In their newest study, officials said 48 out of 53 models got their seal of approval for the protection they offer children.
RELATED: Should your child ride in a booster seat?
What you need to know about child seat safety
Five models, however, are on the group's list of booster seats they wouldn't recommend this year. These include:
- Cosco Easy Elite
- Cosco Highback 2-in-1 DX
- Diono Olympia
- Diono Pacifica
- Safety 1st Summit 65
If you have one of these seats, do not panic. The IIHS said you can continue to use it, because any booster seat is better than none at all.
But, you need to take a look at the belt fit immediately. If it's not doing a good job, replace it soon with one that works better.
When IIHS first began rating booster seats about eight years ago, only a quarter of seats earned the highest rating.
Booster seats are made for children between 4 and 8 years old who have outgrown their car seats.
SEE ALSO: RELATED: IIHS rates 2015 children's booster seats
The IIHS said kids who sit on the booster seats are 45 percent less likely to be injured in a crash compared to just using seat belts alone, IIHS said.