Rule Hub · Car SeatsUS child car seat laws, state by state

Washington car seat laws

RCW 46.61.687 · Last checked September 23, 2026

Car seat stages

The statute text comes first. Numbers are a summary for comparison, not a replacement for the law.

Rear-facing seat

Statute text

A child under the age of two years must be properly secured in a child restraint system that is rear-facing until the child reaches the weight or height limit of the child restraint system as set by the manufacturer.

RCW 46.61.687(1)(a).

What the law sets

Rear-facing seat required by law
Yes
Rear-facing until age
2 years
Rear-facing until weight
Not addressed in statute

No number in RCW 46.61.687(1)(a); the limit is the weight or height limit set by the seat manufacturer.

Rear-facing until height
Not addressed in statute

No number in RCW 46.61.687(1)(a); the limit is the weight or height limit set by the seat manufacturer.

Leaving rear-facing
Meeting any one listed limit is enough

A child leaves rear-facing at age two, or earlier on outgrowing the rear-facing seat's manufacturer weight or height limit.

Recommended (not law)

NHTSA

Children under age 1 should always ride in a rear-facing car seat. Keep your child rear-facing as long as possible — it's the best way to keep them safe — until they reach the top height or weight limit allowed by the car seat's manufacturer.

NHTSA – Car Seats and Booster Seats

AAP

All infants should ride rear-facing, starting with their first ride home from the hospital, and should continue riding rear-facing as long as possible until they reach the highest weight or height allowed by their car safety seat's manufacturer.

HealthyChildren.org (AAP) – Car Safety Seats: Information for Families

Forward-facing harness seat

Statute text

A child who is not properly secured in a rear-facing child restraint system in accordance with (a) of this subsection and who is under the age of four years must be properly secured in a child restraint system that is forward-facing and has a harness until the child reaches the weight or height limit of the child restraint system as set by the manufacturer.

RCW 46.61.687(1)(b).

What the law sets

Forward-facing harness required by law
Yes
Harness until age
4 years
Harness until weight
Not addressed in statute

No number in RCW 46.61.687(1)(b); the limit is the weight or height limit set by the seat manufacturer.

Harness until height
Not addressed in statute

No number in RCW 46.61.687(1)(b); the limit is the weight or height limit set by the seat manufacturer.

Leaving the harness
Meeting any one listed limit is enough

A child leaves the harness at age four, or earlier on outgrowing the harness seat's manufacturer weight or height limit.

Recommended (not law)

NHTSA

Once a child outgrows the rear-facing car seat, they are ready for a forward-facing car seat with a harness and tether. Keep the child in the forward-facing seat until they reach the top height or weight limit allowed by the car seat's manufacturer, then move to a booster seat, still in the back seat.

NHTSA – Car Seats and Booster Seats

AAP

Children should use a forward-facing car seat with a harness after outgrowing the rear-facing weight or height limit. It is best for children to ride in a seat with a harness as long as possible, at least to 4 years of age.

HealthyChildren.org (AAP) – Car Safety Seats: Information for Families

Booster seat

Statute text

A child who is not properly secured in a child restraint system in accordance with (a) or (b) of this subsection and who is under four feet nine inches tall must be properly secured in a child booster seat.

RCW 46.61.687(1)(c). Under subsection (7), the booster rule does not apply in a seating position with only a lap belt.

What the law sets

Booster required by law
Yes
Booster until age
Not addressed in statute

No age limit in RCW 46.61.687(1)(c); the booster stage ends on height alone.

Booster until weight
Not addressed in statute

Not set in RCW 46.61.687(1)(c).

Booster until height
57 in (4 ft 9 in)
Leaving the booster
Meeting any one listed limit is enough

Height is the only limit: a child leaves the booster at 4 feet 9 inches, at any age.

Recommended (not law)

NHTSA

Keep your child in a booster seat until they are big enough to fit in a seat belt properly — the lap belt lying snugly across the upper thighs (not the stomach) and the shoulder belt snug across the shoulder and chest (not the neck or face).

NHTSA – Car Seats and Booster Seats

AAP

All children whose weight or height exceeds the forward-facing limit for their car safety seat should use a belt-positioning booster seat until the vehicle seat belt fits properly, typically when they have reached 4 feet 9 inches in height and are 8 to 12 years of age.

HealthyChildren.org (AAP) – Car Safety Seats: Information for Families

Seat belt

Statute text

A child may continue to be properly secured in a child booster seat until the vehicle lap and shoulder seat belts fit properly, typically when the child is between the ages of eight and twelve years of age, as recommended by the American academy of pediatrics, or must be properly secured with the motor vehicle's safety belt properly adjusted and fastened around the child's body.

RCW 46.61.687(1)(c); the belt applies once a child is at least 4 feet 9 inches tall. The ages eight to twelve are an AAP recommendation quoted in the statute, not a legal limit.

