Booster Seat Law (Children) by State

Every US state requires children to use a booster seat or appropriate child restraint past the toddler years, but the specific age, height, and weight thresholds at which booster requirements end vary widely by state. Boosters lift the child up so the vehicle's lap belt sits across the upper thighs (not the soft belly) and the shoulder belt crosses the collarbone (not the neck). Without a booster, a regular adult seatbelt sits in the wrong place on a small body and dramatically raises the risk of internal injury in a crash.

The American Academy of Pediatrics recommends children stay in a booster until they reach 4 feet 9 inches tall (around 57 inches) AND they pass the "5-step test" — knees bend at the seat edge, back is flat against the seatback, lap belt low across hips, shoulder belt mid-chest, child can sit still the whole ride. Most children don't pass that test until they're 10 to 12 years old, which is much older than most state laws require. State laws are the legal minimum; the AAP guideline is the safety standard. There's a real gap between the two.

Booster laws differ in three ways: the age threshold (varies from 5 to 9 across states), the height threshold (often 4 ft 9 in / 57 inches), and the weight threshold (usually 60 to 80 lbs). Some states use AND (must meet all three to graduate); some use OR (any one triggers graduation); the strictest states combine them. Enforcement varies — most states make it a primary offense (officer can pull you over just for this), some make it secondary (only if pulled over for something else). Fines run from $25 to $500. Many states offer free or discounted car seat fittings through fire departments or hospitals.