States That Require Emissions Testing

Thirty-five states and the District of Columbia require some form of vehicle emissions testing, but the rules vary widely by location. Some states test all vehicles; others test only those in certain counties or metropolitan areas. A few states have no emissions testing requirement at all. Your state's requirement depends on where you live and, in some cases, which county you live in.

The states with the broadest emissions testing programs are California, New York, Massachusetts, Connecticut, Delaware, Maine, Maryland, New Jersey, New Hampshire, Rhode Island, Vermont, and Washington. These states typically require testing for all or nearly all registered vehicles. The remaining states with emissions programs—including Colorado, Georgia, Illinois, Indiana, Kentucky, Louisiana, Michigan, Minnesota, Missouri, Nevada, New Mexico, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Virginia, and Wisconsin—require testing only in specific regions, usually around major cities or areas that do not meet federal air quality standards.

Ten states have no emissions testing requirement: Alabama, Alaska, Arkansas, Hawaii, Iowa, Kansas, Mississippi, Missouri (outside certain areas), Montana, South Carolina, South Dakota, West Virginia, and Wyoming. Even in these states, your vehicle must still pass a safety inspection if your state requires one, but emissions testing is not part of that process.

Key Takeaways

  • Thirty-five states and Washington, D.C. require emissions testing, but most limit it to specific counties or regions rather than statewide.
  • California, New York, and the Northeast states test nearly all vehicles, while states like Texas and Colorado test only in areas that fail federal air quality standards.
  • Ten states have no emissions testing requirement at all, though they may still require safety inspections.
  • Your county or metropolitan area determines whether you must test, not your state alone, so check your local DMV or emissions program website.
  • Testing frequency ranges from every two years to every other year, depending on your vehicle's age and your state's rules.

How to learn about Your State Tests Emissions

The fastest way to learn whether your state requires emissions testing is to visit your state's Department of Motor Vehicles website and search for "emissions testing" or "vehicle inspection." Most state DMV sites have a section that lists which counties or regions require testing and what the testing schedule is. If your state has a separate emissions program office—some do—that office's website will have the same information, often with more detail about test locations and what happens if you fail.

If you cannot find the answer on your state's DMV site, call your county's DMV office directly. They can tell you in one call whether testing is required where you live, when your vehicle is due for testing, and where you can have it done. Keep your vehicle registration handy when you call, because they may ask for your vehicle identification number (VIN) or registration number to check your testing history.

You can also search online for "[your state] emissions testing requirements" or "[your county] vehicle emissions program." This usually brings up the official program page, which lists test locations, fees, and what to do if your vehicle fails.

States With Regional or County-Based Testing

Many states require emissions testing only in counties or regions that the federal Environmental Protection Agency (EPA) has designated as not meeting air quality standards. These areas are usually around major cities like Houston, Denver, Atlanta, and Chicago. If you live in a county that does not meet these standards, you must test; if you live in a county that does, you do not.

Texas is a common example. The state does not require emissions testing statewide, but it does require testing in the Houston, Dallas-Fort Worth, and Austin areas. Colorado requires testing in the Denver metropolitan area and a few other regions. Georgia requires testing in the Atlanta area. If you move within your state, your testing requirement may change depending on which county you move to.

The EPA updates its air quality designations periodically, so a county that did not require testing in the past may begin requiring it, or vice versa. Check your state's emissions program website annually to confirm your county's status, especially if you live near the boundary of a testing area.

Testing Frequency and Vehicle Age

States that require emissions testing typically test vehicles every two years, though some test every year. A few states exempt newer vehicles—often those fewer than four or five years old—from testing for their first few years of ownership. Some states also exempt vehicles over a certain age, usually 25 years or older, on the assumption that older vehicles are driven less frequently.

Your state's DMV or emissions program website will list the exact schedule for your vehicle. The testing requirement is usually tied to your vehicle registration renewal, so you will see it listed on your registration notice or renewal letter. If your vehicle is due for testing and you do not complete it before your registration expires, you may not be able to renew your registration.

