Montana's New Child Car Seat Law: What Parents Need to Know to Keep Kids Safe (Updated with FAQs at the end)

Updated: Aug 4

Keeping our children safe in the car is a top priority for every parent. Now, child car seat laws in Montana have been updated to provide more clarity and enhanced safety standards. This new legislation, House Bill 586, aims to ensure our most fragile passengers are protected on the road.

Why the Change? Strengthening Child Passenger Safety

Montana passed its first seat belt legislation in 1987, but laws regarding child passenger protection had only been updated three times in the past 25 years. Prior to this recent change, the law's guidance was very broad, simply stating that children under age 6 and 60 pounds "must be transported and properly restrained in a child safety restraint". This old law lacked "detail" and didn't always put children in the "safest possible position" for travel.

Rep. Marc Lee, from Butte, is a certified Child Passenger Safety Instructor (CPS-I) sponsored House Bill 586. He stated that instructors used to "half-heartedly joke about how weak Montana’s laws are" regarding child passenger safety, which spurred him to act. The bill received significant bipartisan support in both the House and Senate. This new legislation aligns Montana's child car seat laws with federal standards and adds clear definitions for booster seats, child safety restraint systems, and "properly restrained".

The New Standards: A Breakdown for Parents

The new law replaces the old requirement with specific standards for different ages and stages, ensuring children are in the appropriate restraint system. Here's what you need to know:

Children under 2 years of age: Must be properly restrained in a rear-facing child safety seat that complies with federal safety standards.

Children aged 2 to 4 years old: Must be in a rear-facing seat or a forward-facing seat with an internal harness. The new federal safety standards for car seats indicate that the minimum weight to transition to forward facing is 2 years of age and must be 26.5 pounds or greater.

Children aged 4 to 9 years old: Must be properly restrained in a forward-facing car seat with an internal harness or utilize a booster seat to safely use the car’s shoulder seat belt.

Children at least 9 years of age OR who have outgrown the height or weight limits of a child booster seat as set by the manufacturer (whichever comes first): Must be secured with a motor vehicle adult safety belt.

Recommendation →In the Back Seat until 13: It’s not part of the law, but keeping kids in the back seat until age 13 keeps them away from the front airbags until bone and muscle structure is developed to the point where they can handle the impact forces that can cause more significant injuries to a growing body.

When Does This Law Take Effect?

House Bill 586 goes into effect on October 1, 2025.

Why This Matters: The Impact of Proper Restraint

This law is designed purely for child protection. While the law did not change any penalties, its importance cannot be overstated.

Motor vehicle crashes are the leading cause of death for kids, accounting for around 20 percent of adolescent deaths each year in the United States. Data from the National Highway Traffic Safety Administration shows that proper use of a child car seat can reduce the risk of fatal injuries by 71% for infants and 54% for toddlers. Law enforcement often reports that individuals, including children, have walked away from significant crashes because they were properly restrained in their car seats or wearing seat belts.

Here in Missoula, out of the 162 car seat checks I've personally conducted, 87% have had some form of misuse which is far above the 70% national misusage average.

--- Updated Section ---

Here's some FAQs because I've seen a lot of comments on posts related to the New Montana Car Seat Laws. Sure, I get it...people don't want to be "Told" what to do, but this really about keeping our kids as safe as possible.

The "Why" Behind the New Law

We've seen some great conversations and questions since this new law was announced. It's clear that as parents and caregivers, we all share the same goal: keeping our kids as safe as possible. These new guidelines are based on decades of research into what works best to protect children in a crash. Here are answers to some of the most common questions we've heard.

Q: Where does the "science" for this law actually come from?

This law reflects the unified recommendations of engineers, doctors, and public health experts. Organizations like the National Highway Traffic Safety Administration (NHTSA), the American Academy of Pediatrics (AAP), and the Insurance Institute for Highway Safety (IIHS) have spent decades studying two key things:

Crash Physics: What actually happens to a human body during the violent, split-second forces of a collision.
Child Physiology: How a child's developing body—with its softer bones, larger head, and different proportions—reacts differently to those forces than an adult's.

They analyze data from thousands of real-world crashes and conduct highly sophisticated crash tests. This law simply aligns Montana's rules with the overwhelming scientific consensus on what gives our kids the best chance of survival.

Why do we need a law for this? Shouldn't it be up to parents to decide?

This is a fantastic point. As parents and caregivers, we are constantly making decisions to protect our children, and most Montanans are already doing a great job. We can think of this law not as a mandate, but as a tool that gives all of us a clear, research-backed roadmap for child passenger safety.

