Car crashes are one of the leading causes of death for children — and according to the Colorado Department of Transportation, nearly 80% of all car seats and booster seats are used incorrectly . To keep your child safe, make sure you are following  Colorado’s child passenger safety laws, which were updated in 2024 and go into effect Jan. 1, 2025, and the American Academy of Pediatrics' Child Passenger Safety Guidelines. 

Colorado car seat and booster seat laws by age

Choosing the right car seat for your child can be confusing, but by turning to Colorado’s current car seat laws and the American Academy of Pediatrics best practices, you can easily decide which is right for your child based on age, height and weight. Children’s Hospital Colorado recommends that parents always follow the manufacturer's instructions for installation and use, as this varies among different types of car seats.

Infants up to age 2

What Colorado law says: Infants who are under 2 and less than 40 pounds must ride in a rear-facing car seat. Their car seat must be installed in the rear seat of the vehicle if one is available.

Safest practice: The American Academy of Pediatrics advises parents and caregivers to keep their children rear facing as long as possible, up to the weight or height limits of their car seat. Many convertible car seats can be rear facing until your child weighs 40 to 50 pounds. This will include virtually all children under age 2 and most children up to age 4. Never put a rear-facing car seat in the front seat of a vehicle with an active airbag.

Infants are less skeletally mature with heavy heads, fragile necks and stretchy ligaments, making them particularly vulnerable during a car crash. When a baby is riding in a rear-facing car seat, the whole body (head, neck and torso) is cradled by the back of the safety seat — providing much better protection. A rear-facing car seat also protects the baby better in other types of crashes, particularly side impact crashes.

Children between 2 and 4

What Colorado law says: Children who are under 2 but weigh more than 40 pounds or between 2 and 4 who weigh at least 20 pounds may use a forward-facing car seat. They must be positioned in the back seat of the vehicle if available.

Safest practice: Children should ride in a rear-facing convertible car seat as long as possible, up to the seat's limits. This will include virtually all children under 2 years old and most children up to 4 years old. Once they have been turned around, children should remain in a forward-facing car seat up to that seat's weight or height limits. Most seats can accommodate children up to 65 pounds.

Restrain your 2- to 4-year-old child in a car seat with a five-point harness system, which features two shoulder straps, two hip straps and a buckle strap. A five-point harness system has more places to distribute crash forces and offers better protection than a lap and shoulder belt.

Keep your children in the back seat. Always use the top tether strap (the long piece of webbing with a clip on the end located on the top back of a forward-facing car seat) according to the vehicle owner's manual and child restraint manufacturer's instructions.

Children between the ages of 4 and 9

What Colorado law says: Children between the ages of 4 and 9 years old who weigh at least 40 pounds must continue to ride in a child restraint in the back seat of the vehicle. This can be a five-point-harness car seat or a booster seat that uses the vehicle's lap and shoulder seat belt as kids get older and bigger.

Safest practice: Children should be in a booster seat in the back seat until they can use a seat belt that fits correctly. Studies have shown the use of booster seats can reduce the risk of injury by 59% compared to seat belts alone. Keep your child in a booster until:

• The shoulder belt of the car's seat belt crosses their shoulder and chest (not their neck).
• The lap belt crosses their upper thighs (not their abdomen).
• Their knees bend at the edge of the back seat and their feet touch the floor.
• They can stay seated like this for the entire trip.

Children between the ages of 9 and 18

What Colorado law says: Children between the ages of 9 and 18 must use a seat belt or child restraint.

Safest practice: Follow the guidelines above to know when your child can safely stop using a booster. Keep your child in the back seat as long as possible, until at least age 13. Your child is growing up fast, but don't rush them into using the regular seat belt if it doesn't fit properly; it won't protect them in a crash and could actually cause serious injuries.

If your teenager sits in the front seat, put the seat as far back as possible in case the airbag deploys in a crash.

Remember that children learn by watching their parents, and this includes safe driving and always wearing your seatbelt.

Additional car safety tips

In addition to proper car restraint usage, there are a few things you can do to keep your children safe around cars and teach them good car-safety habits.

• Remove your child’s bulky winter coat before they are buckled in, as their harness or seat belt should be snug against their body.
• Don't allow children to play in or around cars.
• Never leave children alone in a car.
• Make sure the area around you is clear before you drive off.
• Seat belts are not toys, so don't allow kids to play with them. Seat belt entanglement is not common, but it can happen.
• Car seats do expire, so keep an eye on the expiration date and be sure to replace them after a crash.
• Avoid distractions while driving, such as cell phones, food and more.

Safe car seat installation

Make sure your car seat or booster is installed correctly to best protect your child. Safe Kids Colorado provides free car seat education and inspection where a certified technician can help with hands-on instruction and installation. Find a car seat inspection station near you. You can find car seats and other important kids safety tools at our Safety Store.

You can also contact a certified child passenger safety technician through the Colorado Department of Transportation's Car Seats Colorado program.