Understanding testing deadlines is important for staying compliant, especially if you manage exempt, out-of-state, or standard California-registered vehicles. Exempt and non-California vehicles do not receive a Clean Truck Check exemption—their testing timelines are based on the last digit of the VIN. Regular plated vehicles, however, can test up to 90 days before their DMV renewal and follow deadlines tied to their registration month.

Below, you’ll find detailed tables outlining the exact compliance periods for exempt, out-of-state, and registered plate vehicles, including annual and semi-annual testing schedules.