Apr 30th, 2026

California Car Seat Laws in 2026 & 2027: What Every Parent Needs to Know

A caring adult secures a smiling child in a car seat, reflecting safety and nurturing support.

Keeping your child safe in the car isn’t just common sense — it’s the law. And in California, that law is detailed, specific, and changing. Whether you’re a new parent choosing your first infant seat or wondering whether your 10-year-old still needs a booster, this guide has you covered.

We’ll walk you through California’s current car seat requirements, the important new law taking effect January 1, 2027, how to make sure your seat is installed correctly, and what happens if the rules aren’t followed. We’ll also tell you what to do if your child is injured in a car accident — because even the best precautions can’t stop another driver from making a dangerous mistake.

Why Car Seat Safety Matters: The Numbers

Car crashes remain one of the leading causes of death for children in the United States. In 2023 alone, 555 child occupants under age 13 died in traffic crashes, and over 125,000 were injured, according to NHTSA.

The good news: properly used car seats make an enormous difference. According to NHTSA, correctly installed car seats reduce the risk of fatal injury by 71% for infants (under 1 year old) and 54% for toddlers (ages 1–4) in passenger car crashes. Booster seats reduce the risk of injury for children ages 4–8 by an additional 45% compared to seat belts alone.

The bad news: nearly half of all car seats are installed incorrectly. That means well-meaning parents are unknowingly reducing their child’s protection every day.

Current California Car Seat Law (2026): Age, Size & Stage Requirements

California’s car seat requirements are set out in Vehicle Code § 27360 and related sections. Here’s what the law currently requires, broken down by stage:

Stage 1: Rear-Facing Car Seats

Who: Children under 2 years old must ride rear-facing — unless they weigh 40 or more pounds OR are 40 or more inches tall.

The law: California Vehicle Code § 27360 requires rear-facing placement for children under 2 who haven’t reached those weight/height thresholds. The seat must comply with the manufacturer’s height and weight limits.

Best practice: The American Academy of Pediatrics (AAP) recommends keeping children rear-facing until they reach the maximum height or weight limit allowed by their specific car seat — not just the legal minimum. Many modern convertible seats allow rear-facing well beyond age 2, often up to 40–50 lbs. Rear-facing distributes crash forces across the head, neck, and spine, providing the best protection for young children.

Stage 2: Forward-Facing Car Seat with Harness

Who: Children who have outgrown their rear-facing seat’s limits.

The law: California doesn’t specify a mandatory weight threshold for the forward-facing stage — the requirement is that children under 8 must use an appropriate child restraint system. The transition from rear- to forward-facing should happen when the child reaches the manufacturer’s rear-facing weight or height limit.

Best practice: Keep children in a forward-facing seat with a 5-point harness for as long as the seat allows. Most forward-facing harness seats accommodate children from about 22–65 lbs, though many premium seats go up to 80–90 lbs. Longer in a harness = more protection.

Stage 3: Booster Seat

Who: Children under 8 years old AND under 4 feet 9 inches (57 inches) tall must use a car seat or booster in the back seat.

The law: Under Vehicle Code § 27360, children under 8 must be secured in a rear seat in an appropriate child restraint system. A child under 8 who is at least 4’9″ may use a seat belt instead — but a booster is still recommended if the belt doesn’t fit properly.

Best practice: A booster repositions the adult seat belt so the lap belt lies across the upper thighs (not the stomach) and the shoulder belt crosses the center of the chest (not the neck). This dramatically reduces injury risk. Don’t rush this transition.

Stage 4: Seat Belt

Who: Children 8 years old or older — OR any child who has reached 4’9″ — may use a standard adult seat belt.

The law: All children under 16 must be restrained by either a child restraint system or a properly fitting seat belt (Vehicle Code § 27360.5). Children under 13 should always ride in the back seat, away from front-seat airbags.Important: “Using a seat belt” doesn’t just mean clicking the buckle. Starting January 1, 2027, California law will require the belt to actually fit correctly — see the next section.

Quick Comparison: California Car Seat Stages 2026

Age/Stage	Who It Applies To	Key Requirement	Best Practice
Rear-Facing	Under 2 yrs (unless 40+ lbs or 40+ in)	Must face rear; follow manufacturer limits	Keep rear-facing as long as seat allows
Forward-Facing	After outgrowing rear-facing	Appropriate harness seat; in back seat	Stay harnessed until outgrowing the seat
Booster	Under 8 years AND under 4’9″	Child restraint or booster in back seat	Don’t transition until belt fits properly
Seat Belt	8+ years OR 4’9″+	Properly restrained by belt; under 16 must be secured	After passing 5-step test (2027+)

New for 2027: California’s 5-Step Seat Belt Fit Test (AB 435)

On January 1, 2027, California’s Assembly Bill 435 (signed by Governor Newsom on October 7, 2025) takes effect. This is the most significant update to California child passenger safety law in years — and it affects children ages 8 through 15.

