Code of Massachusetts Regulations
540 CMR - REGISTRY OF MOTOR VEHICLES
Title 540 CMR 22.00 - Miscellaneous Motor Vehicle and Trailer Equipment and Operations
Section 22.08 - Protective Headgear for Motorcycle Operators and Passengers

Every operator of or passenger on a motorcycle or motorized bicycle, including a passenger in a sidecar, shall wear a helmet, with a suitable retaining device in position, designed and manufactured to protect at least the area of the wearer's head above a reference plane 2.36 inches (60 mm.) above and parallel to a plane defined by the level of the external ear openings and the lower rim of the eye openings.

Each such helmet shall meet or exceed the standards established in the United States Department of Transportation's Federal Motor Vehicle Safety Standard No. 218, at 49 CFR 571.218 for motorcycle helmets as enacted and from time to time amended.