Experience modification is a rating factor that adjusts premium based on an employer’s actual loss experience compared with similar insureds. In plain language, it moves workers compensation pricing away from a pure class average and closer to the employer’s own claim record.
How the modifier works
The modifier is not just a simple count of claims. Rating plans usually:
- start with payroll and classification data
- calculate expected losses for the account
- compare expected losses with actual losses
- weight claim frequency and severity differently
- produce a factor that multiplies the manual premium
A modifier above 1.00 usually increases premium. A modifier below 1.00 usually lowers it.
Why insurers and employers care
The modifier affects both price and underwriting perception. A poor modifier can mean higher premium, harder renewal negotiations, and less market interest. A favorable modifier shows stronger safety performance and better control of claim costs than similar employers in the same classifications.
Because claim frequency often signals a recurring safety problem, multiple small losses can damage the modifier even when no single loss is catastrophic.
Practical example
Two contractors have similar payroll and governing classifications. One develops a 1.25 mod after repeated preventable injury claims. The other develops a 0.88 mod because losses are fewer and better controlled. Even if their operations look similar, the final premium can differ materially.