MD HB1556

Prohibits the Department of the Environment from implementing Advanced Clean Trucks regulations until the required needs assessment and deployment plan is published, with implementation starting model year 2028 if published by December 1, 2025, or model year 2029 if published later

Limits enforcement of penalties against motor vehicle manufacturers for failing to meet Advanced Clean Cars II requirements for model years 2027 and 2028 to cases where manufacturers representing at least 40% of Maryland's passenger car and light truck market share have agreed to the enforcement terms

Requires manufacturers to have entered enforcement agreements between January 1, 2025 and January 1, 2026 for model year 2027 enforcement, or between January 1, 2025 and January 1, 2027 for model year 2028 enforcement

Preserves the annual percentage sales targets established under both the Advanced Clean Cars II and Advanced Clean Trucks programs, clarifying this act does not affect those targets

Takes effect October 1, 2025