Emissions tests are becoming increasingly common throughout the U.S. Obviously, cars produce air pollution when they burn fuel, so the U.S. Environmental Protection Agency enforces smog checks and emissions testing. Such is to ensure that road-going vehicles meet air quality standards to promote a healthier atmosphere.

The owner must repair or replace parts if vehicles fail to meet emissions standards. States and localities will ban failing cars from being driven on the road. Given the U.S. is a big place, nearly every state has different rules and regulations regarding emissions. So, what are they?

Which states require annual emissions tests?

Massachusetts: Passenger vehicles less than 15 years old.

New Hampshire: Registered vehicles under 20 years old.

New York: Passenger cars and light trucks built since 1996.

Vermont: Passenger cars 16 years old or newer.

Which states require biennial emissions tests?

Connecticut: All registered passenger cars.

Delaware: All vehicles at least five years old and made since 1967.

Rhode Island: All registered vehicles.

Which states only have certain localities that require emissions tests?

Arizona: All vehicles registered in Phoenix and Tucson.

Colorado: Most vehicles less than eight years old in larger counties like Denver, Broomfield, Douglas, and Boulder.

District of Columbia: All registered passenger vehicles.

Georgia: All vehicles in metropolitan Atlanta made after 1997 but under 25 years old.

Idaho: All vehicles registered in Ada and Canyon counties.

Illinois: All passenger vehicles at least four years old and made after 1996. such is true in the Chicago and East St. Louis metropolitan areas, according to the Illinois Environmental Protection Agency.

Indiana: All passenger vehicles made after 1975 in Lake and Porter counties, per the Indiana Bureau of Motor Vehicles.

Louisiana: Gasoline-powered passenger vehicles made after 1996 in East Baton Rouge, Iberville, Livingston, and West Baton Rouge, according to the Louisiana Department of Motor Vehicles.

Maine: All passenger vehicles made after 1996—with some exceptions—registered in Cumberland County, the Maine Department of Motor Vehicles says.

Maryland: All gasoline-only vehicles built after 1976 in Anne Arundel, Baltimore, Carroll, Calvert, Cecil, Charles, Fredrick, Howard, Hartford, Montgomery, Prince George’s, Queen Anne’s, and Washington counties. The Maryland Department of Motor Vehicles also includes hybrid cars at least three years old.

Missouri: All passenger cars made after 1997 in the St. Louis metropolitan area.

Nevada: Any vehicle made after 1968 in Clark and Washoe counties.

New Mexico: All vehicles registered in Bernalillo County built after 1987.

Ohio: All passenger cars built after 1996 in the counties surrounding Cleveland.

Oregon: All registered vehicles built after 1975 but at least four years old in Portland. In Medford, all cars less than 20 years old.  

Pennsylvania: All gasoline-powered passenger vehicles built after 1975 in most metropolitan counties.

Utah: All passenger cars less than six years old in Cache, Davis, Salt Lake, Utah, and Weber counties.

Texas: All gasoline-powered vehicles less than 25 years old in at least 17 metropolitan area counties.

Virginia: All registered passenger vehicles in the counties surrounding Washington, D.C.

Wisconsin: All gasoline-powered passenger cars built after 1996 in Kenosha, Milwaukee, Ozaukee, Racine, Sheboygan, Washington, and Waukesha counties.

What about California?

California enforces some of the strictest emissions testing requirements in the country. The part of the state you live in will determine what tests are needed, per the California Department of Motor Vehicles.

All gasoline-powered vehicles made after 1975 and all diesel-powered vehicles produced after 1997 must be checked. But for the first eight years of a car’s life, owners must pay a smog abatement fee instead of testing.

How do you get your vehicle checked for emissions standards?  

Depending on the state or locality, emissions tests can be done in various ways. Often, mechanic shops can conduct the tests in many states. However, others provide even quicker avenues.

Kelley Blue Book reports that Virginia has an inspection program called Rapidpass. Motorists can drive through the system, completing their emissions test in less than a second without visiting a testing station. Washington, D.C., Maryland, and a few other states have self-service kiosks where drivers can go.