From Wikipedia:
Massachusetts General Laws define three classes of motorized two-wheeled vehicles:
Motorcycle,
Motorized bicycle, and
Motorized scooter.
[88] Although the definition of
motorized scooter includes two-wheeled vehicles propelled by electric motors with or without human power, motorized scooter specifically excludes anything which falls under the definitions of motorized bicycle and motorcycle.
Motorized bicycle is a pedal bicycle which has a helper motor, or a non-pedal bicycle which has a motor, with a cylinder capacity not exceeding fifty cubic centimeters, an automatic transmission, and which is capable of a maximum speed of no more than thirty miles per hour.
Motorcycle includes any bicycle with a motor or driving wheel attached, with the exception of vehicles that fall under the specific definition of motorized bicycle. Thus, a pedal bicycle with an electric motor or a non-pedal bicycle with an electric motor, automatic transmission, and maximum speed of 30 miles an hour would fall under the definition of motorized bicycle. An electric bicycle that did not meet those restrictions would be either a motorized scooter or motorcycle, depending on specific characteristics.
A motorized bicycle shall not be operated by any person under sixteen years of age, nor at a speed in excess of twenty-five miles per hour, upon any public highway, private way laid out under authority of statute, way dedicated to public use, or way under the control of park commissioners or body having like powers, within the commonwealth.
[89] A motorized bicycle shall not be operated on any way by any person not possessing a valid driver's license or learner's permit. Every person operating a motorized bicycle upon a way shall have the right to use all public ways in the commonwealth except limited access or express state highways where signs specifically prohibiting bicycles have been posted, and shall be subject to the traffic laws and regulations of the commonwealth and the regulations contained in this section, except that the motorized bicycle operator may keep to the right when passing a motor vehicle which is moving in the travel lane of the way, and the motorized bicycle operator shall signal by either hand his intention to stop or turn. Motorized bicycles may be operated on bicycle lanes adjacent to the various ways, but shall be excluded from off-street recreational bicycle paths. Every person operating a motorized bicycle or riding as a passenger on a motorized bicycle shall wear protective headgear conforming with such minimum standards of construction and performance as the registrar may prescribe, and no person operating a motorized bicycle shall permit any other person to ride a passenger on such motorized bicycle unless such passenger is wearing such protective headgear.
A response to an inquiry made to the Mass DOT/RMV indicates that
Massachusetts does recognize the federal low speed electric bicycle Federal Law (15 U.S.C. § 2085) and interprets that to mean these ebikes do not require license or registration. However, some of the materials available on the RMV website do not distinguish between "Motorized Bicycle" and low power ebikes. One form, Bicycle Conversion to Motorized Bike, does document the exemption of low power ebikes.
