Tools · Car Seat
Montana Car Seat & Booster Checker (2026)
Enter your child's age, height, and weight to see the minimum seat stage Montana law requires and the first-offense fine (Up to $100). This is the legal minimum — not best safety practice.
Montana car seat checker
4′9″ = 57 in. Enter only the boxes you have. Montana uses the belt is legally OK at age 9 (or earlier if the child passes the booster’s manufacturer height/weight limit); the statute sets no 4′9″ or pound figure of its own.
Heads up: Montana replaced its old law (child under 6 AND under 60 lb) with HB 586, effective October 1, 2025. The new age ladder codifies rear-facing under 2, a harness or booster through age 8, and the adult belt at 9. Summaries still quoting "under 6 and 60 lb" describe the repealed rule.
- Child
- Not entered
- Minimum legal stage
- Enter age / height / weight
- Booster-exit rule
- the belt is legally OK at age 9 (or earlier if the child passes the booster’s manufacturer height/weight limit); the statute sets no 4′9″ or pound figure of its own
- First-offense fine
- Up to $100
Plain-language summary, not legal advice.
This shows the minimum legal requirement in Montana, not best safety practice, which is usually stricter, and not legal or safety advice. Always follow your car seat's manufacturer instructions. For the full four-stage rules, front-seat rule, and citation, see the Montana car seat law reference, cited to Mont. Code Ann. §61-9-420 (+ §61-9-423) (last reviewed 2026-07-11).
How Montana car seat law works
Montana rewrote its child-passenger law with HB 586, effective October 1, 2025, so any summary quoting "under 6 and under 60 pounds" is describing the repealed version. The current statute sets a clean age ladder: rear-facing under 2, a rear- or forward-facing harness from 2 up to 4, and a forward-facing harness or booster from 4 up to 8. A child can move to the adult belt at 9, or sooner if they outgrow the booster’s manufacturer limit. Unlike states that legislate rear-seat placement, Montana does not put children in the back by law; the NHTSA "back seat through 12" line is guidance here. The first-offense fine is capped at $100 and is waived if you show proof of buying a proper restraint within 7 days.
This checker shows the Montana minimum legal requirement — not best safety practice, which is usually stricter — and is not legal or safety advice. For the full four-stage rules, front-seat rule, and citation, see the Montana car seat law reference.
Car seat checkers for other states
Same tool, each with its own booster-exit rule.