Vehicle emissions and smog testing, state by state

Do I need an emissions test?

Choose a state and enter the vehicle’s details. The checker shows the official wording we hold for that state, quote by quote, and where your model year and weight fall against the figures printed in it. It does not decide anything for you; the agency does.

• 28states and districts where we could quote an official text describing a testing program
• 8where an official text says a program ended or was repealed, or says the state requires no emissions test
• 15where we found no settled official statement, and say so
• 522quotes, each matched word for word to its source on November 11, 2026

Which states can I look up?

These are the 28 places where an official source we could read describes a vehicle emissions testing program, each with the name its text uses. Each page carries that place’s own quotes: the name the text uses and where the program applies, and, where we could quote them, how often, the fee, and the wording on new, older, diesel, electric and heavier vehicles. Where we could not quote a subject, the page says so.

• Arizonaemissions inspection program
• CaliforniaSmog Check
• ColoradoAir Care Colorado
• ConnecticutConnecticut Emissions Program
• DelawareVehicle Inspection and Maintenance (I/M) program
• District of ColumbiaDC DMV inspection
• GeorgiaGeorgia's Clean Air Force
• IllinoisIllinois Air Team
• IndianaClean Air Car Check
• LouisianaInspection and Maintenance (I/M) program
• Maineenhanced inspection
• MarylandVehicle Emissions Inspection Program (VEIP)
• MassachusettsEmissions inspection and maintenance program
• MissouriGateway Vehicle Inspection Program
• NevadaNevada Emission Control Program
• New JerseyVehicle Inspections
• New MexicoAir Care
• New YorkNYVIP
• North CarolinaInspection/Maintenance (I/M) Program
• OhioE-Check
• OregonVehicle Inspection Program
• PennsylvaniaDrive Clean PA
• Rhode IslandRhode Island Motor Vehicle Inspection/Maintenance Program
• Texasvehicle inspection and maintenance (I/M) program
• Utahemissions inspection
• VermontVehicle Emissions Inspection and Maintenance Program
• Virginiaemissions inspection program
• WisconsinWisconsin Vehicle Inspection Program

The other 23 are on one page, states that are not in the checker, sorted by what official text does and does not say. The comparison table puts all 51 side by side.

Why do some places test and others don’t?

The US Environmental Protection Agency describes the programs this way:

Vehicle inspection and maintenance, or I/M, is the periodic inspection of the emissions control systems of motor vehicles.

Vehicle inspection and maintenance (I/M) programs help improve air quality by identifying cars and trucks with high emissions and that may need repairs.

The 1990 Amendments to the Clean Air Act (CAA) mandated I/M for ozone and carbon monoxide (CO) nonattainment areas based upon certain criteria, such as air quality status, population, and/or geographic location.

The CAA established two performance levels of I/M programs: "Basic" and "Enhanced" I/M.

Basic I/M programs are for ozone nonattainment areas classified as Moderate with an urbanized population over 200,000 in 1990 and only require testing for light-duty cars.

Both light-duty cars and trucks must be inspected in Enhanced I/M areas.

Beginning with the 1996 model year, vehicles have been equipped with OBD computerized systems.

States are responsible for developing their own I/M program to meet EPA's I/M regulations (40 CFR part 51, subpart S), and vehicle testing requirements vary across the country.

How should I read a result?

Each result is a quote and, where the quote prints a figure the checker can compare, a plain comparison: the number you entered is below it, equal to it or above it. It stops there. Where a quote counts something a model year can’t give, the checker shows the quote and makes no comparison. A missing quote is a gap in what we could read, not a statement about the rule. How it works has the detail, the pages we could not read and how to send a correction.