2017 IIHS Booster Seat Ratings

(Last Updated On: November 23, 2017)

Each year since 2009, the Insurance Institute for Highway Safety has released their IIHS booster ratings. In the past, these ratings were based primarily on the fit of the 6 year old crash test dummy. This year’s results were based on a new dummy!

IIHS describes the JASPER dummy as:

“IIHS assesses boosters using a special dummy representing an average-size 6 year-old. Engineers measure how three-point lap and shoulder belts fit the dummy in each of the tested boosters under four conditions that span the range of safety belt configurations in vehicle models. An overall rating for each booster is then assigned based on the range of scores for the lap and shoulder belt measurements.”

We’re excited to see this change in testing protocol.

Fit is the best indication of performance: regardless of how many optional features a booster seat has, if it doesn’t place the vehicle seat belt properly on the child, it can’t do its job.

Proper Booster Seat Belt Fit

Proper booster seat fit

Proper booster seat fit in a Graco Affix

Before getting too concerned about these ratings, learn about proper booster and vehicle seat belt fit.

Poor Booster Seat Belt Fit

Booster seats seem simple enough but there are a few moving parts when it comes to seat belt fit.

Here are a few things to watch out for:

  • A vehicle lap belt that is either too high on the child’s stomach or too low on the child’s thighs
  • A vehicle shoulder belt that slides off the edge of the child’s shoulder
  • A vehicle shoulder belt touching the child’s neck
  • A vehicle shoulder belt that hovers in front of the child’s chest instead of crossing the torso firmly and evenly

Why Booster Seats are Important

High back and backless booster seats

High back and backless booster seats

It’s crucial that children who are at least 5 years old, have outgrown their harnessed seats, and do not yet pass the Five Step Test to sit in only a vehicle seat belt continue to ride in a belt positioning booster until they are 10-12 years old.

Types of Booster Seats

Belt positioning booster seats are available in a few flavors.

  • Standalone high back booster seats
  • Backless booster seats
  • As one mode of a multimode car seat
  1. Backless Boosters: Backless boosters are placed under the child and have no back.  We recommend this type of booster seat for children who are at least 7 years old.
  2. High Back booster seats: High back booster seats include a seat under the child’s rear end, a back, and a headrest.  We recommend this type of booster seat for children who are at least 5 years old. This type of booster seat can often convert to a backless booster when the child is at least 7 years old.
  3. Combination car seats: Combination car seats work as a forward facing harnessed car seat, then convert to a high back booster, and sometimes convert to a backless booster.  We recommend this type of car seat for children who are at least 2 years old and have outgrown their rear facing convertible car seat.
  4. Multimode car seats: Multimode car seats have a few modes: rear facing harnessed mode, forward facing harnessed mode, high back booster mode, and sometimes a backless booster mode.

Families who are in the market for a new belt positioning booster for an older child are more likely to shop for a dedicated booster seat.  Families who bought combination or multimode car seats for younger children earlier may eventually plan to convert them into booster mode.

What the Rating Means

Peg Perego Viaggio HBB: 6 years old

Keep Calm and Booster On!

There are some things you need to consider before reading the evaluations.

  1. Keep Calm
  2. Don’t Panic
  3. As long as it fits your child correctly, keep using your booster for now, even if it’s not on the Best Bet list!

Change is Good

In 2009, not even a sixth of the boosters IIHS evaluated made the highest rating. This outside pressure on the industry caused rapid reform and improvement in belt fit. Today, almost all of the boosters on the market will provide an excellent fit on the 6 year old crash dummy.

The following list includes the newest additions to the IIHS booster rating. This list does not include many boosters on the market that have been rated in previous years by IIHS, but you can search for their ratings by brand.

Best Bets

Best Bets provided a good belt fit for almost all children in almost all vehicles.

These boosters provide good belt fit for typical 4 to 8 year old children in almost any car, minivan, or SUV.

Chicco GoFit
Cosco Finale combination car seat in high back booster mode
Cosco Finale DX combination car seat in high back booster mode
Diono Monterey XT booster seat in high back mode
Diono Monterey XT booster seat in backless mode
Evenflo Spectrum booster seat in high back booster mode
Evenflo Spectrum booster seat in backless mode
Graco Wayz combination car seat in high back mode
Graco Wayz combination car seat in backless mode
Maxi-Cosi RodiFix high back booster seat
Nuna AACE booster seat in high back mode
Nuna AACE booster seat in backless mode
Peg Perego Viaggio Shuttle backless booster seat


Check Fit

These boosters have varied results depending on child size and vehicle model.
Harmony Folding Travel Booster high back booster seat
Kiddy USA Cruiser 3 high back booster seat
Ride Safer Delighter backless booster


Not Recommended

This year’s list doesn’t have any Not Recommended seats.  A few models from previous years may still be around and available to buy.

It is worth looking at the list to make sure a booster you’re using or considering isn’t on this list. These boosters have demonstrated consistently poor belt fit.


Not reviewed: mifold

Booster substitute won’t be rated

This is news from last year but our feelings about the mifold’s inconsistent belt fit are so strong that we’re including this blurb again.

The mifold Grab-and-Go Booster is a highly portable belt-positioning device, but isn’t really a booster.

IIHS Summary

The vast majority of new booster seats earn the top rating of Best Bet in IIHS evaluations, but bad designs that fail to provide good belt fit continue to slip through.

The Takeaway

IIHS tests the fit against the Hybrid III 6 year old child crash test dummy.  While crash test dummies do an excellent job mimicking statistical generalities, they are not representative of individual children. A booster may not give a great fit on the dummy, or even on a particular real child, it might give a GREAT fit on your child, and that’s what matters.  Keep in mind this is NOT a crash test.  All boosters on the list have been self-certified as passing the stringent FMVSS 213 requirements for belt positioning boosters.

If you’ve read this article, reviewed the list of recommendations, examined your child’s booster fit, and realized that maybe it’s not ideal, you may consider purchasing another booster.  Review our list of recommended high back and backless boosters to organize your shopping list.

Do you have a question or concern about your booster?   First, fit your child’s booster correctly.  Then, keep using the booster seat you own, and make an appointment with a Child Passenger Safety Technician today to help evaluate the belt fit.