asset: vehicle-emissions-testing-by-state

asset_type: jurisdictional-variation

body: For each US state that runs a vehicle emissions inspection (I/M) program: which counties require testing, how often, which vehicles are exempt, and the test type — from the state environmental agency's own page, not a DMV content mill. The answer is county-level, not state-level, and it is moving: North Carolina asked EPA to remove all nineteen of its remaining counties (submitted October 2024), Texas is adding Bexar County (San Antonio) in 2026, and Colorado is changing test types in 2026. Georgia's program covers exactly 13 named metro-Atlanta counties; Texas covers 17 counties across four metros; Colorado covers all or part of 9 Front Range counties. EPA maintains no current state/county list — only technical guidance. Answers 'do I need an emissions test to register my car in [county], [state]', 'is [state] getting rid of emissions testing', and 'how old does my car have to be to be exempt in [state]'. States with no program get no record unless their agency states the absence.

key_field: jurisdiction

licence: unknown

title: Vehicle emissions testing: which counties require it, in which states

type: dataset


body:
**State:** Arizona

**Counties where testing is required:** the Phoenix and Tucson metropolitan areas

> Vehicle emissions testing is required in major metropolitan areas that are not meeting federal air quality standards for ozone and other pollutants. In Arizona, testing is required in the Phoenix and Tucson metropolitan areas, where ozone and particulate matter pollution are a problem.

Source: <https://www.myazcar.com/>

jurisdiction: Arizona

title: Arizona — Vehicle emissions testing: which counties require it, in which states

type: jurisdictional-variation


body:
**State:** Colorado

**Counties where testing is required:** all or portions of Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer, and Weld counties

**Vehicles covered / exempt:** owners of gasoline-powered vehicles in the Front Range area of Colorado

**Recent or pending change:** Starting in 2026, these Colorado drivers will have access to self-service kiosks for On-Board Diagnostics (OBD) emissions tests that will be available 24/7 at convenient locations

**Program / authority:** Automobile Inspection and Readjustment (AIR) program

> The commission approved of updates to Regulation 11, which applies to owners of gasoline-powered vehicles in the Front Range area of Colorado. This area includes all or portions of Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer, and Weld counties. Starting in 2026, these Colorado drivers will have access to self-service kiosks for On-Board Diagnostics (OBD) emissions tests that will be available 24/7 at convenient locations.

Source: <https://cdphe.colorado.gov/apcd/motor-vehicle-emissions>

jurisdiction: Colorado

title: Colorado — Vehicle emissions testing: which counties require it, in which states


body:
**State:** Georgia

**How often:** tested every year prior to its registration date (the vehicle owner’s birthday)

**Vehicles covered / exempt:** For registration in 2026, the three most recent model years are exempt from emissions testing, which includes 2024 or newer model year vehicles

**Program / authority:** Georgia's Clean Air Force

> Your vehicle must be tested every year prior to its registration date (the vehicle owner’s birthday). For registration in 2026, the three most recent model years are exempt from emissions testing, which includes 2024 or newer model year vehicles.

Source: <https://cleanairforce.com/frequently-asked-questions>

jurisdiction: Georgia

program_name: Georgia's Clean Air Force

title: Georgia — Vehicle emissions testing: which counties require it, in which states


body:
**State:** Georgia

**Counties where testing is required:** 13-county Atlanta Metropolitan Area (Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding or Rockdale)

**Vehicles covered / exempt:** gasoline-powered passenger vehicles registered in the 13-county Atlanta Metropolitan Area

**Program / authority:** Georgia’s Clean Air Force

> Georgia has a vehicle emissions testing program that covers gasoline-powered passenger vehicles registered in the 13-county Atlanta Metropolitan Area (Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding or Rockdale). The program is required by the Clean Air Act and administered by our Inspection and Maintenance (I/M) unit.