Hybrid and electric vehicles are treated differently in some states. A few states exempt them from emissions testing entirely, while others test them on the same schedule as gasoline vehicles. Check your state's rules if you own an electric or hybrid vehicle.

What Happens If Your Vehicle Fails the Emissions Test

If your vehicle fails an emissions test, you have a set amount of time—usually 30 to 60 days—to have repairs made and retest. The specific timeframe is listed on your test results. You do not need to return to the same testing facility; you can go to any certified emissions testing location in your state.

Some states offer a waiver program if your vehicle fails and the repairs needed would cost more than a certain amount, often $300 to $500. If you may have access to for a waiver, you can register your vehicle without passing the test, though you may have to pay a waiver fee. Not all states have this program, so check your state's emissions website to see whether you are may be able to access.

If you fail the test a second time after repairs, you may be required to take your vehicle to a certified repair shop rather than a general testing facility. Some states also require you to document the repairs you had done before you can retest.

States With No Emissions Testing

If you live in Alabama, Alaska, Arkansas, Hawaii, Iowa, Kansas, Mississippi, Montana, South Carolina, South Dakota, West Virginia, or Wyoming, your state does not require emissions testing. You still need to register your vehicle and may need to pass a safety inspection, but you will not have to take an emissions test.

If you move to one of these states from a state that requires testing, you do not need to worry about your vehicle's emissions history. Your new state's registration process will not ask about it. However, if you move from one of these states to a state that does require testing, your vehicle will need to pass a test before you can register it in your new state.

Emissions Testing Fees and Where to Test

Emissions testing fees vary by state but typically range from $15 to $50 per test. Some states charge a flat fee; others charge different amounts depending on the vehicle type or age. Your state's DMV or emissions program website lists the current fee.

Testing is done at certified emissions testing facilities, which include many independent repair shops, chain automotive service centers, and dedicated emissions testing stations. Your state's emissions program website has a searchable list of certified locations near you. You can usually schedule an appointment online or by phone, though some facilities accept walk-ins.

The test itself takes 10 to 30 minutes. You drive your vehicle on a dynamometer (a machine that measures emissions while your vehicle is running) or, in some states, the tester connects a device to your vehicle's onboard diagnostic system to read emissions data. You will receive your results when ready, either as a pass, fail, or conditional pass.

Frequently Asked Questions

Do I need emissions testing if I just bought a used car?

It depends on your state and when your vehicle is due for testing. If you buy a used car and it is not yet due for testing, you do not need to test it when ready. However, you must test it before your registration expires or before the test is due, whichever comes first. Check your registration documents or your state's emissions website to find out when your vehicle is due.

What if I move to a different state—do I need to retest my vehicle?

If you move to a state that requires emissions testing and your vehicle has not been tested recently, you will need to have it tested before you can register it in your new state. If you move to a state with no emissions requirement, you do not need to test. Contact your new state's DMV to learn the specific requirements for registering an out-of-state vehicle.

Can I test my vehicle early, before it is due?

Yes, most states allow early testing. If you test early, your new test date will be calculated from the date of that early test, not from your original due date. This can be useful if you are planning to move or sell your vehicle soon. Check your state's rules to confirm.

What if my vehicle has a check engine light on—will it fail the test?

A check engine light does not automatically mean your vehicle will fail, but it may. The test measures actual emissions output. If the light is on because of an emissions-related problem, your vehicle will likely fail. If the light is on for a non-emissions reason, your vehicle may still pass. Have the code read before testing so you know what the problem is.

Do I have to test my vehicle if I do not drive it much?

Yes, if your state or county requires testing, you must test your vehicle to renew your registration, regardless of how often you drive it. Some states exempt vehicles that are registered as non-operational or off-road only, but standard passenger vehicle registration requires testing if your area has a testing program.