California law requires children under 8 to ride in a car seat or booster seat in the back seat. Children under 2 must ride rear-facing unless they weigh 40 or more pounds or are 40 or more inches tall. Children 8 or older, or at least 4 feet 9 inches tall, may use a standard seat belt if it fits correctly.
Sacramento personal injury lawyers and California personal injury lawyers handle cases involving California booster seat law violations and child passenger injuries. Starting January 1, 2027, AB 435 adds a new 5-step fit test that will change when children ages 8 to 16 can graduate from a booster.
California child passenger restraint law moves through four stages based on age, height, and weight, with each stage governed by a different section of the Vehicle Code.
| Stage | Who It Applies To | Legal Requirement | Best Practice |
| Rear-facing | Under 2, or until 40+ lbs or 40+ inches | Vehicle Code § 27360 | Stay rear-facing until the seat’s manufacturer height/weight limit, not just until age 2 |
| Forward-facing with harness | After outgrowing rear-facing limits | Vehicle Code § 27360 | Keep in harness until the manufacturer’s maximum, CA law sets no weight floor for this transition |
| Booster seat | Under 8 AND under 4’9″ | Vehicle Code § 27360 | Lap belt across upper thighs, shoulder belt across center of chest, never the neck or stomach |
| Seat belt only | 8+ years OR 4’9″+ | Vehicle Code § 27360.5 | Seat belt must fit correctly, starting 2027, children ages 8–16 must pass the 5-step fit test |
For a complete breakdown of requirements by stage, review the California car seat laws page.
AB 435, signed October 7, 2025, takes effect January 1, 2027. Children ages 8 to 15 may only use a seat belt if they pass the 5-step seat belt fit test. If a child fails any one step, they must remain in a booster regardless of age.
| Current law | Starting January 1, 2027 | |
| Who needs a booster | Children under 8 OR under 4’9″ | Children under 8 OR under 4’9″, same base rule |
| Ages 8–15 in a seat belt | Allowed if child is 8+ or 4’9”+ | Must pass the 5-step fit test |
| Booster seat | Under 8 AND under 4’9” | Vehicle Code § 27360 |
The 5-step seat belt fit test, as defined in AB 435:
If the child cannot meet all five steps, they must remain in a booster seat. The test applies to how the seat belt fits the child’s body, not to the child’s age alone.
Drivers who cannot demonstrate that a child aged 8 to 15 passes the test face a fine of up to $490 per violation under the new law.
To see how California’s 2027 change compares to other states, child passenger safety laws by state include a full 50-state breakdown.
Correct installation requires the right method, the right angle, and a final movement check. The seat must not shift more than one inch in any direction when pulled at the belt path.
Use LATCH or the seat belt, not both at the same time, unless the manufacturer’s manual specifically permits it. LATCH lower anchors have a combined child-plus-seat weight limit of 65 pounds. Once the child and seat together exceed that, switch to seat belt installation.
Rear-facing installation:
Forward-facing installation:
Booster seat installation:
Movement check: grab the seat at the belt path and pull firmly. More than one inch of movement in any direction means the seat is not correctly secured.
Free professional installation checks are available from certified Child Passenger Safety technicians at CHP offices, fire stations, and children’s hospitals. Search safekids.org or nhtsa.gov to find a nearby inspection station.
The most common car seat installation mistakes reduce crash protection even when the right seat is used.
Every mistake on this list carries the same consequences as going completely unrestrained. Learn more about why seatbelts save lives and how restraint failures affect crash outcomes.
A first car seat violation in California carries a base fine of $100, which rises to $475 to $500 or more after court fees and penalty assessments are added.
Each child not properly secured counts as one DMV point. Points raise insurance rates and can trigger license suspension under California’s Negligent Operator Treatment System if they accumulate.
Judges may order completion of a child passenger safety course in place of fines for qualifying defendants. DMV points cannot be removed through this option.
If a child was injured in a crash and another driver’s restraint violation contributed, a car accident lawyer can help assess whether a personal injury claim applies.
Thompson Law offers a Free Consultation with No Fee Unless We Win for California families whose children were injured in a car accident. Even when a child is properly restrained, crashes cause serious injuries, and insurance companies frequently dispute or minimize these claims.
If your child was hurt in a crash, contact us today and we can review your case and explain your options.
No. A 4-year-old must ride in a forward-facing seat with a harness, not a booster. California law requires children under 8 to use an appropriate child restraint system, and a 4-year-old has not yet outgrown the forward-facing harness stage under Vehicle Code Section 27360.
Generally no. California law requires children under 8 to use an appropriate restraint, and safety experts recommend keeping children in a high-back booster with a harness until they outgrow it. Backless boosters are appropriate only when the vehicle seat provides adequate head and neck support.
California law does not set specific weight requirements for booster seats. The requirement is age-based: children under 8 AND under 4 feet 9 inches must use a booster. The seat belt must lie across the upper thighs, not the stomach, and the shoulder belt across the center of the chest, not the neck.
Yes. A 7-year-old must still ride in a car seat or booster in the back seat under Vehicle Code Section 27360. The booster requirement applies until the child turns 8 or reaches 4 feet 9 inches tall, whichever comes first.
The base fine for a first car seat violation is $100, but total costs including court fees and penalty assessments rise to $475 to $500 or more. Subsequent violations carry a $250 base fine with totals that can exceed $1,000.
Free car seat installation checks are available from certified Child Passenger Safety technicians at California Highway Patrol offices, fire stations, and children’s hospitals statewide. These checks are free of charge and do not require an appointment at most locations. Search safekids.org or nhtsa.gov to find an inspection station near you.
Sí. Atendemos casos en los que niños resultaron lastimados en accidentes de auto en California, en español, incluidos Sacramento y Los Ángeles. Si tu hijo fue herido, contáctanos para revisar tu caso. La consulta es gratis y no cobramos a menos que ganemos tu caso.
Thompson Law charges NO FEE unless we obtain a settlement for your case. We’ve put over $2.1 billion in cash settlements in our clients’ pockets. Contact us today for a free, no-obligation consultation to discuss your accident, get your questions answered, and understand your legal options.
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