Vehicle and crash dynamics are incredibly complex. These updated standards bring the best available science and data to every family in Montana, ensuring we all have access to the same baseline of life-saving information. It helps take the guesswork out of a critical safety decision. The goal is to support parents by making the safest path the clearest path.

Is it really safer to keep my child rear-facing if their legs look cramped?

We hear this concern a lot, and it's completely understandable. It's natural to worry about our child's comfort. However, the safety benefits of keeping them rear-facing are enormous.

What's in it for my child? A young child's head is proportionally much larger and heavier than an adult's, and their spine and neck bones are still developing. In a crash, a rear-facing seat acts like a catcher's mitt, cradling their entire body and distributing the intense forces across the whole shell of the seat. This protects their fragile head, neck, and spine from severe injury. A forward-facing child's head is thrown forward violently, putting immense stress on their neck.
What about their legs? Children are much more flexible than adults! They will often sit comfortably with their legs crossed or bent. More importantly, crash data shows that leg injuries for rear-facing children are extremely rare, while head and spinal cord injuries are the most serious and life-altering threats we are trying to prevent. Keeping them rear-facing as long as possible, until they reach the maximum height or weight limit for their car seat (often 40 or even 50 pounds), gives them the best possible protection
Don't just take my word for it: Check this out: https://thecarseatlady.com/when-should-your-child-turn-forward-facing/

Why does my 8- or 9-year-old still need a booster seat? They seem big enough for a seat belt.

This is one of the most important stages in child passenger safety. The key thing to remember is that seat belts are designed to protect adults, not children. A booster seat's only job is to "boost" a child up so the adult seat belt fits them correctly.

What's in it for my child? Without a booster, the vehicle's seat belt is positioned incorrectly and can cause serious harm in a crash.
- The lap belt rides up over their soft tummy instead of staying low on their strong hip bones. In a crash, this can cause devastating damage to internal organs like the spleen, liver, and intestines.
- The shoulder belt cuts across their neck instead of the center of their chest and shoulder. This is uncomfortable, so kids will often put it behind their back, completely removing all upper-body protection.
  
  A booster seat solves both problems, ensuring the seat belt is positioned on the strongest parts of their body to keep them safe.
- Don't just take my word for it: Check this out: https://thecarseatlady.com/why-boosters-work/

The guidelines mention 4'9". As an adult who isn't that tall, do I need a booster seat?

This question comes up often, and it gets at the heart of why the height guideline exists! The 4'9" rule is specifically for children because their bodies are still developing. An adult's skeletal structure and muscle structure are fully mature and shaped differently. This allows the seat belt to ride safely on the hips, even on a shorter adult.

A child's body isn't developed enough for a safe belt fit until they are taller and can pass the 5-Step Test:

Does their back sit flat against the vehicle seat?
Do their knees bend naturally at the edge of the seat?
Does the lap belt sit low on the hips/tops of the thighs?
Does the shoulder belt cross the center of the shoulder and chest?
Can they remain seated like this for the entire trip?

If the answer to any of these is "no," they still get the safety benefits of a booster seat.

Why is it recommended that my 12-year-old stay in the back seat?

While the law focuses on car seats and boosters and this isn't part of the law it's just an important recommendation. The reason is simple: airbags. Frontal airbags are powerful safety devices designed and tested to protect a full-sized adult. A child's bone structure isn't fully hardened and mature until they are a teenager. The force of a deploying airbag can cause serious, or even fatal, injuries to a child who is not yet developmentally ready for it.

What's in it for my child? The back seat is simply the safest place for them to be, keeping them away from the direct force of a frontal airbag deployment until their body is strong enough (bone and muscle structure) to handle it. For all of us, keeping our kids in the back seat until age 13 is one of the easiest and most effective ways to ensure their safety in the car.
Naturally, there's a chance your child, is 10 years old, 5'10" tall and weighs 220 (I've seen things like this in the comments). Yes, you are the parent and you can let them ride in the front seat, the choice is ultimately yours. This just a recommendation because even full-size adults are typically safer in the rear seats.
Don't take my word for it: Please feel free to research the heck out of all of this and then feel free to make the best choice for you and your family.

Need Help? Resources Are Available!

Reach out to Drive Safe Missoula (sschmidt@missoulacounty.us) and we can help answer questions and help you ensure you know how to install your child's car seat properly.

Outside of Missoula? You might be able to find a Certified Child Passenger Safety Tech in your area here.