ISO Catastrophe Loss Development

Catastrophe Experience for Homeowners Business Owners and Commercial Property

ISO's Catastrophe Loss Development is an Excel-based tool that gives you easy access to catastrophe-specific experience for homeowners, businessowners, and commercial property. The tool shows how historical development patterns can vary across different catastrophes — and between catastrophe and noncatastrophe circumstances.

Why you need ISO Catastrophe Loss Development

After a catastrophe strikes, insurers and reinsurers grapple with a common question: What will the cost to the company be?

But compiling and reporting accurate claims information takes time. So actuarial estimates always include a range of uncertainty, making reserve levels problematic.

ISO Catastrophe Loss Development helps insurers and reinsurers reduce that range of uncertainty.

ISO Catastrophe Loss Development can help you:

  • analyze and compare catastrophe data between catastrophes
  • examine trends in loss development and emergence patterns
  • view and compare loss data from a catastrophe with:
    • loss data from proximity areas unaffected by the catastrophe
    • loss data for the same geographic areas during a non-catastrophe period
  • compare a given catastrophe across states
  • view and compare loss experience by line and coverage

ISO used aggregate data from ISO's Property Claim Services (PCS) unit, ISO statistical data, and data from Multiple related sources e.g. National Climatic Data Center (NCDC), AIR, etc., to create the tool.

How it works

You access the tool at your workstation using a simple query screen. You can view the data by catastrophe, data type, data coverage, line of business, or state.

Just select the level of detail you wish to see:

  • line of business: homeowners, businessowners, and/or commercial property
  • data type: catastrophe data, noncatatastrophe data in a catastrophe period, or noncatastrophe
  • data in a noncatastrophe period
  • catastrophe: loss experience for specific catastrophes , beginning in 2004
  • coverage: buildings, contents, or buildings and contents (combined)
  • state: states affected by the catastrophe(s) you select
  • development: paid or incurred dollars

Once you make your selections, you can download your results as a graph or report.

Find out more

For more information on how ISO Catastrophe Loss Development can help your business, please send e-mail to