referencesource/vehicle-emissions-testing-by-state

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

Canonical, always-current version: https://referencesource.org/vehicle-emissions-testing-by-state/ Machine-readable: https://referencesource.org/vehicle-emissions-testing-by-state/data.json — this mirror is a point-in-time copy.

• Last verified: 2026-08-25
• Stale after: 2027-08-25 (past this date, prefer the canonical copy — it re-verifies on a cadence this snapshot does not)
• Records: 28

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; California's list of 34 counties is the fact that testing there is not statewide. Some exemptions move on their own: Virginia's regulation exempts anything older than 'the current calendar year minus 24', so the cut-off year advances every January whether or not anyone republishes the page; Vermont tests the OBD system on vehicles '16 model years old or newer', and New York's OBDII window runs from 'the current year minus 25' to 'the current year minus two' — three rolling cut-offs no static listicle tracks. The north-east answers the county question differently: Vermont, New Jersey, Rhode Island, Delaware and New Hampshire inspect everywhere in the state, and in New York the county list that matters is the Diesel Emissions Metropolitan Area for heavy diesels, while light diesels take the OBDII test anywhere in the state. EPA maintains no current state/county list — only technical guidance. Utah is the clearest case for asking the question county by county: its program is run by five county health departments and they do not share one rule, so Cache County exempts vehicles less than six model years old while Salt Lake, Davis, Weber and Utah counties test them every other year, and Utah County alone tests 1998–2021 diesels. New Mexico's whole program is one county — Bernalillo — under the Albuquerque-Bernalillo County Air Quality Control Board's own regulation. Two states are recorded here as stated absences rather than omitted: Idaho repealed the state I/M requirement effective 1 July 2023, and EPA removed Tennessee's six counties from the federally-approved plan effective 16 September 2021 — though that rule's own footnote says it does not preclude counties keeping a local program, so 'Tennessee has no testing' is not quite what the source says. Two gaps are stated rather than papered over. Ohio names no county anywhere we can reach: OAC 3745-26-01(G) defines the program area by nonattainment status instead of by name, so the cadence, the twenty-five-year scope, the exemptions and the E-Check contract's June 2027 end date are recorded and the county list is not claimed. And Massachusetts carries no cadence, because the annual interval lives in 540 CMR 4.00, which no host that will serve us publishes as text; its scope and exemptions come from Cornell LII's mirror of 310 CMR 60.02 — a mirror, not mass.gov, which blocks us, and one that states it reflects amendments only through 11 August 2017. 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.

Provenance — what every record carries

Every record carries source (the URL the value was read from) and source_quote (a verbatim quote from that page stating it). A value you cannot check against its page is indistinguishable from an invented one; these can all be checked. Each record is also individually addressable on the canonical site at its url.

Licence position

unknown

Facts are not copyrightable; what this dataset takes from each source is a fact plus a short attributed quote linking back to the page that states it.

Sources

• https://www.myazcar.com/
• https://www.bar.ca.gov/consumer/smog-check-program
• https://www.dmv.ca.gov/portal/vehicle-registration/smog-inspections/
• https://cdphe.colorado.gov/apcd/motor-vehicle-emissions
• https://www.ctemissions.com/types-of-vehicle-testing
• https://www.ctemissions.com/
• https://dnrec.delaware.gov/air/mobile-sources/inspection-maintenance/
• https://cleanairforce.com/frequently-asked-questions
• https://epd.georgia.gov/air-protection-branch/air-branch-programs/mobile-and-area-sources-program/inspection-and
• https://www.deq.idaho.gov/air-quality/vehicle-emissions/
• https://epa.illinois.gov/topics/air-quality/mobile-sources/vehicle-emissions-testing.html
• https://mva.maryland.gov/vehicles/Pages/VEIP.aspx
• https://www.law.cornell.edu/regulations/massachusetts/310-CMR-60-02
• https://gatewayvip.mo.gov/need-test/
• https://dmv.nv.gov/emission.htm
• https://www.gencourt.state.nh.us/rules/state_agencies/saf-c3200.html
• https://www.nj.gov/mvc/inspection/exemptinsp.htm
• https://www.nj.gov/mvc/inspection/aboutinsp.htm
• https://www.srca.nm.gov/parts/title20/20.011.0100.html
• https://dmvsearch.webnycdn.ny.gov/node/5906
• https://deq.nc.gov/about/divisions/air-quality/motor-vehicles-air-quality/inspection-maintenance-program
• https://codes.ohio.gov/ohio-revised-code/section-3704.14
• https://codes.ohio.gov/ohio-administrative-code/rule-3745-26-12
• https://www.oregon.gov/deq/Vehicle-Inspection/Pages/About-the-program.aspx
• https://www.pacodeandbulletin.gov/Display/pacode?file=/secure/pacode/data/067/chapter177/s177.51.html
• https://www.pacodeandbulletin.gov/Display/pacode?file=/secure/pacode/data/067/chapter177/s177.3.html
• https://rules.sos.ri.gov/regulations/part/280-30-15-1
• https://www.federalregister.gov/documents/2021/08/17/2021-17214/air-plan-approval-tn-removal-of-vehicle-im-program-for-the-middle-tennessee-and-hamilton-county
• https://www.tceq.texas.gov/airquality/mobilesource/im.html
• https://www.tceq.texas.gov/airquality/mobilesource/vim/overview.html
• https://dmv.utah.gov/register/inspections/
• https://dec.vermont.gov/air-quality/mobile-sources/vehicle-emissions-inspections
• https://law.lis.virginia.gov/admincode/title9/agency5/chapter91/section20/
• https://ecology.wa.gov/Air-Climate/Air-quality/Vehicle-emissions
• https://www.wisconsinvip2.org/Content/FAQ
• https://dnr.wisconsin.gov/topic/AirQuality/Mobile.html

Fields

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