The electric motor on E-bikes counts as an engine, so E-bikes are regulated as motor vehicles in all states that recognize their existence. Motor size and power will usually determine whether or not you have to have a driver's license to operate one, to register it and get a license plate, or whether you need to carry liability insurance for it. In many cases E-bike riders are required to wear helmets, even though pedal cyclists may be exempted from the helmet law.