What the law sets

Seat belt alone from age
Not addressed in statute

No age in RCW 46.61.687(1)(c); the belt is allowed by height alone.

Seat belt alone from height
57 in (4 ft 9 in)
Moving to the seat belt
Meeting any one listed limit is enough

Recommended (not law)

NHTSA

Once a child is big enough to fit in a seat belt properly, they can ride with just the lap-and-shoulder belt, but should still ride in the back seat — NHTSA recommends keeping children in the back seat at least through age 12.

NHTSA – Car Seats and Booster Seats

AAP

Children should transition to the vehicle seat belt once it fits properly, typically at about 4 feet 9 inches in height and 8 to 12 years of age; all children younger than 13 years should ride in the back seat.

HealthyChildren.org (AAP) – Car Safety Seats: Information for Families

Front seat

Many states have no front-seat age in statute. Where that is the case, we say so and cite the section we read.

Front seat — statute text
The driver of a vehicle transporting a child who is under thirteen years old shall transport the child in the back seat positions in the vehicle where it is practical to do so.

RCW 46.61.687(1)(f).

Minimum age for the front seat
13 years
Conditions
Children under 13 ride in the back seat where it is practical to do so.

Penalties

What a car seat ticket costs, and whether showing proof of a proper seat can cancel it.

First offense — fine
Up to $250

A violation is a traffic infraction (RCW 46.61.687(3)); RCW 46.63.110(1)(a) caps infraction penalties at $250. The base amount is set by Supreme Court rule, not by statute.

Repeat offense — fine
Up to $250

RCW 46.61.687 sets no separate repeat penalty; the RCW 46.63.110(1)(a) cap of $250 applies.

License points
None

Not set in RCW 46.61.687. Washington assesses no license points: the department suspends for traffic offenses “of such frequency as to indicate a disrespect for traffic laws” (RCW 46.20.291(3)), and its driver improvement rule counts offenses — six in one year or seven in two years (WAC 308-104-025) — instead of assigning points.

Fine waiver
The notice of infraction is dismissed if, within seven days, the driver shows proof of acquiring an approved child restraint system or booster seat and has not had a previous violation of this section dismissed (RCW 46.61.687(3)).

Exemptions

Exempt means the statute excludes it. Silent means the statute does not address it.

Taxis
Exempt

RCW 46.61.687(5)(a) excludes for hire vehicles.

Rideshare (Uber, Lyft)
Not addressed in statute

RCW 46.61.687(5) does not name transportation network companies, and chapter 46.72B RCW does not address child restraints.

Buses
Exempt

RCW 46.61.687(5) excludes school buses and vehicles for 16 or fewer passengers run by auto transportation companies.

Medical exemption
Not addressed in statute

RCW 46.61.687 has no medical exemption.

Out-of-state vehicles
Not addressed in statute

RCW 46.61.687 does not address nonresident drivers or out-of-state vehicles.

How Washington compares

Washington is not ranked on booster age because its law sets a weight or height limit but no age limit.

Compared with Idaho and Oregon, Washington differs on: rear-facing rules (from Idaho), booster rules (from Idaho and Oregon), and front-seat rules (from Idaho and Oregon).

Law compared with the AAP recommendation

  • Washington law: a rear-facing seat is required until the child reaches age 2. AAP recommends: All infants should ride rear-facing, starting with their first ride home from the hospital, and should continue riding rear-facing as long as possible until they reach the highest weight or height allowed by their car safety seat's manufacturer.
  • Washington law: a forward-facing harness seat is required until the child reaches age 4. AAP recommends: Children should use a forward-facing car seat with a harness after outgrowing the rear-facing weight or height limit. It is best for children to ride in a seat with a harness as long as possible, at least to 4 years of age.
  • Washington law: a booster seat is required until the child reaches 57 in. AAP recommends: All children whose weight or height exceeds the forward-facing limit for their car safety seat should use a belt-positioning booster seat until the vehicle seat belt fits properly, typically when they have reached 4 feet 9 inches in height and are 8 to 12 years of age.
  • Washington law: a child may use the seat belt alone once reaching 57 in. AAP recommends: Children should transition to the vehicle seat belt once it fits properly, typically at about 4 feet 9 inches in height and 8 to 12 years of age; all children younger than 13 years should ride in the back seat.

See every state side by side on the comparison pages.

Guides covering Washington

Sources

State law comes from the statute or state agency below. Recommendations come from NHTSA and the American Academy of Pediatrics. The responsible agency is Washington Traffic Safety Commission.

State law

Recommendations

Disclaimer

This page summarizes Washington law for reference. It is not legal or medical advice. The statute text is the law; the numbers are our summary of it. Legal minimums are not safety recommendations: NHTSA and the AAP recommend keeping a child in each stage for as long as the seat allows. Check the statute or Washington Traffic Safety Commission before relying on anything here.