Washington Car Seat Law: Rear-Facing to 2, Boosters to 4'9"

Last reviewed: October 18, 2026. This article is general information, not legal advice. Washington's child restraint law was last amended in 2019; check the current text of RCW 46.61.687 before you rely on any detail.

Washington has one of the more detailed car seat laws in the country. Since 2020 it has followed the stages that pediatricians recommend: rear-facing, then a harness, then a booster, then a seat belt, with the booster stage ending at a height, not a birthday. Here's what the statute requires, what changed in 2020, and what happens if you're ticketed. For other states, see our guides to the California booster seat law, Texas car seat laws, Ohio car seat laws and Florida car seat laws.

Short answer: under the Washington car seat law, RCW 46.61.687, a child under 2 must ride rear-facing; a child under 4 who isn't rear-facing must use a forward-facing seat with a harness; and a child who has moved past those seats and is under 4 feet 9 inches must use a booster seat. Children under 13 ride in the back seat where practical. The law covers children under 16, and a violation is a traffic infraction that can be dismissed once if you get the right seat within seven days.

The rules by stage: Washington law vs safety advice

The table compares what Washington law requires with what NHTSA and the American Academy of Pediatrics (AAP) recommend. Washington's statute borrows the AAP's language in places, so the gap is smaller than in most states.

Because the booster rule ends at 4 feet 9 inches rather than an age, a small 10-year-old may still legally need a booster in Washington. Public Health – Seattle & King County notes that children usually reach that height between 8 and 12, and that most children won't fit a seat belt without a booster until about 10 or 11.

What changed in 2020

The current wording comes from Substitute House Bill 1012, which became chapter 59, Laws of 2019 and took effect January 1, 2020. According to the Senate bill report, before the change a child had to be in a child restraint "until the child is eight years old, or taller than 4 feet, 9 inches," with no separate rear-facing-to-2 rule. In summary, the 2019 law:

• required rear-facing until age 2 (or until the seat's rear-facing limits);
• required a forward-facing harnessed seat for children under 4 who aren't rear-facing;
• made the booster stage depend on height (under 4'9"), dropping the age-8 cut-off; and
• told the Washington Traffic Safety Commission to produce educational materials on proper car seat use.

Which vehicles and seats the law covers

The law applies when a child under 16 rides in a motor vehicle that must have seat belts under RCW 46.37.510, or in a neighborhood or medium-speed electric vehicle. The car seat must meet U.S. Department of Transportation standards and be installed following both the vehicle and seat makers' instructions (RCW 46.61.687(1)(d) and (e)).

Two practical carve-outs:

• Lap-belt-only seats: under subsection (7), the booster requirement doesn't apply in a seating position that has only a lap belt.
• Backless boosters count: subsection (6)(a) says a backless booster or belt-positioning system is a child booster seat if it meets the federal standard (49 C.F.R. § 571.213).

Front seat rules

Washington is one of the few states with a back-seat rule in its car seat statute. RCW 46.61.687(1)(f) says the driver of a vehicle carrying a child under 13 "shall transport the child in the back seat positions in the vehicle where it is practical to do so." In a pickup with no back seat, or when every rear seat is taken by younger children in car seats, the front may be the only practical option. Even then, never put a rear-facing seat in front of an active airbag, and push the vehicle seat as far back as it goes.

Exemptions, including taxis and rideshare

Under RCW 46.61.687(5), the law does not apply to:

• for hire vehicles;
• vehicles designed to carry 16 or fewer passengers (including the driver) that are operated by auto transportation companies as defined in RCW 81.68.010;
• shuttles between parking, convention and hotel facilities and airport terminals; and
• school buses.

The statute doesn't mention Uber, Lyft or other rideshare services by name, so don't assume an exemption. The safety risk is the same in any car: bring your child's seat or a travel booster.

Penalties and how to get a ticket dismissed

• Infraction: a violation may be cited as a traffic infraction under chapter 46.63 RCW (RCW 46.61.687(3)).
• Fine: Public Health – Seattle & King County lists the fine for not wearing a seat belt or using an appropriate child restraint as $124. (The 2019 Senate bill report put the fine at $136 at that time, so check the amount on your notice.)
• Dismissal: if, within seven days, you show the jurisdiction that issued the notice proof that you've acquired an approved car seat or booster, and you haven't previously had a violation of this section dismissed, the jurisdiction "shall dismiss" the infraction. This works only once.
• Enforcement: officers check by visual inspection whether the seat suits the child's height, weight and age and is used as the manufacturers instruct (subsection (2)). The 2019 Senate bill report describes failure to use a child restraint as a primary offense in Washington.
• Civil cases: under subsection (4), not complying is not negligence by a parent or guardian, and failing to use a car seat isn't admissible as evidence of negligence in a civil case.

Where to get a free car seat check in Washington

Certified child passenger safety technicians check seats at inspection stations and community events across the state. Use NHTSA's car seat inspection station search, where technicians inspect seats free of charge in most cases. In King County, Public Health – Seattle & King County lists free child car seat check events. Washington law also protects certified technicians who volunteer: under subsection (8), they aren't liable for civil damages for good-faith help, except for gross negligence or willful misconduct.

Practical tips for Washington parents

• Measure your child. The booster stage ends at 4 feet 9 inches and a proper belt fit, not at a birthday.
• Use each seat to its limits. The statute explicitly lets you keep a child rear-facing or harnessed until the seat's maximum.
• Keep kids under 13 in the back seat unless it truly isn't practical.
• If you're ticketed, get the right seat and send proof within seven days. Keep a copy of what you send.

Related reading: children riding in the open bed of a truck.

Sources

• RCW 46.61.687, Child restraint system required: Washington State Legislature
• Senate Bill Report, SHB 1012 (2019), as passed Senate: Washington State Legislature
• Public Health – Seattle & King County, Car seats, booster seats and seatbelts: kingcounty.gov
• NHTSA, Car Seats and Booster Seats (recommendations and inspection station locator): nhtsa.gov
• American Academy of Pediatrics, Car Seats: Information for Families: HealthyChildren.org