Booster seat requirements in California
A car seat or booster until age 8.
Unless the child is at least 57 inches (4 ft 9 in) tall, which ends the requirement whatever their age.
- Rear facing until
- 24 months
- Back seat until
- age 8
- Seat belt alone from
- age 8
- First offense
- $100
That is the law today. A change takes effect on 1 January 2027 and does not apply yet. What it changes.
Every figure on this page was read at Cal. Veh. Code §§ 27360, 27363 on 4 October 2026. Read the statute
What the California booster seat law says
The stages below are separate rules in the statute, not one rule in steps. The back seat requirement and the restraint requirement are different obligations, and a child can be caught by both at once.
| Rule | Figure | What California requires |
|---|---|---|
| Rear facing | under 24 months | Until 24 months (2 years), unless the child is at least 40 inches (3 ft 4 in) tall or weighs at least 40 lb. |
| Car seat or booster | under 8 years | Until age 8, unless the child is at least 57 inches (4 ft 9 in) tall. |
| Back seat | under 8 years | Required for a child under age 8. |
| Adult seat belt alone | from 8 years | Lawful from age 8, or once the child reaches 57 inches (4 ft 9 in). |
| Penalty | $100 | $100 for a first offense. Condition Plus court costs, which California notes take the real figure well above the fine. A point is added to the driving record. |
Size ends the requirement, whichever comes first. A child who is at least 57 inches (4 ft 9 in) tall is out of the booster in California whatever their age. A child who has not reached that stays in one until age 8. The size is an escape from the age rule rather than a second thing that also has to be true.
Where this and size guidance disagree, follow the stricter one. A belt that crosses the neck rather than the middle of the chest is worse protection than a booster even where the statute allows it.
Not in force yet: California booster seat law change in 2027
This is law that has been passed and is not in effect. It does not apply today and is kept separate from the rule above for that reason. Nothing here changes the answer at the top of this page until the date given.
-
Takes effect
A five step fit test replaces the height rule for ages 8 to 15
AB 435 redefines what counts as properly restrained by a safety belt for passengers aged 8 to 15. From 1 January 2027 the belt has to fit: back fully against the seat, knees bending at the seat edge, shoulder belt across the middle of the chest and not the neck, lap belt low across the thighs, and the child able to hold that position for the whole journey.
AB 435 (2025-2026), approved by the Governor 7 October 2025. Read the bill.
The statute
California sets this in Cal. Veh. Code §§ 27360, 27363. Read it at the source.
This is information, not legal advice. A city or county in California can set a stricter rule than the state one, and an officer enforces the text of the statute rather than a summary of it. Where this page and the statute differ, the statute is right and this page is a bug.
Where this comes from
- Statute
- Cal. Veh. Code §§ 27360, 27363
- Source
- leginfo.legislature.ca.gov
- Jurisdiction
- California (CA), state law only
- Last reviewed
- 4 October 2026 0 days ago
- Read at the statute
- 4 October 2026
- Signed off by a person
- Not yet
- Not in force yet
- 1 change, from 1 January 2027
- Amendment history
- Stats. 2015, Ch. 292 (AB 53), operative 1 January 2017