Miss. Code Ann. § 63-2-1

(1) When a passenger motor vehicle is operated in forward motion on a public road, street or highway within this state, every operator and every passenger shall wear a properly fastened safety seat belt system, required to be installed in the vehicle when manufactured pursuant to Federal Motor Vehicle Safety Standard 208. (2) “ Passenger motor vehicle ” for purposes of this chapter means a motor vehicle designed to carry fifteen (15) or fewer passengers, including the driver, but does not include motorcycles that are not autocycles as defined in Section 63-3-103 , mopeds, all-terrain vehicles or trailers. (3) This section shall not apply to: (a) Vehicles which may be registered for “farm” use, including “implements of husbandry” as defined in Section 63-21-5(d) , and “farm tractors” as defined in Section 63-3-105(a) ; (b) An operator or passenger possessing a written verification from a licensed physician that he is unable to wear a safety belt system for medical reasons; (c) A passenger car operated by a rural letter carrier of the United States Postal Service or by a utility meter reader while on duty; (d) Buses; or (e) A child who is required to be protected by the use of a child passenger restraint device or system or a belt-positioning booster seat system under the provisions of Sections 63-7-301 through 63-7-311 .