A bus will require a special endorsement on your license if your seating is 15 or more people, regardless of age of the bus. Most insurers will NOT insure a bus!!! If your state will let you title it as a MOTOR HOME, you'll be in much better shape and can get insurance through groups such as Good Sam Club or several other RV clubs that have special discounts provided to them by various underwriters.
Motor homes do NOT require special endorsements or licenses. A BUS registration or title will result in higher fees and possibly per-mile taxes having to be paid, depending on the state of registration. Do NOT call your bus a "conversion" at the DMV, either. "Conversions", in the eyes of a lot of insurance companies, implies cheapness and shoddy construction. Painting your bus any color other than yellow helps your cause, too, believe it or not!!! Get rid of all of the school bus lettering, seats, outside warning lights, the stop sign, and any other school identifiers.
