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What is an ISO Score &
Why Do They Matter?

A Deep Dive Series into the ISO Score and its Impact on Insurance Rates & Public Safety

Exploring the nuanced relationship between ISO Scores, insurance premiums, and public safety. Through research and case studies, we find that lower ISO scores don’t always equate to lower insurance rates. Join the discussion on the role of ISO scores in long-term planning.
Fire fighter filling out insurance paperwork for ISO scores.
Welcome to Alpine’s Insurance Services Office Score (“ISO Score”) and resulting Public Protection Classification (“PPC”) Blog Series.  We’ll be covering all things ISO – history, methods of calculation, scores by geography, and why it matters (or doesn’t).  While we hope this series is informative, our goal is to present facts and data that generate a discussion.  Tell us what we missed!

Why do ISO Scores matter?

If you are reading this, you are probably familiar with ISO scores.  How are ISO Scores generated? ISO scores come from Fire Suppression Rating Schedules (“FSRS”).  Click here for a link to the grading rubric.

The most common refrain from our customers is “Money”.  By money, they typically mean lower insurance premiums for constituents. However, after doing a lot of reading and talking to customers, the answer to if / why ISO scores matter may be “It Depends.” 

A review of different NFA research papers written by Chiefs in different states resulted in different answers (shocker). 

Monterey, CA Paper Findings

  • The North County Fire District lowered its ISO PPC from a 6 to a 4. Insurance rates did not go down.  In fact, in some cases, they went up. 
  • Private insurers use many data points to calculate costs beyond just ISO scores. For most insurers, prior claims and historical data play a larger role in determining rates than an ISO score. 
  • In some cases, insurers have dropped the use of ISO scores altogether (State Farm).
  • For other insurers, burglaries, thefts, wind, and water account for most of property insurance costs. Fire is a small part of the overall equation. 

Other papers by Pittman, Cannon, and Buchanan note the opposite – lower ISO scores equals lower insurance rates for taxpayers. 

What do you think? Are ISO scores an important part of your department’s long-term planning? Why or why not?