Moving across state lines resets a family’s car seat questions the same way it resets vehicle registration and driver’s license deadlines — except nobody sends a reminder for this one. There’s no paperwork that flags it, no office visit that requires it, and the rules genuinely differ enough that a seat a child is done with in one state can still be required for years in another.
Here’s what actually changes state to state, and is worth rechecking specifically after a move.
The booster age can shift by years, not months
Booster requirements end at a specific age in 49 of the 51 states and DC, and that age ranges from 5 to 10 — the two states without a numeric age, Delaware and Washington, use a height or manufacturer limit instead. A child who just aged out of the booster requirement in South Dakota, which sets the age at 5, would still need one for three more years after a move to a state using the most common age, 8 — and for five more years after a move to Hawaii, which sets it at 10. This is the single biggest gap in the data, and the one most likely to catch a family off guard, because “old enough for no booster” doesn’t travel with the child the way a birthday does.
The rear-facing rule might not exist at all — or might work differently
Thirty-two states set a rear-facing requirement with a numeric age (one or two years, depending on the state); the other 19 have no rear-facing rule in their child restraint statute. Moving between those two groups doesn’t change what’s actually safe for an infant, but it does change what the law requires — and it’s worth knowing which group the new state falls into before assuming the old state’s rule still applies.
It’s also worth checking how the rule is written, not just what age it names. Some states end the rear-facing requirement the moment a child hits any one of a listed age or weight — Alabama’s statute, for instance, requires rear-facing “until at least one year of age or 20 pounds,” whichever comes first. Others keep the requirement in place until every listed condition is met — Louisiana, for example, requires both the age and an outgrown manufacturer weight or height limit before a child can move to forward-facing, joined with “and” rather than “or.” Two states can list what looks like the same age and mean different things by it.
The front-seat age is the most likely to be missing entirely
Only 19 states set a minimum age for the front seat, ranging from 1 to 13; the other 32 have no front-seat statute at all. A family moving from a state with a front-seat age to one without won’t find a replacement rule waiting — there simply isn’t one on the books, even though the AAP’s back-seat-until-13 recommendation doesn’t change with the move.
Exemptions for taxis and rideshare are not the same state to state
Thirty-one states exempt taxis from the car seat requirement by name; three require a seat in a cab regardless. Rideshare vehicles are addressed even less often — only three states mention Uber, Lyft or TNC vehicles specifically, and one of the three (Indiana) exempts them while the other two (Iowa, Utah) require a seat and put the duty on the riding adult. A family that got used to one state’s answer on either question shouldn’t assume the new state answers it the same way, since most states never wrote a rule on rideshare at all.
Where to check the new state’s actual numbers
None of this is a reason to guess. Each state’s own page here lists its rear-facing, forward-facing, booster and front-seat rules together with the exact statute text, the exemptions for taxis and rideshare, and the date the data was last verified — that’s the source to check after a move, rather than carrying over what applied in the old state. The comparison pages are the fastest way to see how the old and new state differ side by side, stage by stage, before the family’s next trip in the car.