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 Arizona, the state's seat belt laws require that all front-seat occupants wear a seat belt, and this is a primary enforcement law. This means that law enforcement officers in Arizona have the authority to stop a vehicle and issue a citation to the driver if the driver or any front-seat passenger is not wearing a seat belt, even if no other traffic violation has occurred. For rear-seat passengers, Arizona's seat belt laws are secondary, which means that officers can only issue citations for not wearing a seat belt if there is another traffic violation. Additionally, Arizona has specific laws for child restraint; children under the age of 8 or shorter than 4 feet 9 inches must be properly secured in a child restraint system, such as a car seat or booster seat, which is a primary enforcement law.