Emissions Test by State

Do I need an emissions test?

Pick your state, county and car. You get a yes or a no, the reason in plain English, and the official text that proves it.

Emissions testing, state by state

Tap a state for its rules. A hatched square is a state where we found no official statement either way, which is not the same as no rule.

  1. AL
  2. AK
  3. AZ
  4. AR
  5. CA
  6. CO
  7. CT
  8. DE
  9. DC
  10. FL
  11. GA
  12. HI
  13. ID
  14. IL
  15. IN
  16. IA
  17. KS
  18. KY
  19. LA
  20. ME
  21. MD
  22. MA
  23. MI
  24. MN
  25. MS
  26. MO
  27. MT
  28. NE
  29. NV
  30. NH
  31. NJ
  32. NM
  33. NY
  34. NC
  35. ND
  36. OH
  37. OK
  38. OR
  39. PA
  40. RI
  41. SC
  42. SD
  43. TN
  44. TX
  45. UT
  46. VT
  47. VA
  48. WA
  49. WV
  50. WI
  51. WY
  • 28Testing program in official text
  • 3State says it requires no emissions test
  • 5Program ended or repealed, says official text
  • 1Repeal not settled
  • 14No official statement found
The same map as a list

Want them side by side? The comparison table has all 51, and states not in the checker has what official text says about the rest.

Why do some places test and others don’t?

The US Environmental Protection Agency puts it this way:

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

US EPA, Overview of Vehicle Inspection and Maintenance (I/M) Programs (EPA-420-F-21-067) · nepis.epa.gov, read November 12, 2026

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

US EPA, Vehicle Emissions Inspection and Maintenance (I/M): General Information and Regulations · epa.gov, read November 12, 2026

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.

US EPA, Overview of Vehicle Inspection and Maintenance (I/M) Programs (EPA-420-F-21-067) · nepis.epa.gov, read November 12, 2026

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

US EPA, Overview of Vehicle Inspection and Maintenance (I/M) Programs (EPA-420-F-21-067) · nepis.epa.gov, read November 12, 2026

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.

US EPA, Overview of Vehicle Inspection and Maintenance (I/M) Programs (EPA-420-F-21-067) · nepis.epa.gov, read November 12, 2026

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

US EPA, Overview of Vehicle Inspection and Maintenance (I/M) Programs (EPA-420-F-21-067) · nepis.epa.gov, read November 12, 2026

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

US EPA, Overview of Vehicle Inspection and Maintenance (I/M) Programs (EPA-420-F-21-067) · nepis.epa.gov, read November 12, 2026

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.

US EPA, Overview of Vehicle Inspection and Maintenance (I/M) Programs (EPA-420-F-21-067) · nepis.epa.gov, read November 12, 2026

Where the answer comes from

For each state we read the official pages and wrote down its rule as a short list of conditions: which places, which model years, which fuels, which weights, and how new a vehicle has to be. Each condition points at the sentence that states it. The checker answers only from those conditions and shows you the sentences. Where the text we could read does not settle a vehicle, the answer is “It depends” and says what is missing. How it works has the method, the official pages that would not open for us, and how to send a correction.

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