Emissions Test Requirements by State

Each state sets its own emissions test requirements, and many test only in named counties. Find your state in the table: where the test applies, which test, how often and the state fee.

27 + D.C.: states, plus Washington, D.C., that test car emissions
20: of them test only in named counties or metro areas
7: states that ended or paused testing
16: states that have no current program

Test type, test frequency and state fee in each state

State	Where it applies	Test	How often	State fee	New cars	Diesels	Official source
Alabama	No current program	No emissions test					revenue.alabama.gov
Alaska	Ended in 2012	No emissions test					dec.alaska.gov
Arizona	Phoenix metropolitan area, Tucson metropolitan area	OBD, tailpipe, diesel smoke	Every 2 years for 1981 and newer cars; every year for 1980 and older cars and most Tucson-area cars	Varies by test and area	The 5 newest model years are exempt	Yes	azdot.gov
Arkansas	No current program	No emissions test					Colorado DMV list of states with no test
California	34 counties	OBD, tailpipe, visual	Every 2 years at registration renewal, and when the car is sold or first registered in California	Set by the station, plus an $8.25 certificate fee	The 8 newest model years skip the renewal test (a smog abatement fee is paid instead); diesels have no new-car exemption	Yes	dmv.ca.gov
Colorado	9 counties	OBD, tailpipe, gas cap	Every 2 years for 1982 and newer cars; every year for 1981 and older cars	$35, or $20 for 1981 and older cars	The 7 newest model years are exempt (4 for diesels)	Yes	dmv.colorado.gov
Connecticut	Whole state	OBD	Every 2 years	$20	Cars younger than 4 model years are exempt	Yes	portal.ct.gov
Delaware	Whole state	OBD, tailpipe	Every 2 years	Free	The 7 newest model years are exempt	Yes	dnrec.delaware.gov
Florida	Ended in 2000	No emissions test					Colorado DMV list of states with no test
Georgia	13 counties	OBD, visual	Every year, before your registration renewal	Set by the station, up to $25	The 3 newest model years are exempt	No	dekalbtaxga.gov
Hawaii	No current program	No emissions test					Colorado DMV list of states with no test
Idaho	Ended in 2023	No emissions test					www2.deq.idaho.gov
Illinois	Chicago area, Metro-East St. Louis area	OBD	Every 2 years: even model years in even years, odd model years in odd years, in your plate's expiration month	Free	The 4 newest model years are exempt	No	epa.illinois.gov
Indiana	Lake County, Porter County	emissions test, tampering check	Every 2 years: odd model years in odd years, even model years in even years	Free at Clean Air Car Check stations	The 4 newest model years are exempt	No	in.gov
Iowa	No current program	No emissions test					Colorado DMV list of states with no test
Kansas	No current program	No emissions test					ksrevenue.gov
Kentucky	Ended in 2005	No emissions test					epa.gov
Louisiana	5 parishes	OBD, tampering check, gas cap	Every year, with the safety inspection	$18 (state set, includes the $10 safety inspection)		No	deq.louisiana.gov
Maine	Cumberland County	OBD, gas cap	Every year, with the state safety inspection	Part of the yearly state inspection fee		No	maine.gov
Maryland	14 counties	OBD, tailpipe, gas cap, tampering check	Every 2 years	$30 at a station, $26 at a self-serve kiosk	New cars are exempt for their first 72 months (6 years) with the first owner	No	mva.maryland.gov
Massachusetts	Whole state	OBD, diesel smoke	Every year, with the safety inspection	$35 (state set, combined safety and emissions inspection)	New cars need their first inspection soon after registration	Yes	mass.gov
Michigan	No current program	No emissions test					Colorado DMV list of states with no test
Minnesota	No current program	No emissions test					house.mn.gov
Mississippi	No current program	No emissions test					dor.ms.gov
Missouri	4 areas	OBD	Every 2 years (odd model years in odd years, even in even years), and when the car is sold	Set by the station, up to $24	New cars are exempt for their model year and the next year if under 6,000 miles at first sale	Yes	gatewayvip.mo.gov
Montana	No current program	No emissions test					Colorado DMV list of states with no test
Nebraska	No current program	No emissions test					Colorado DMV list of states with no test
Nevada	Clark County (Las Vegas urban area), Washoe County (Reno urban area)	OBD, tailpipe	Every year	Set by the station, with a different cap in each county	New cars skip the test for their first three registrations; hybrids for their first five model years	Yes	dmv.nv.gov
New Hampshire	Paused	No emissions test					dmv.nh.gov
