Since it has gears, I would assume you need a motorcycle license (unless you can get it registered as a moped). Technically, the MB5 doesn't meet these requirements according to MA:
Moped Definition According to Massachusetts law, a moped is a "motorized bicycle." In order to be classified as a moped, the vehicle must:
Have a cylinder capacity of no more than 50 cubic centimeters.
Have an automatic transmission.
Be capable of a maximum speed of no more than 30 miles per hour.
Comply with all applicable federal motor vehicle safety standards.
But, i've been riding my Puch Sabre's around and calling them mopeds...no trouble yet in chicago!