Do you need a motorcycle license to drive a trike in New Jersey?

Yes you do, however there is one exception. Chapter 11 page 166 on the NJ motorcycle Manual states:

According to New Jersey law, a motorcycle can be a motor bike, a bicycle with a motor attached or any motor-operated vehicle of the bicycle or tricycle type, except for a motorized bicycle.

The motor power can be part of the vehicle or attached. The vehicle must have a saddle or seat for the driver to sit astride or upon, or a platform on which to stand. Every New Jersey resident who operates a motorcycle or "trike" must have a New Jersey motorcycle driver license or a motorcycle endorsement on an existing New Jersey basic or commercial license.

One exception exists: The operator of a three-wheeled motor vehicle, equipped with a single cab that has a glazing around the occupant, seats similar to those of a passenger vehicle or truck, seat belts or automotive steering, is not required to have a motorcycle endorsement added to their basic automobile driver license, and is not required to wear a helmet.