ISO is the principal provider of insurance underwriting, rating, and statistical information to the property and casualty insurance industry in the United States. ISO collects information about a community's public fire protection and analyzes the data using its Fire Suppression Rating Schedule which quantifies the community's fire suppression resources. Fire departments are evaluated on communications, water supply, personnel, training, and equipment. ISO then assigns a public protection classification (PPC) based on those resources, from Class 1 to Class 10, Class 1 represents the best public protection.

The formulas homeowner’s insurance companies use to determine their insurance rates are complex and constantly changing. But all other things being equal, a lower PPC score for your area may translate to a lower homeowner’s insurance premium, as it means your home is at a lower risk for serious fire damage. Home insurance companies may offer lower rates if you have a lower ISO rating.

However, how your rating impacts your homeowner’s insurance premium varies by insurer, and it's often only one of many factors it considers with regards to fire safety. For example, some companies will ask about your home's proximity to a fire station or fire hydrant, as well as whether you have a fire alarm or sprinkler system. Also, some insurers do not use ISO's score to set homeowners’ premiums at all. Instead, they use their own metrics based on factors like historical fire data.

The relationship between ISO PPC and insurance rates is complex. Based on experience and evaluation, the cost benefit of improving the District’s ISO PPC rating is in the best interest of the District and its patrons. The District went through an evaluation by ISO PPC in June of 2021. The results of that evaluation was the ISO rating being lowered.