New Jersey	Whole state	OBD, emission parts check	Every 2 years (you may test up to two months early)	Free at state stations; private stations set their own	New cars get a 5-year sticker	Yes	nj.gov
New Mexico	Bernalillo County	OBD, tailpipe, gas cap	Every 2 years, and when the car is sold	Set by the station	New cars are exempt for 4 years with the first owner	No	mvd.newmexico.gov
New York	Whole state	OBD, gas cap, emission parts check	Every year, with the safety inspection	Varies by area: up to $27 near New York City, $11 elsewhere	Cars less than 2 model years old are exempt	Yes	dmv.ny.gov
North Carolina	19 counties	OBD	Every year, with the safety inspection	Set by the station, up to $30 with the safety inspection	The 3 newest model years with under 70,000 miles are exempt	No	ncdot.gov
North Dakota	No current program	No emissions test					Colorado DMV list of states with no test
Ohio	7 counties	OBD	Every 2 years: even model years in even years, odd model years in odd years	Free for up to 3 tests in 365 days	The 6 newest model years are exempt (7 for non-plug-in hybrids)	Yes	epa.ohio.gov
Oklahoma	No current program	No emissions test					Colorado DMV list of states with no test
Oregon	Portland Metro, Medford/Ashland	OBD, tailpipe	Every 2 years, before registration renewal	Varies by area: $25 Portland, $20 Medford	The 4 newest model years are exempt	Yes	oregon.gov
Pennsylvania	25 counties	OBD, gas cap, visual	Every year, with or before the safety inspection	Set by the station	A brand-new car of the current model year under 5,000 miles is exempt	No	pa.gov
Rhode Island	Whole state	combined safety and emissions test	Every 2 years	$55 (state set, combined safety and emissions test)	New cars are exempt for 2 years or 24,000 miles, whichever comes first	Yes	dmv.ri.gov
South Carolina	No current program	No emissions test					Colorado DMV list of states with no test
South Dakota	No current program	No emissions test					Colorado DMV list of states with no test
Tennessee	Ended in 2022	No emissions test					nashville.gov
Texas	18 counties	OBD	Every year, before registration renewal	Varies by county: up to $18.50 or $11.50	Cars are tested from their second anniversary	No	dps.texas.gov
Utah	5 counties	OBD	Every 2 years while a car is under 6 years old (even model years in even years), then every year; every 2 years in Cache County	Set by the station	The 2 newest model years are exempt	Yes	tax.utah.gov
Vermont	Whole state	OBD, gas cap, visual	Every year, with the safety inspection	Set by the station		Yes	dec.vermont.gov
Virginia	10 areas	station test or roadside remote sensing	Every 2 years	Set by the station, up to $28, plus $2 at registration	The 4 newest model years are exempt	Yes	dmv.virginia.gov
Washington	Ended in 2020	No emissions test					ecology.wa.gov
Washington, D.C.	Whole state	OBD, tailpipe	Every 2 years for personal cars; every year for commercial and for-hire vehicles	$35 (state set, every 2 years with the registration)	New cars get a 4-year sticker	No	dmv.dc.gov
West Virginia	No current program	No emissions test					Colorado DMV list of states with no test
Wisconsin	7 counties	OBD	Every 2 years before registration renewal, and when the car changes owner	Free	The 3 newest model years are exempt at renewal	Yes	wisconsindot.gov
Wyoming	No current program	No emissions test					Colorado DMV list of states with no test

Download the table: emissions-test-requirements-by-state.csv (51 rows, one per state plus D.C.). Every row links a government page: the state's own inspection or environmental agency where it runs a program, and for most states with no program, the Colorado DMV's list of states that do not test. The compilation is free to reuse under CC BY 4.0; a credit such as "State emissions program table from emissions-test.com (CC BY 4.0), compiled from each state's inspection agency" is enough.

States that require emissions testing

Whole state Named counties or metro areas Ended or paused No current program

How this table is made

Each cell comes from the state agency page linked in its row. The fee is the amount the state sets or caps, not a quote from a station; what a test costs in practice is on emissions test cost by state. A blank cell means the agency publishes no figure, and "no current program" does not claim the state never tested cars.

Which cars skip the test is on emissions test exemptions, and how diesels are tested is on the diesel emissions test page. For the plug-in test's self-checks, see readiness monitors not ready; the CSV adds the monitor rule for the states that publish their own number.