Buckling up a child correctly is one of the simplest ways parents across Montana can protect their kids on the road.
Whether you are driving through Missoula, Billings, Bozeman, or the backroads near Kalispell, understanding the Montana law for booster seats helps you avoid fines and, more importantly, keeps your child safer in a crash.
Montana updated its child passenger safety rules in 2025 under House Bill 586, and those requirements remain in effect through 2026.
What Montana’s Child Passenger Safety Law Requires
Montana Code Annotated 61-9-420 breaks restraint requirements down by age instead of relying on one broad rule for every child.
Children Under Age 2
Kids younger than 2 must ride in a rear-facing child safety seat that meets federal motor vehicle safety standards.
Children Ages 2 to 4
Once a child turns 2, Montana law allows either a rear-facing or forward-facing seat with an internal harness, depending on the height and weight limits set by the seat manufacturer.
Children Ages 4 to 8
This is where the booster seat law applies most directly. Children between 4 and 8 years old must be properly restrained in a forward-facing seat with an internal harness or a booster seat secured with a lap-shoulder seat belt.
Age 9 and Older
Once a child turns 9, or outgrows the manufacturer’s height and weight limits for a booster seat, whichever comes first, they may move to a standard adult seat belt.
Fines and Penalties for Non-Compliance
Violating the child restraint requirement carries a fine of 100 dollars. Parents who receive a citation get a seven day waiver if they acquire the correct seat or have it installed properly and show proof to the court.
Exemptions Under Montana Law
Certain vehicles and situations fall outside these requirements, including motor homes, buses, taxis, ambulances, and other emergency vehicles. A child with a physical or medical condition, or a body size that prevents safe use of a restraint system, may also qualify for an exemption.
Best Practices Montana Families Should Follow
The statute sets a minimum standard, but safety experts recommend going further. Many child passenger safety technicians across the state suggest keeping kids in a booster seat until they reach about 4 feet 9 inches tall, often between ages 8 and 12, since seat belts are built for adult bodies. Children are generally safer riding in the back seat until at least age 13 as well.
Where Montana Parents Can Get Help
A large share of car seats statewide are still installed incorrectly. The Montana Department of Transportation and local fire departments in cities such as Missoula, Bozeman, and Kalispell offer free car seat checkup events where certified technicians inspect installations and answer questions.
Final Thoughts
Montana’s 2026 booster seat rules are built around age, height, and weight rather than one single cutoff. Learning the Montana law for booster seats and pairing it with expert safety recommendations gives your child the best possible protection every time you get in the car.