Except for New Hampshire, all states and the District of Columbia require adult front-seat occupants of motor vehicles to use seat belts. Adult rear-seat passengers are also covered by the laws in 31 states and the District of Columbia. Children are covered by separate laws.

State seat belt laws are divided into two categories: primary and secondary. Primary seat belt laws allow law enforcement officers to stop a motor vehicle and to issue a ticket or citation to a driver or passenger for not wearing a seat belt without any other traffic offense having occurred. Secondary seat belt laws only allow law enforcement officers to issue a ticket or citation for not wearing a seat belt when there has been another traffic offense by an occupant of the vehicle for which the occupant may be issued a ticket or citation.

In Idaho, the state's seat belt law is a primary enforcement law for all front-seat occupants, meaning that law enforcement officers can stop a vehicle and issue a citation to the driver if the driver or any front-seat passenger is not wearing a seat belt, without needing any other reason for the traffic stop. For rear-seat passengers, the law is secondary, which means that officers can only issue a citation for not wearing a seat belt if there is another traffic violation. Additionally, Idaho has specific child restraint laws that require appropriate car seats and booster seats for children under a certain age and size. These laws are designed to ensure the safety of all vehicle occupants and to reduce the risk of injury or death in the event of a traffic accident.