Source: <https://epd.georgia.gov/air-protection-branch/air-branch-programs/mobile-and-area-sources-program/inspection-and>

program_name: Georgia’s Clean Air Force


body:
**State:** Illinois

**How often:** even model-year vehicles are inspected during even years, and odd model-year vehicles are inspected in odd years

**Vehicles covered / exempt:** Most 1996 and newer gasoline-powered passenger vehicles are subject to emissions inspections after they are four years old

**Program / authority:** vehicle emissions inspection program

> Most 1996 and newer gasoline-powered passenger vehicles are subject to emissions inspections after they are four years old (e.g. 2012 vehicles are being inspected in 2016 for the first time). The inspection month coincides with the expiration date of the vehicle license plate. Typically, even model-year vehicles are inspected during even years, and odd model-year vehicles are inspected in odd years.

Source: <https://epa.illinois.gov/topics/air-quality/mobile-sources/vehicle-emissions-testing.html>

jurisdiction: Illinois

program_name: vehicle emissions inspection program

title: Illinois — Vehicle emissions testing: which counties require it, in which states


body:
**State:** Illinois

**Counties where testing is required:** these areas of Illinois

**Program / authority:** vehicle emissions inspection program

> Additionally, the Illinois Vehicle Emissions Inspection Law of 2005 (625 ILCS 5/13C) requires a vehicle emissions inspection program to reduce air pollution from motor vehicles in these areas of Illinois. For these reasons, the vehicle emissions inspection program is part of Illinois EPA’s strategy to reduce air pollution in Illinois and bring the Chicago and Metro-East areas into attainment of the ozone NAAQS.

Source: <https://epa.illinois.gov/topics/air-quality/mobile-sources/vehicle-emissions-testing.html>

counties_covered: these areas of Illinois


body:
**State:** Nevada

**Counties where testing is required:** the urban areas of Clark or Washoe county

**How often:** emission tests each year for qualifying vehicles

**Vehicles covered / exempt:** Gasoline powered (regardless of weight or size)

**Program / authority:** Nevada Emission Control Program

> Nevada requires emission tests each year for qualifying vehicles Your Vehicle Needs a Test if it is: Location Based Based in the urban areas of Clark or Washoe county. Model Year 1968 model year or newer. Vehicle Type Gasoline powered (regardless of weight or size)

Source: <https://dmv.nv.gov/emission.htm>

jurisdiction: Nevada

program_name: Nevada Emission Control Program

title: Nevada — Vehicle emissions testing: which counties require it, in which states


body:
**State:** North Carolina

**Counties where testing is required:** 19 counties

**How often:** emission systems tests for cars and light-duty trucks as part of the annual safety inspection in 19 counties

**Vehicles covered / exempt:** cars and light-duty trucks

**Recent or pending change:** Section 12.7 of Session Law (S.L.) 2023-134 (House Bill 259) of the 2023 session of the North Carolina General Assembly, passed into law October 3, 2023, will remove 18 counties from the I&M program. Section 12.13.(b) of Session Law (S.L.) 2026-41 (Senate Bill 257) of the 2026 session of the North Carolina General Assembly, passed into law July 7, 2026, will also remove Mecklenburg County from the program.

**Program / authority:** Inspection / Maintenance (I/M) Program

> North Carolina requires emission systems tests for cars and light-duty trucks as part of the annual safety inspection in 19 counties. Vehicles from 1996 and newer are usually equipped with On-Board Diagnostic (OBD) systems, which help inspectors check that the vehicle's pollution controls are working. <https://deq.nc.gov/about/divisions/air-quality/motor-vehicles-air-quality/inspection-maintenance-program/emissions-inspection-results-information> Emissions Testing FAQ <https://www.deq.nc.gov/mitigation-services/publicfolder/library/news/brochures/doudrive1996ornewercar/download> Do you drive a 1996 or newer car or light truck? <https://deq.nc.gov/about/divisions/air-quality/motor-vehicles-and-air-quality/smoking-vehicle-complaint-form> Smoking Vehicle Complaint Form Update: Inspection & Maintenance Program Set to End Statewide Recent changes to state law may soon terminate the vehicle Inspection & Maintenance (I&M) Program in the 19 counties that are currently subject to the program. Section 12.7 of Session Law (S.L.) 2023-134 (House Bill 259) of the 2023 session of the North Carolina General Assembly, passed into law October 3, 2023, will remove 18 counties from the I&M program. Section 12.13.(b) of Session Law (S.L.) 2026-41 (Senate Bill 257) of the 2026 session of the North Carolina General Assembly, passed into law July 7, 2026, will also remove Mecklenburg County from the program.

