Do you need a license for a 150cc moped?

Answer 1

Yes, and in fact in almost all states you will need a motorcycle license and not just a moped license, as a Moped is generally considered to be a cycle with a 50cc engine or smaller.

It also needs to be registered with the DMV and pass an inspection (some states do not require inspections, however - you'll need to check for yourself) AND you need to carry liability insurance to be able to LEGALLY ride it on the roads.

If you go to http://www.moped2.org/mstates.htm all the state moped drivers license requirements are listed.