09/29/2026
4 to 7 years old: Keep your child in a forward-facing car seat with a harness and tether until he or she reaches the top height or weight limit allowed by your car seats manufacturer. Once your child outgrows the forward-facing car seat with a harness, it's time to travel in a booster seat, but still in the back seat.
8 to 12 years old: Keep your child in a booster seat until he or she reaches 4'9". For a seat belt to fit properly the lap belt must lie snugly across the upper thighs, not the stomach. The shoulder belt should lie snugly across the shoulder and chest and not cross the neck or face. Remember: your child must ride in the back seat until age 13.
For more information about Washington State Laws check out: https://wacarseats.com/