Posted March 10, 2026: Clean Truck Check program requirements are in effect for subject vehicles, including vehicles registered outside of California when operating in the state, to report, pay an annual compliance fee, and submit required passing emissions tests.
On January 27, 2026 U.S. EPA announced its partial disapproval of the State Implementation Plan (SIP) relating to Clean Truck Check.This only means that the state cannot credit the portion of emissions reductions from out-of-state vehicles as part of meeting federal air quality standards. This decision does not extend to determining, or enforcing, any part of Clean Truck Check to ensure all vehicles operating in California abide by the same rules, including vehicles registered outside of California.
This is affirmed in footnote 49 of U.S. EPA's final rule on Clean Truck Check (Heavy-Duty Inspection and Maintenance Program).
