Traffic Safety · Car Seat & Booster
Car Seat & Booster Laws in California
When your child can move from a booster to a seat belt in California — plus rear-facing, front-seat, and the fine, with the law kept separate from best practice.
Check your child's stage in California
Enter age, height, and weight. We show the California law separately from best practice.
4′9″ = 57 in. Enter only the boxes you have — this state uses exit at age 8 or 4′9″, whichever comes first.
Educational guide to the minimum legal requirement, not legal or safety advice. Best practice is often stricter than the law. Always follow your car seat’s manufacturer instructions, and confirm the current rule with the official source below — last reviewed 2026-07-09.
The four stages in California
Each rung is tagged Law or best practice.
California requires a child to ride rear-facing until age 2, unless the child weighs 40 lb or more or is 40 in or taller.
California does not split forward-facing out by age — a child under 8 must ride in an appropriate restraint (car seat, then booster) in the back seat.
A child under 8 must be secured in a booster or child restraint unless they are at least 4′9″ tall.
Exit rule: exit at age 8 or 4′9″, whichever comes first. The adult belt must fit — lap low across the hips, shoulder belt across the chest.
Front seat, the fine & the source
Seating rule, the exact booster logic, and any recent change.
A child under 8 must ride in the back seat, with narrow exceptions (no rear seat, all rear seats already used by children under 8, the restraint cannot be installed in back, or a medical reason). This is law.
| Booster exit logic | Age 8 or 4′9″ — whichever first |
| Seat belt OK | Age 8, or under 8 once 4′9″ or taller |
| First-offense fine | $100 $100 for a first offense and $250 for each later offense, plus court costs and penalty assessments (§27360.6). |
| Statute | Cal. Veh. Code §§27360, 27363, 27360.6 |
AB 435 (signed October 2025) adds a 5-step fit test for ages 8–15 and a ban on rear-facing seats in front of an active airbag — but it is not operative until January 1, 2027. The rules on this page are the ones in effect now.
What California parents get wrong
California is one of the eight states that actually legislate the rear-facing stage by age: Vehicle Code §27360 requires rear-facing until age 2 unless the child is 40 lb or 40 in. The most-searched question — when a child can stop using a booster — has a clean answer here: age 8 or 4′9″, whichever comes first. California also has a real front-seat law (children under 8 must ride in back, with limited exceptions), which many states only recommend. One thing to get right on timing: AB 435 was signed in October 2025 and adds a 5-step fit test plus a rear-facing-airbag ban, but it does not take effect until January 1, 2027 — so the numbers that govern today are the ones above, not the 2027 version some blogs already describe. The first-offense fine is $100 (rising to $250 for later offenses), before court costs.
Common questions
When can a child stop using a booster seat in California?
At age 8, or once the child reaches 4′9″ — whichever comes first. Below both thresholds a booster or child restraint is required, and the seat belt must fit correctly.
Does California require rear-facing car seats by age?
Yes. California is one of the states that legislate it: rear-facing until age 2, unless the child weighs 40 lb or more or is 40 in or taller.
Do children have to sit in the back seat in California?
Yes — for children under 8, it is the law, with narrow exceptions (no rear seat, all rear seats used by younger children, the restraint cannot be installed in back, or a medical reason).
What is California AB 435 and is it in effect?
AB 435 (signed October 2025) adds a 5-step fit test for ages 8–15 and a rear-facing-airbag ban. It is not operative until January 1, 2027, so it does not govern yet — the current rules still apply.
Not legal advicePlainStatute provides plain-language summaries of public law for general information only. This is not legal advice. Statutes change; always confirm current requirements with the official source linked above before acting.