Maryland Truck Emissions & Clean-Truck Rules
Maryland adopted Advanced Clean Trucks (COMAR 26.11.43), but that is a zero-emission sales quota on manufacturers and dealers, not a rule you face at the roadside. It never fines an out-of-state truck driving through. Governor Moore's April 2025 executive order handed MDE enforcement discretion and waived penalties for model year 2027 shortfalls, roughly a two-year delay. Maryland runs no heavy-truck emissions inspection. Your real obligation is federal: keep the DPF/DEF working. Deleting it risks about $45,000 per engine.
How Maryland handles truck emissions
Maryland adopted Advanced Clean Trucks (COMAR 26.11.43), but that is a zero-emission sales quota on manufacturers and dealers, not a rule you face at the roadside. It never fines an out-of-state truck driving through. Governor Moore's April 2025 executive order handed MDE enforcement discretion and waived penalties for model year 2027 shortfalls, roughly a two-year delay. Maryland runs no heavy-truck emissions inspection. Your real obligation is federal: keep the DPF/DEF working. Deleting it risks about $45,000 per engine.
What applies to you
- Program: ACT adopter
- State rule: Maryland adopted the Advanced Clean Trucks rule (COMAR 26.11.43, Clean Trucks Act of 2023), a zero-emission SALES mandate on truck manufacturers and dealers beginning model year 2027. It binds who sells or delivers new trucks in Maryland, not an out-of-state driver passing through. Governor Moore's April 2025 executive order gave MDE enforcement discretion and waived penalties for model year 2027 shortfalls (and 2028 conditionally), roughly a two-year delay. Maryland runs no heavy-truck emissions inspection.
- Penalty: ACT penalties fall on manufacturers, not drivers, and none applies to a truck driving through. Federal Clean Air Act tampering penalties still apply: about $45,000 per tampered engine and about $4,500 per defeat device.
- DPF / DEF: Federal EPA equipment nationwide, never delete or tamper with it
Maryland Emissions FAQ
Does Maryland have a truck emissions program?
What is the emissions rule for trucks in Maryland?
What is the penalty for an emissions violation in Maryland?
Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://mde.maryland.gov/programs/air/MobileSources/Pages/Clean-Energy-and-Cars.aspx. See our Terms & Disclaimer.
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