emissions testing is required in 34 states plus the District of Columbia, but the rules vary significantly by state, county, and sometimes even by city. Not every state that has a testing program requires it everywhere within its borders — many states only mandate it in certain metropolitan areas or counties with air quality concerns. The federal government sets the baseline standards through the Environmental Protection Agency (EPA), but each state decides whether to adopt a testing program and how strict to make it.

The states with statewide or partial emissions testing programs are: Arizona, California, Colorado, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wisconsin. The District of Columbia also requires testing. However, this list does not mean every resident in these states must test — you need to check your specific county or region.

States without any emissions testing program include Alabama, Alaska, Arkansas, Hawaii, Idaho, Iowa, Kansas, Mississippi, Montana, Nebraska, North Dakota, Oklahoma, South Carolina, South Dakota, West Virginia, Wyoming, and a few others. If you live in one of these states, your vehicle does not need to pass an emissions test to register it.

Key Takeaways

  • Emissions testing is required in 34 states plus DC, but many of these states only require it in specific counties or metropolitan areas, not statewide.
  • You can find out whether your county requires testing by entering your zip code on your state's Department of Environmental Quality or Department of Motor Vehicles website.
  • Testing requirements depend on your vehicle's age, fuel type, and sometimes its weight class — not all vehicles in a testing state must be tested.
  • If your vehicle fails, you typically have 30 to 60 days to repair it and retest before your registration becomes invalid, though this varies by state.
  • States without any testing program include Alaska, Hawaii, Montana, Wyoming, and most of the Great Plains and South.

How to learn about your county requires testing

The fastest way to find out is to visit your state's Department of Environmental Quality, Department of Motor Vehicles, or air quality division website and search for your zip code or county name. Most states have an online tool that tells you when ready whether testing is required where you live. You can also call your local DMV or county air quality office and give them your address — they will tell you in one call.

Some states organize testing by metropolitan statistical area (MSA) rather than by county. For example, in Texas, testing is required in the Houston, Dallas-Fort Worth, and Austin areas but not in rural parts of the state. In California, testing is required in most populated regions but not in rural northern counties. Your zip code matters more than your state — two people in the same state may have different requirements depending on where they live.

If you are moving to a new state or county, check the requirements before you register your vehicle there. Some states will not issue a registration without a passing emissions test, and others will issue a temporary registration that expires once you fail to produce one.

Which vehicles must be tested in your state

Not all vehicles are tested even in states that require testing. Most programs test only passenger cars, light trucks, and SUVs — usually those with a gross vehicle weight rating (GVWR) under 14,000 pounds. Heavy trucks, motorcycles, and vehicles registered as commercial often are exempt.

Age cutoffs vary by state. Some states test all vehicles model year 1996 and newer; others start at 2000 or later. A few states exempt vehicles under a certain age — for example, some do not test vehicles less than 2 years old. Diesel vehicles are sometimes tested under different standards than gasoline vehicles, or exempted entirely in some states.

Your state's DMV or air quality website will list the exact vehicle classes and model years that require testing. When you register your vehicle, the DMV will tell you whether a test is required before they issue your registration.

What happens if your vehicle fails the test

A failed emissions test does not when ready invalidate your registration, but it does trigger a repair important date. Most states give you 30 to 60 days to have the vehicle repaired and retested. During this period, you can usually still drive the vehicle, though some states issue a "repair and retest" notice that you must carry.

If you do not retest within the important date, your registration will expire and you cannot legally drive the vehicle. Some states allow you to request an extension if you can show that you have taken the vehicle to a repair shop and are waiting for parts or service. A few states have hardship exemptions for low-income drivers, though these are uncommon and usually require documentation.

If your vehicle fails a second time after repairs, you may be required to take it to a state-certified repair facility or a dealership rather than an independent shop. Some states also have a "waiver" program that allows you to register the vehicle anyway if you have spent a certain amount on repairs (often $500 to $1,000) without passing — but this is not automatic and must be requested through your state's program.

Testing costs and where to get tested

Testing costs between $20 and $75 depending on your state and the type of vehicle. Most states charge a flat fee; a few charge more for diesel or heavier vehicles. The test itself takes 10 to 30 minutes and involves driving your vehicle on a dynamometer (a machine that measures emissions) or having a probe inserted into your exhaust pipe while the engine runs through a standard cycle.

You can find testing stations through your state's air quality or DMV website, which usually has a searchable map or list of certified facilities. Testing stations include independent repair shops, dealerships, and dedicated emissions testing centers. You do not have to go to a dealership — any certified station will do, and independent shops are often cheaper.

Some states allow you to get a waiver or extension if no testing stations are available within a certain distance of your home, though this is rare. If you live in a rural area of a state that requires testing, you may need to drive to the nearest city to find a testing station.

States with special programs for older or low-income vehicles

A few states have created programs to help drivers whose vehicles repeatedly fail emissions tests. California's Smog Check program includes a "gross polluter" category for vehicles that fail multiple times; these vehicles may be required to undergo more intensive repairs or be taken off the road. California also has a vehicle retirement program that pays low-income drivers to scrap vehicles that cannot pass.

Some states offer repair cost information or rebates for drivers who need to fix emissions-related problems. These programs are usually limited to low-income households and are administered through local air quality agencies or nonprofits. You can ask your testing station or state air quality office whether such a program exists in your area.

A few states also allow temporary registration renewals without a passing test if you can show that you have scheduled a repair appointment. This is not a waiver — you still must pass eventually — but it prevents your registration from expiring while you wait for service.

Frequently Asked Questions

Do I need emissions testing if I just bought a used car in a state that requires it?

Not when ready. Most states allow you 30 to 60 days from the purchase date to get the vehicle tested before you can renew your registration. Some states require the test before you can register it for the first time in that state. Check your state's DMV website or call your local office to confirm the timeline.

What if I move to a state that requires testing but my vehicle is registered in a state that does not?

You must re-register your vehicle in your new state within a set period (usually 30 to 90 days). When you do, you will need to pass an emissions test if your new state requires it. Some states will not issue a registration without proof of a passing test.

Can I drive my vehicle while waiting for a retest after it fails?

Yes, in most states. You have 30 to 60 days to repair and retest, and you can drive during that time. Some states issue a "repair and retest" notice that you should carry in your vehicle. If you do not retest by the important date, your registration expires and you cannot legally drive it.

What if my state requires testing but I cannot afford to repair my vehicle?

Some states have hardship programs or repair cost information for low-income drivers, though these are not common. Ask your state's air quality office or the testing station whether such a program exists. You can also request an extension if you can show that you have scheduled repairs but are waiting for parts or service.

Do electric vehicles need emissions testing?

No. Electric vehicles produce zero tailpipe emissions and are exempt from testing in all states that require it. Hybrid vehicles are usually tested under the same standards as gasoline vehicles, though some states have separate testing protocols for them.