Utah Code § 41-1a-504: Exceptions to title requirements for vehicles.

Each vehicle operated in this state is subject to the titling provisions of this part except:

(1) special mobile equipment;

(2) a vehicle owned or leased by the federal government;

(3) a trailer of 750 pounds or less shipping weight and not designed, used, and maintained for hire for the transportation of property or persons; and

(4) modular and prebuilt homes conforming to the Uniform Building Code and presently regulated by the United States Department of Housing and Urban Development that are not constructed on a permanent chassis.