Car seat laws in Washington

A child under 2 must be in a rear-facing child restraint until reaching the seat's weight or height limit. NHTSA and the AAP recommend going further: keeping your child rear-facing as long as possible, until they reach the top height or weight limit allowed by the car seat's manufacturer. A child under age 1 should always ride rear-facing, and most convertible seats allow rear-facing for 2 years or more.

A child who is not in a rear-facing or harnessed seat and is under 4'9" must be in a booster seat (there is no age cutoff). The booster rule does not apply where only a lap belt is available. NHTSA and the AAP recommend going further: using a belt-positioning booster seat after your child outgrows the harnessed seat, until the vehicle seat belt fits properly, typically when they reach about 4 feet 9 inches tall and are 8 to 12 years old. The AAP says an adult seat belt fits when: the shoulder belt lies across the middle of the chest and shoulder, not the neck or throat; the lap belt is low and snug across the upper thighs, not the belly; and the child is tall enough to sit against the vehicle seat back with knees bent over the edge of the seat without slouching, and can stay that way for the whole trip. NHTSA uses the same lap-belt and shoulder-belt checks. The 5-step test, which California writes into law from January 1, 2027, asks: 1) Does the child sit all the way back against the seat? 2) Do the knees bend over the edge of the seat? 3) Does the shoulder belt snugly cross the center of the chest and shoulder, not the neck? 4) Is the lap belt as low as possible, touching the thighs? 5) Can the child stay seated like this for the whole trip?

A driver transporting a child under 13 must use the back seat where it is practical to do so. That matches NHTSA and AAP guidance: keeping all children younger than 13 in the back seat.

Traffic infraction. Child restraint violations are not listed in the court penalty schedule, so the default base penalty of $48 plus statutory assessments applies (local court rules may differ). The ticket is dismissed if the driver shows proof of getting an approved child seat or booster within 7 days and has never had one dismissed before.

NHTSA's locator lists 112 car seat inspection stations in Washington, in 77 cities and towns. Moses Lake and Seattle have the most (5 each). NHTSA flags 4 of them as Spanish-speaking. Certified technicians check seats for free in most cases. Search NHTSA's locator by ZIP code and call the station before you go.