Health Encyclopedia

Installing and Using Child Safety Seats and Booster Seats

Correct restraints for children riding in motor vehicles depend on the child's age and size. Restraints to keep a child safe in the car include:

  • Infant safety seats

  • Child safety seats

  • Child booster seats

  • Correctly used safety belts

The key to keeping your child safe is to use an age-appropriate child restraint that is correctly installed and used.

Infant and child safety seats come in many shapes and sizes. The best child safety seat for a family is the one that is correct for the child's age, weight, and size. It's also one that's easy for the parents or caregivers to use, fits in the family vehicles' seats, and works the vehicles' seat belts or lower anchor and tether system.

Woman securing baby in carrier.

The American Academy of Pediatrics (AAP) has advice for using child safety seats:

  • Babies and toddlers should ride in a rear-facing car safety seat in the back seat, for as long as possible. That means until they reach the top weight or height allowed by their seat. Check your car safety seat directions.

  • Don't put a rear-facing car safety seat in the front passenger seat of any vehicle that has a passenger-side front air bag. This practice prevents the risk for death or serious injury from impact of the air bag against the safety seat. All children younger than 13 years should ride in the back seat.

  • Premature and small babies should not be placed in car safety seats that have shields, abdominal pads, or arm rests. These could hit a baby's face and neck during an impact. Ask your child's healthcare provider if you have questions about the correct seat for your baby.

  • In rear-facing car safety seats for babies, set shoulder straps in the lowest slots until the baby's shoulders are above the slots. The harness must be snug. Put the car safety seat's retainer clip (chest clip) at the midpoint of the baby's chest. Don't put it on the abdomen (belly) or in the neck area. Check your safety seat directions.

  • Make sure the car safety seat is at the correct angle so that the baby's head does not fall forward. Check the directions from the maker of your child safety seat.

  • Convertible car seats can be used rear-facing. They can be converted to forward-facing for older children when they outgrow either the weight or height limit for rear-facing. Most convertible seats have height and weight limits that will allow children to ride rear-facing for 2 years or more. Check your car safety seat directions.

  • Use a booster seat when the child has outgrown a convertible safety seat or forward-facing seat but is too small to fit correctly in a vehicle safety belt.

  • Use a belt-positioning booster seat that has a combination lap and shoulder belt. The National Highway Traffic Safety Administration advises against a booster seat that has a small shield instead of a shoulder belt.

The infant safety seat

Infant safety seats are often small and portable. They are for babies up to age 1 and weight 35 pounds. Infant seats are rear-facing. They may come with a 3-point or a 5-point harness. Some infant seats come with detachable bases that can be left belted into the vehicle. This means you don't need to install the seat each time. Some bases also are adjustable to correctly recline the baby. Some infant seats are rear-facing only. Others convert to a forward-facing position when your child reaches a certain height or weight. Always check the car seat direction manual for how to correctly use the seat.

The child safety seat

Babies and toddlers should ride in a rear-facing car safety seat for as long as possible. That means until they reach the top weight or height allowed by their seat. Child safety seats can be convertible or forward-facing.

  • Convertible seats. Most convertible seats have height and weight limits that will allow young children to ride rear-facing for 2 years or more. Check your car seat manual to know when you can switch the seat from rear-facing to forward-facing. Check the car safety seat maker's directions for how to adjust the shoulder straps and use seat belt correctly.

  • Forward-facing seats. These are for children who have outgrown the weight or height limit for their rear-facing or convertible seat. These children should use a forward-facing seat with a harness for as long as possible. This means up to the weight or height limit set by the car seat maker.

The booster seat

When your child is taller or weighs more than the limit for their forward-facing car seat, switch to a belt-positioning booster seat. Booster seats help raise up your child so that the vehicle's seat belts fit correctly.

Always put booster seats in the back seat of the vehicle. There are 2 types of booster seats:

  • High-back booster. This is a booster seat that helps protect the head and neck in back seats that don't have head restraints. The vehicle's lap and shoulder belts are used to secure the child. 

  • Backless booster. This is a booster seat that raises the child up so that the vehicle's lap and shoulder belts correctly restrain the child.

Checking your car seat

Some of the most common mistakes in installing or using child safety seats include:

  • Safety belt doesn't hold the seat in tightly or is not in locked mode

  • Harness straps are not snug or positioned correctly

  • Harness retainer clip (chest clip) is not at armpit level

  • Locking clip is not used correctly

  • Car seat was recalled and not repaired. This includes booster seats.

  • Babies are placed rear-facing in front of an active air bag

  • Children are turned forward-facing before the height or weight limit listed by their car seat

Carefully read your vehicle owner's manual and the directions that come with the child safety seat. Check that the seat is correctly installed. Use the seat correctly. Always keep the child's safety seat direction manual in the car for easy reference.

Here are some questions to ask yourself:

  • Is your child riding in the back seat? The back seat is the safest place in a crash.

  • Is your child facing the correct way? Babies and toddlers should ride in a rear-facing car safety seat for as long as possible. That means until they reach the highest weight or height allowed by their seat.

  • Is the child safety seat held tightly in place by the seat belt or lower anchor and tether system?

  • Does the harness buckle snugly around your child?

  • Does your older child fit correctly in the vehicle's seat belts? The shoulder belt should rest over the shoulder and across the chest, not the neck. The lap belt should fit low and snug over the upper thighs, not the belly. The child should be tall enough to sit with knees bent at the edge of the seat without slouching.

Replacing child safety seats and seat belts after a crash

Once a vehicle has been in a severe crash, replace child safety seats and seat belts. They may have become stretched or damaged. All child safety seats are replaced by insurance companies. Always check with your child safety seat maker for any questions about the safety of your child's seat.

When car seats are recalled

Sometimes child safety seats are recalled for safety reasons. It's important to register your car seat so you can be told if the seat is recalled. To check if your child safety seat has been recalled, call the seat's maker or the National Highway Traffic Safety Administration Vehicle Safety Hotline at 888-327-4236 or visit nhtsa.gov. If the seat has been recalled, you will be told how to fix it, or how to get parts to fix it.

Online Medical Reviewer: Dan Brennan MD
Online Medical Reviewer: Liora C Adler MD
Online Medical Reviewer: Tara Novick BSN MSN
Date Last Reviewed: 3/1/2023
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