States typically handle enforcement of seat belt laws in one of two ways - primary enforcement or secondary enforcement.
Primary enforcement allows law enforcement officers to pull over drivers and give them tickets for not wearing their seat belts even if there are no other traffic violations.
Secondary enforcement means that law enforcement officers can only write seat belt violations if they have stopped a driver for another violation and then see the seat belt violation.
Montana is a secondary enforcement state, meaning that law enforcement officials can only write seat belt tickets if the driver has been stopped for another traffic violation.