What Changes?

Under current law, a child who turns 8 (or reaches 4’9″) can use a standard seat belt. The law simply requires that a seat belt be used — not that it actually fits.

Starting in 2027, the law changes the definition of “properly restrained by a safety belt.” A child ages 8–15 will only be considered properly restrained if they pass all five steps of the 5-Step Seat Belt Fit Test:

The child sits all the way back against the auto seat — not perched on the edge or slouching.
The child’s knees bend comfortably over the edge of the seat — their legs aren’t dangling or sticking straight out.
The shoulder belt crosses the center of the child’s chest and shoulder — not riding up on the neck or tucked behind the back.
The lap belt lies as low as possible across the thighs — not cutting across the stomach.
The child can stay seated this way for the entire trip — not sliding down or repositioning mid-ride.

If a child cannot meet all five criteria with a seat belt alone, they need to remain in a booster seat — regardless of age.

What About Front Seats?

The final version of AB 435 retained existing rules. Children under 13 should remain in the back seat. The law does not create a new blanket ban on teens in the front seat, but back-seat placement remains strongly recommended for safety.

What Are the Fines?

Drivers who cannot demonstrate that a child aged 8–15 meets the 5-Step Test face a fine of up to $490 per violation.

What Should You Do Right Now?

You have until January 1, 2027, to prepare. Here’s what we recommend:

Don’t put your booster seat away just because your child turned 8. Test the belt fit first.
Practice the 5-step test with your child so they understand why it matters.
If your child fails the test, consider a high-back booster for additional support.
Check your child’s fit regularly — bodies change, especially during growth spurts.

How to Install a Car Seat Correctly

Getting the right seat is only half the battle. Here’s how to make sure it’s actually protecting your child:

Follow the manual — both of them. Your car seat has an installation manual. Your vehicle has one too. Both matter. Check the car seat manual for height and weight limits, harness adjustment instructions, and expiration dates. Yes — car seats expire (usually 6–10 years from manufacture).

Use the two-finger test. After fastening the harness, try to pinch the webbing at your child’s collarbone. If you can grab a fold of strap, it’s too loose. The chest clip should sit at armpit level.

LATCH or seat belt — not both. Use either the LATCH system or the vehicle seat belt to secure the base — not both together (unless your manual specifically allows it). The seat should not move more than one inch side to side or front to back at the belt path.

Center rear seat is safest. The back center seat is statistically the safest position in most vehicles, as it’s farthest from side-impact zones.

Get a free professional inspection. Even parents who’ve read every manual can miss something. Certified Child Passenger Safety Technicians offer free inspections at many fire stations, CHP offices, and children’s hospitals. You can find an inspection station near you at nhtsa.gov or safekids.org.

Penalties for Violating California Car Seat Laws

California takes child passenger safety seriously. Here’s what’s at stake if the law isn’t followed:

Fines: The base fine for a first violation is $100 per child who isn’t properly secured. After fees and penalty assessments, the actual total can exceed $500. A second or subsequent offense carries a base fine of $250, which with assessments can top $1,000. Under the 2027 5-Step Test law, failing that test carries a fine of up to $490.

DMV Points: Each violation adds one point to the driver’s record per child not properly secured. Points raise insurance rates and can lead to a suspended or revoked license if they accumulate.

Court-Ordered Education: Courts may require the driver to attend a certified child passenger safety class.

In a Crash: Improper restraint doesn’t just risk a ticket — it can worsen injuries, complicate insurance claims, and in serious cases, expose a driver to child endangerment charges.

What If Your Child Is Injured in a Car Accident in California?

Even parents who do everything right — the correct seat, installed correctly, every single time — can’t control other drivers. If your child or family is injured in a car crash because of someone else’s negligence, you deserve real answers and real help.

Sam & Ash Injury Law represents families throughout California (and Nevada) who’ve been hurt in car accidents. We know how overwhelming it can feel to navigate medical bills, insurance adjusters, and legal deadlines while also caring for an injured child. That’s why we fight hard, communicate clearly, and never charge a fee unless we win your case.

California: 949-304-2000 Nevada: 702-820-1234 samandashlaw.com Available 24/7 — free consultation, no fees unless we win.

Additional Resources

Find a car seat inspection station: nhtsa.gov/car-seats-and-booster-seats
Safe Kids Worldwide inspection events: safekids.org
California Vehicle Code § 27360: leginfo.legislature.ca.gov
CHP Child Safety Seat Program: chp.ca.gov/programs-services/programs/child-safety-seats
AB 435 full text: legiscan.com/CA/bill/AB435/2025

This article is for informational purposes only and is not legal advice. Laws change; always verify current requirements with the California Highway Patrol or a licensed attorney. If your family has been injured in a car accident, contact Sam & Ash Injury Law for a free consultation.