Source: <https://deq.nc.gov/about/divisions/air-quality/motor-vehicles-air-quality/inspection-maintenance-program>

counties_covered: 19 counties

jurisdiction: North Carolina

program_name: Inspection / Maintenance (I/M) Program

title: North Carolina — Vehicle emissions testing: which counties require it, in which states

vehicle_scope: cars and light-duty trucks


body:
**State:** Texas

**Counties where testing is required:** 15 counties in the Dallas-Fort Worth, Houston-Galveston-Brazoria, and El Paso nonattainment areas, and in Travis and Williamson Counties in the Austin-Round Rock area

**How often:** annual inspection of gasoline-powered vehicles 2–24 years old

**Vehicles covered / exempt:** gasoline-powered vehicles 2–24 years old

**Program / authority:** Vehicle Inspection and Maintenance (I/M) Program

> Texas first established a vehicle emissions testing program on January 1, 1995, meeting the U.S. Environmental Protection Agency's requirements for I/M programs. The <https://www.tceq.texas.gov/airquality/mobilesource/vim/overview.html> I/M program has been implemented in 15 counties in the Dallas-Fort Worth, Houston-Galveston-Brazoria, and El Paso nonattainment areas, and in Travis and Williamson Counties in the Austin-Round Rock area. The I/M program requires the annual inspection of gasoline-powered vehicles 2–24 years old in the affected counties. Vehicles must be inspected through Department of Public Safety–certified inspection stations for emissions of NO X , VOC, and CO.

Source: <https://www.tceq.texas.gov/airquality/mobilesource/im.html>

jurisdiction: Texas

title: Texas — Vehicle emissions testing: which counties require it, in which states


body:
**State:** Texas

**Counties where testing is required:** Brazoria, Collin, Dallas, Denton, Ellis, El Paso, Fort Bend, Galveston, Harris, Johnson, Kaufman, Montgomery, Parker, Rockwall, Tarrant, Travis, and Williamson Counties

**How often:** annual emissions inspection

**Recent or pending change:** Beginning November 1, 2026, motorists with vehicles registered in Bexar County will not be eligible to renew their vehicle's annual registration if the vehicle has not passed its annual emissions inspection

**Program / authority:** vehicle emissions inspection program

> Motorists with vehicles registered in Brazoria, Collin, Dallas, Denton, Ellis, El Paso, Fort Bend, Galveston, Harris, Johnson, Kaufman, Montgomery, Parker, Rockwall, Tarrant, Travis, and Williamson Counties will not be eligible to renew their vehicle's annual registration if the vehicle has not passed its annual emissions inspection or complied with the vehicle emissions inspection program requirements. Beginning November 1, 2026, motorists with vehicles registered in Bexar County will not be eligible to renew their vehicle's annual registration if the vehicle has not passed its annual emissions inspection or complied with the vehicle emissions inspection program requirements.

Source: <https://www.tceq.texas.gov/airquality/mobilesource/vim/overview.html>

test_frequency: annual emissions inspection


body:
**State:** Washington

**Recent or pending change:** Washington's vehicle emission check program ended Jan. 1, 2020

**Program / authority:** vehicle emission check program

> After 38 years, Washington's vehicle emission check program ended Jan. 1, 2020. An emission test is no longer required before renewing your vehicle registration.

Source: <https://ecology.wa.gov/Air-Climate/Air-quality/Vehicle-emissions>

jurisdiction: Washington

program_name: vehicle emission check program

title: Washington — Vehicle emissions testing: which counties require it, in which states