<P> The California Smog Check Program requires vehicles that were manufactured in 1976 or later to participate in the biennial (every two years) smog check program in participating counties . The program's stated aim is to reduce air pollution from vehicles by ensuring that cars with excessive emissions are repaired in accordance with federal and state guidelines . With some exceptions, gasoline - powered vehicles that are six years old or newer are not required to participate; instead, these vehicles pay a smog abatement fee for the first 6 years in place of being required to pass a smog check . The six - year exception does not apply to nonresident (previously registered out - of - state) vehicles being registered in California for the first time, diesel vehicles 1998 model or newer and weighing 14,000 lbs or less, or specially constructed vehicles 1976 and newer . The program is a joint effort between the California Air Resources Board, the California Bureau of Automotive Repair, and the California Department of Motor Vehicles . </P> <P> A Smog Check is not required for electric, diesel powered manufactured before 1998 or weighing over 14,000 lbs, trailers, motorcycles, or gasoline powered vehicles 1975 or older . In April 2015, hybrid vehicles became subject to smog check requirements . </P>

When is the first smog check required in california