Inspection & Maintenance (I/M)

I/M Legislation

An Act to Provide Further Regulatory Relief to the Citizens of North Carolina
(Session Law 2017-10, Senate Bill 131)


The North Carolina vehicle Inspection & maintenance (I&M) program started in 1982 with Mecklenburg County being required to have an I&M program to address violations of the CO NAAQS. In 1984, Wake County was added to the program for CO NAAQS violations. With the passage of the CAA Amendments of 1990, Cabarrus, Davidson, Durham, Forsyth, Gaston, Granville, Guilford, and Union Counties were added to the I&M program to address violations of the ozone and/or CO standards. The I&M program was also implemented in Orange County although it was not designated as nonattainment for the ozone or CO NAAQS. Under the 1997 8-hour ozone standard, the Charlotte/Gastonia/Rock Hill area was designated as a moderate nonattainment area, which required Iredell, Lincoln, and Rowan Counties to be included in the I&M program.

In 1999, Senate Bill 953 (Session Law 1999-328) required an additional 36 counties to have the vehicle emissions program to improve air quality in North Carolina. Counties were added to the program based on population, vehicle miles traveled, and the likely contribution by motor vehicles to high ozone levels in these counties and nearby counties. This expanded the program to a total of 48 counties.

The I&M program for the original nine counties subject to the program was based on a “tail-pipe” test. Starting in October 2002, the original nine counties converted from tail-pipe testing to the new On-board Diagnostic (OBD) emissions testing for all model year 1996 and newer light-duty gasoline vehicles and continued tailpipe testing of model year 1995 and older vehicles.

Session Law 2011-95 enacted by the North Carolina General Assembly exempted plug-in electric vehicles from the I&M requirement. In 2012, the North Carolina General Assembly enacted Session Law 2012-199 which required DEQ and DMV to change the I&M program to exempt the three newest model year vehicles with less than 70,000 miles, and secure EPA approval.

In 2013, Session Law 2013-413, section 26, indicated that “The Department of Environment Quality shall conduct a study to examine whether all of the counties covered under the emissions testing and maintenance program are needed to meet and maintain the current and proposed federal ozone standards in North Carolina.

The 2017 session of the North Carolina General Assembly enacted Session Law 2017-10, Senate Bill 131 (An Act to Provide Further Regulatory Relief to the Citizens of North  Carolina). Section 3.5.(a) of the Act amended North Carolina General Statute (NCGS) §143-215.107A(c) to remove 26 of 48 counties from North Carolina’s emissions I&M program. For the 22 counties remaining in the I&M program, the Act also amended NCGS §20-183.2(b) by changing the vehicle model year coverage.


Legislative Study Reports