What Are Child Car Seat Laws in Missouri? A Personal Injury Attorney Breaks Down the Myths and Facts

Car and truck accidents can happen at any time, even to good drivers traveling a short distance. Securing young passengers in an age-appropriate car seat is one of the best things you can do to protect the children in your care.

According to the American Academy of Pediatrics:

  • A child in a car seat is 71% to 82% safer than a child secured by a seat belt and
  • A child in a booster seat is 45% safer than a child secured by a seat belt.

You might be a good driver making a short trip down the block, but you can’t predict when another driver might swerve across the center line or blow through a stop sign, putting everyone in your car in danger.

Missouri Car Seat Laws

In Missouri, drivers are responsible for making sure every passenger younger than 16 is buckled up – whether it’s your child or not. The kind of restraint the law requires depends on the age and size of the child.

Read More: Should I choose a forward-facing or rear-facing car seat?

Missouri car seat law by age

  • Children younger than 4, regardless of weight, must be in a car seat
  • Children between 4 and 8 must be in a car seat or booster seat unless they meet the size requirement to rely on a seat belt
  • Children between 8 and 16 must be in a booster seat or restrained by a seat belt

Missouri car seat law by size

In a car accident, physics doesn’t care how old a child is. A child who is small and light needs to be restrained differently than a child who is tall and heavy. It’s important to choose a restraint system that fits the child.

  • Children weighing less than 40 pounds, regardless of age, must be in a car seat
  • Children between 40 and 80 pounds AND less than 4 feet 9 inches tall must be in a car seat or booster seat
  • Once a child is more than 80 pounds or more than 4 feet 9 inches tall, they are big enough to rely on the vehicle’s seat belt

When to Move from a Car Seat to a Booster Seat to a Seat Belt

Under Missouri state law, children must be at least 4 years old AND 40 pounds before moving from a car seat with a five-point harness to a booster seat.

Children should ride in a booster seat until they are at least 80 pounds or 4 feet 9 inches tall. Seat belts are not designed to fit smaller riders.

Car seats and booster seats are labeled with minimum and maximum height and weight limits. A good rule of thumb is to wait until a child hits the maximum limit before moving them up to the next level of restraint.

Before moving your child out of a booster seat, make sure the seat belt fits them properly. A properly-fitting lap belt should lie across the hips and upper thighs, not the stomach. The shoulder harness should lie snug across the shoulder and chest, not the neck or face. If the seat belt does not hit the child’s body at the right points, keep them in their booster.

Do I Need a Car Seat for a Taxi or Uber?

Missouri does not require car seats or booster seats in a public carrier for hire, such as a taxi or an Uber.

That said, public carriers are not immune from auto accidents. To keep kids safe, car seats or booster seats should still be used if possible.

When you book your ride, you can ask if the driver has a seat available, but be prepared to provide your own.

When Can Kids Ride in the Front Seat in Missouri?

Buckle up, because the answer to this question tends to shock people

Missouri has no state law preventing children from riding in the front seat of a vehicle, as long as they are properly restrained Now, just because something is legal doesn’t mean it’s a good idea. The National Highway Traffic Safety Administration, the American Academy of Pediatrics and pure common sense all tell us vehicle restraint systems are designed for adults, not kids. The safest place for kids younger than 13 is in the back seat, for two important reasons.

  1. Even if a pre-teen is the size of an adult on the outside, they still have an immature skeleton. This puts them at a greater risk of internal injuries in a vehicle collision.
  2. The back seat is farther from the windshield, dashboard and airbags – three things responsible for most auto accident injuries.

Missouri Seat Belt Laws

In Missouri, drivers and front seat passengers must always wear a seat belt – no exceptions.

Back seat passengers 17 and older are not required to wear a seat belt – though it’s safer for everyone in the car if they do.

Children 16 and younger who have outgrown a booster seat must always wear a seat belt, no matter where in the car they are seated.

The Difference Between Rear-Facing, Forward-Facing, and Booster Seats

There are 3 types of child safety restraint systems: rear-facing car seats, forward-facing car seats and booster seats. While state law does specify children must be 4 years old and 40 pounds before moving from a car seat to a booster, it does not specify whether children must ride facing the front or rear.

Rear-facing car seats

Though it’s not required by law, it’s recommended children younger than 2 ride rear facing for as long as possible. This is because rear-facing seats provide extra support to the neck and spine. Babies and toddlers have relatively large heads and weak necks, putting them at a high risk of injuries in a crash.

If you bought a rear-facing or infant-only car seat, there’s a good chance your baby will outgrow it before their first birthday, even though they should keep riding backward for another year. A convertible car seat changes from rear-facing to forward-facing, allowing children to ride rear-facing for longer.

Forward-facing car seats

When your child outgrows their rear-facing car seat, it’s time to switch them to a front-facing model (or, if you have a convertible car seat, to turn it around).

Both rear-facing and forward-facing car seats have a five-point harness to keep the child safely buckled into the seat. The harness should fit the child snugly. In a collision, a few inches of slack in the harness could result in a child being tossed around in their seat, causing injuries.

Booster seats

Keep your child in a forward-facing car seat until they reach the seat’s maximum height or weight limit. At that time, you can move the child into a booster seat.

Unlike a car seat, a booster does not have its own harness. It’s designed to boost the child up so the vehicle’s seat belt fits properly.

High-back boosters provide neck and head support and are recommended for vehicles with low seat backs or no headrests. If your vehicle has back seat headrests, you can opt for a backless booster.

To determine if your child is ready to move out of the booster seat, answer these 3 questions:

  1. Can the child comfortably sit with their back against the back of the seat and knees bent over the front?
  2. Does the shoulder harness come across the shoulder and chest, NOT against the neck or face?
  3. Does the lap belt lie across the hips and upper thighs, NOT across the abdomen or stomach?

If the answer to any of these questions is “no,” play it safe and keep your child in a booster a little longer.

Install Car Seats Correctly

The NHTSA says almost half of all car seats are installed incorrectly.

To make sure your child’s seat is installed safely, you can have it checked at your local car seat inspection station. If there is not a station near you, you may be able to find a certified safety technician using this directory or through your local police or fire department.


Failure to abide by Missouri’s child safety seat laws is punishable by a $50 fine.

Gonzalo Fernandez is a personal injury attorney based in St. Louis. He regularly uses his legal expertise to offer insight on events impacting Missourians, including car seat and driver’s license laws. Recent media appearances include the St. Louis Post-Dispatch, CBS St. Louis, Fox 2, and KPLR 11. To speak to Gonzalo, call (314) 433-9131 or email gonz@stltriallawyers.com.

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