An ISO Rating is calculated based on the following criteria: Emergency Communication Systems (10 points); Fire Departments, covering personnel, capabilities, training, equipment, etc. (50 points); Water Supply (40 points); and Community Risk Reduction (extra credit of up to 5.5 points). Insurance premiums are not necessarily linked to ISO ratings. There are insurance companies that offer discounts for low PPC scores, but the rating structure is based on many factors and changes regularly. Insurers such as State Farm do not use ISO scores to calculate homeowner insurance premiums. ISO scores are only one of many criteria considered when discussing fire safety.