Booster seat requirements in Massachusetts
A car seat or booster until age 8.
Unless the child is taller than 57 inches (4 ft 9 in), which ends the requirement whatever their age.
- Seat belt alone from
- age 8
- First offense
- $25
Every figure on this page was read at Mass. Gen. Laws ch. 90, § 7AA on 4 October 2026. Read the statute
What the Massachusetts booster seat law says
The stages below are separate rules in the statute, not one rule in steps.
| Rule | Figure | What Massachusetts requires |
|---|---|---|
| Car seat or booster | under 8 years | Until age 8, unless the child is taller than 57 inches (4 ft 9 in). |
| Adult seat belt alone | from 8 years | Lawful from age 8, or once the child reaches more than 57 inches (4 ft 9 in). |
| Penalty | $25 | $25 for a first offense. Condition The statute sets a ceiling rather than a flat sum: "a fine of not more than twenty-five dollars". It does not apply to the operator of a licensed taxi cab that is not equipped with a child passenger restraint. A violation is not treated as a conviction of a moving violation for insurance surcharge purposes under c. 175, § 113B, and may be contested under c. 90C, § 3. |
Size ends the requirement, whichever comes first. A child who is taller than 57 inches (4 ft 9 in) is out of the booster in Massachusetts 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.
The statute
Massachusetts sets this in Mass. Gen. Laws ch. 90, § 7AA. Read it at the source.
This is information, not legal advice. A city or county in Massachusetts 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
- Mass. Gen. Laws ch. 90, § 7AA
- Source
- malegislature.gov
- Jurisdiction
- Massachusetts (MA), 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