As a Child Passenger Safety Specialist, I often get questions from parents and caregivers about the stages of car seat use. Most parents understand the importance of using car seats, but sometimes are anxious to move their child from one stage to another. In particular, I notice this with school-aged children, who are more conscious about what their peers are doing and want to be seen as “grown up.”

Here is some information about child passenger safety for older children.

What is the difference between a “car seat” and a “booster seat?”

A car seat has a harness to keep your child restrained during a crash. A booster seat, formally called a belt-positioning booster seat, positions your child so the lap and shoulder belt (adult seat belt) fits over the stronger bony parts of his/her body – the shoulders, chest, and hips – instead of on soft body parts like the neck or stomach. The seat belt restrains the child, just as it does for you and me.

When is my child ready for a booster seat?

A child should be in a car seat with a harness until they are at least four years and at least 40 pounds AND they can sit with the lap and shoulder belt properly positioned at all times (Never use a booster seat with just a lap belt).

“Properly positioned” means the shoulder harness is across the shoulder and chest with minimal, if any, slack and the lap belt is snug and and low across the hips after fastening. If a child slouches, leans over, falls asleep, or moves the shoulder belt under their arm or behind their back, the seat belt will not be in the right position to do its job and may cause injury.

With these factors in mind, it is best to wait until age five or six to change to a booster seat. Read your car seat’s labels and instruction manual to determine height and weight limits, and keep your child in the harnessed seat for as long as possible. Remember, whether your child is in a harnessed car seat, a booster seat, or is old enough and big enough for just the vehicle seat belt, they should ride in the back seat until they are 13.

What are the types of booster seats?

The National Highway Traffic Safety Administration lists these types of seats that are, or can become, a booster seat:

  • Booster Seat with High Back: This type of booster seat is designed to boost the child’s height so the seat belt fits properly. It also provides neck and head support and is ideal for vehicles that don’t have headrests or high seat backs.
  • Backless Booster Seat: A backless booster seat is designed to boost the child’s height so the seat belt fits properly. It does not provide head and neck support. It is ideal for vehicles that have headrests.
  • Combination Seat: As a child grows, this seat transitions from a forward-facing seat with a harness into a booster.
  • All-in-One Seat: This seat can change from a rear-facing seat to a forward-facing seat (with a harness and tether) and to a booster seat as a child grows.

When can my child use just the vehicle seat belt?

The American Academy of Pediatrics recommends that children use a belt-positioning booster seat until the vehicle lap and shoulder belt (adult seat belt) fits properly. This is typically when the child is between 8 and 12 years of age. Studies show that booster seat use can reduce risk of injury in a crash by 45 percent over a seat belt alone. Many states (including Vermont) require by law that children travel in a child seat or booster seat until at least age 8.

Take this five-step test to determine if your child is ready for a seat belt:

  1. Does the child sit all the way back against the vehicle seat?
  2. Do the child’s knees bend comfortably at the edge of the vehicle seat with the feet touching the floor?
  3. Does the belt cross the shoulder between the neck and arm?
  4. Is the lap belt as low as possible, touching the thighs?
  5. Can the child stay seated like this for the whole trip?

If you answered “no” to any of these questions, your child should remain in the booster seat, regardless of his/her age. It also may be that your child can ride safely without a booster seat in one car but not in another car or even in another seating position in the same vehicle (e.g., a 3-row SUV), so try this test in all vehicles and vehicle seats in which your child rides.

How can I learn more about booster seat safety?

Here are some resources:

Maureen Johnson is the Child Passenger Safety Specialist at The University of Vermont Medical Center.

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