Every parent driving through Los Angeles, San Diego, or the Central Valley eventually asks the same question: when can my child leave the booster seat behind? The California law for booster seats lays out clear age and height rules, and 2026 is a transition year before a bigger update takes effect in 2027.
Current California Booster Seat Requirements
Who Needs a Booster Seat
Under California Vehicle Code Section 27360, children under 8 years old must ride in an appropriate child restraint system, which includes a booster seat once a child has outgrown a forward facing harness. A child may move out of a booster only after turning 8 or reaching 4 feet 9 inches in height, whichever comes first, under Vehicle Code Section 27363.
Where the Booster Seat Must Be Placed
California law requires children under 8 to sit in the back seat. Children under 13 should stay in the back seat even after they graduate to a regular seat belt, since front airbags pose a risk to smaller bodies.
The 2027 Update Parents Should Know About Now
Governor Newsom signed Assembly Bill 435 in October 2025, and its provisions begin rolling out on January 1, 2027. This law does not change the current booster seat age, but it adds a new safety standard for older kids before they can ride with a seat belt alone.
The Five Step Seat Belt Fit Test
Starting in 2027, children between 8 and 15 who no longer use a booster must pass a five step fit test. The child needs to sit fully back against the seat, bend their knees naturally at the edge, keep the shoulder belt across the chest instead of the neck, keep the lap belt low across the thighs, and hold that position for the entire ride. If a child fails even one step, they must continue using a booster.
New Fines for Non-Compliance
Once the 2027 rules are active, families who do not comply can face fines up to 490 dollars per violation. Current penalties for booster seat violations remain lower, so parents should treat this as a warning to prepare early rather than wait for enforcement to begin.
Booster Seat Types Allowed in California
California law does not require a specific booster style, but two options meet the standard. A high back booster gives head and neck support and works well in vehicles without built in headrests. A backless booster is lighter and suited for older children riding in seats that already have proper headrests.
Tips to Stay Compliant on California Roads
Measure your child’s height every few months rather than relying on age alone. Keep your child in a five point harness as long as the seat allows before moving to a booster. Run the five step fit test even before 2027 to see how your child’s seat belt actually fits. Keep the booster in the back seat at all times.
Frequently Asked Questions
Can my 8 year old stop using a booster seat in California?
Only if they are also at least 4 feet 9 inches tall, or once the belt passes the fit test after the 2027 rule takes effect.
Does California law require a specific booster brand or type?
No. Any booster that meets federal safety standards and fits the child properly satisfies the California law for booster seats.