I/M programs were developed during the 1970s in the United States, where government regulations imposing I/M programs spawned a billion-dollar vehicle-testing and consulting industry. In spite of the fact that in the United States, I/M programs have never been shown to provide anywhere near the benefits its supporters promised, the programs continue to be very popular with industry, government bureaucrats, and non-profit organizations.

Inspection and maintenance (I/M) programs place a legal requirement upon the owners of private cars and light trucks to submit their vehicles to a scheduled test for excessive emissions every year or every two years. Vehicles that fail the test must either be repaired and pass a re-test or receive a waiver to remain on the road. The owners of the vehicles must pay for both the test and the repairs.

I/M programs were developed during the 1970s in the United States, where government regulations imposing I/M programs spawned a billion-dollar vehicle-testing and consulting industry. In spite of the fact that in the United States, I/M programs have never been shown to provide anywhere near the benefits its supporters promised, the programs continue to be very popular with industry, government bureaucrats, and non-profit organizations.