EPA Stops Another California Scheme to Impose its Costly Vehicle Policies on Entire Country

EPA Stops Another California Scheme to Impose its Costly Vehicle Policies on Entire Country

Agency Announces Final Disapproval of CA Heavy-Duty Vehicle Rule Pertaining to Out-of-State, Out-of-Country Vehicles

January 27, 2026

WASHINGTON - Today, U.S. Environmental Protection Agency (EPA) announced the agency's final disapproval of California's Heavy-Duty (HD) Inspection and Maintenance (I/M) Regulation under the Clean Air Act (CAA) to the extent the regulation applies to out-of-state and out-of-country registered vehicles. EPA determined that California's unprecedented attempt to establish an I/M program in its State Implementation Plan (SIP) for heavy-duty vehicles that pass-through California, regardless of where the vehicle was registered, may violate Federal law. Specifically, EPA determined that California failed to provide necessary assurances as required by Section 110 of the CAA, that implementing the Regulation would be consistent with the U.S. Constitution's Commerce Clause, which prevents states from interfering with interstate and international trade. EPA approval was limited to the aspect of the Regulation in California's SIP only as it applies to in-state registered vehicles.

"The Trump EPA will never back down from holding California accountable and stopping them from imposing unnecessary regulations on the entire nation. If California had its way, prices would skyrocket for truckers and businesses across America. Affordable trucks are vital for keeping food and goods moving and prices low for families," said EPA Administrator Lee Zeldin. "Americans didn't vote for California's policies to be imposed nationwide. They voted for President Trump's policies that put working families first."

The agency also said that California's attempt to apply these truck inspection rules to vehicles from other countries violates federal authority over foreign policy matters, and that applying the regulation to out-of-state registered vehicles is not a proper use of the CAA's planning provisions, which empower each state to promote air quality.

EPA is committed to following the law and its statutory obligations as written. While California may force costly regulations on vehicles registered in its own state, EPA will not allow California to impose those costly regulations on American truck drivers and engine manufacturers in other states or countries for its own purposes by misusing the CAA.

Prior to its finalization, EPA held a 30-day public comment period. The final action can be viewed here.

Background

EPA's partial approval will allow the regulation to become federally enforceable for non-gasoline combustion vehicles over 14,000 pounds registered in California.