Aside from New Hampshire, every State in the union (and Washington D.C.) has a seat belt law for front-seat occupants. But the laws for rear-seat occupants vary wildly between States. In Iowa, for example, there are no laws against riding beltless in the rear seats. But places like Maine, New York, and Oregon require all occupants to be wearing seat belts, no matter where they are in the car.
Things get more complicated once age comes into the equation. In Michigan, for example, you don’t have to wear a seat belt in the rear … so long as you’re 16 years old or older. If you’re under 16, you have to wear a seat belt, no matter where you’re sitting. Many states have similar age-based laws.
Then there are child seat and booster seat laws. Most States have laws that require children under 8 years old or under 4’9″ to use booster seats. California is one such State. But thanks to a new law signed by the Governor back in October, children as old as 16 might soon need to use booster seats if they can’t satisfy the law’s new criteria.
No Set Numbers, Just Smart Parameters
Bill AB 435, which was signed into law by Governor Gavin Newsom and set to take effect on January 1, 2027, was put in place to better ensure that children between eight years old and 16 years old are being afforded the same protections as their younger counterparts. Lawmakers likely discovered that the body types for some children in that age range were still unsuitable for adult passenger restraints.

Instead of increasing the height cutoff requirements, the state has identified five specific parameters that must be met for a child to ride in a vehicle without any additional equipment. And they all seem pretty sensible:
- The child can sit all the way back against the seat
- The child’s knees bend over the edge of the seat
- The shoulder belt sits snugly across the center of the child’s chest and shoulder, not at the child’s neck
- The lap belt is as low as possible and is touching the child’s thighs (not the stomach)
- The child can stay seated in this position for the entirety of the trip
If the child doesn’t meet all five of these criteria, they’ll have to use a booster seat. The driver of a vehicle caught with a child riding in the car and not meeting the criteria could face a fine of up to $490.
Basically, the State just wants to make sure your kid is big enough to sit in a full-size car seat properly. Seat belts, used improperly (like resting on the neck or stomach), can have catastrophic effects in a crash. By putting these common-sense rules in place, both parents and police can quickly and reliably determine whether or not a child actually needs a booster seat, regardless of their age or height.
Won’t You Think Of The Children?

While I’m all for making sure kids are as safe as possible while riding in a vehicle, I feel a little bit bad for kids who might now need to start using booster seats, even as teenagers.
I remember, as a kid, finally being able to ride in a car for the first time without having to get into a booster seat. It might sound like a small thing, but it felt like a rite of passage and part of growing up. Even though I was just nine years old, I felt like an adult. Having to go from recently graduated to normal seating back to a booster seat would be pretty upsetting, to me, at least.
Also, having to ride in a booster seat as a 16-year-old, a.k.a. a sophomore in high school, seems like it’d be the most embarrassing thing on the planet. I wouldn’t put it past any of my high school friends to make fun of me endlessly if they saw me hop up into a booster seat in the back seat of my parents’ car after school. Children are cruel. But at the end of the day, I’d rather my kid be bullied and safely secured in the car.
Top graphic images: Stock.Adobe.com
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