Workers' compensation cost containment begins with loss control and safety fundamentals. The frequency of accidents — how many occur per hours worked, payroll, or days — is a much better safety indicator than the severity of any single injury. 
Theoretically, if a company has many accidents it is only a matter of time before a bad or catastrophic claim occurs; one isolated injury can be bad luck, but repeated accidents signal underlying problems. For related workplace risk guidance see Understanding Premises Liability and Workers' Compensation Insurance.
Personal protective equipment (PPE) is primarily designed to reduce the severity of injuries, while safety training, job ergonomics, and employee awareness tend to reduce frequency. Reducing frequency through training and hazard control usually has the greatest impact on workers' compensation costs.
The experience rating formula reflects these philosophies by comparing expected losses to actual losses and setting a modification as a variance from that norm. For an overview of how expected losses relate to premiums and rates, see Workers' Compensation Insurance Overview.
The standard exposure unit for workers' compensation is payroll measured in one hundred dollar increments. Insurers compare historical losses for an industry to historical payrolls to determine a rate of loss per one hundred dollars of payroll, then apply a severity discount to expected losses.
Actual losses below a state-specific severity threshold are added together, while severe claims above that threshold are individually discounted on a scale up to a state maximum. Those discounted large losses are combined with the smaller losses to produce the actual loss amount, which is compared to the theoretical expected losses using a three-year historical period.
The resulting actual-over-expected ratio becomes the experience modification. A modification above 1.00 indicates worse-than-average loss experience and higher cost, while a modifier below 1.00 indicates better-than-average performance. For example, a company with a 1.15 modification pays fifteen percent more than the average competitor and forty‑three percent more than a competitor with a 0.80 modification.
Lowering frequency through training, ergonomics, and awareness not only reduces workers' compensation costs but also lowers labor cost, improves employee satisfaction, and can provide a competitive edge. If you want a tailored estimate or to review your options, talk to an agent.
Frequently Asked Questions
How does reducing accident frequency affect my premium?
Reducing frequency lowers the number of claims, which generally improves your experience modification and can reduce premium costs over time.
What is an experience modification factor?
It is a ratio of actual losses to expected losses over a set period; a number above 1.00 increases cost, while below 1.00 reduces it.
Why is payroll used as the exposure unit?
Payroll is a practical proxy for exposure because it correlates with the amount of labor and time at risk across an industry and employer size.
What practical steps lower my experience modification?
Implement safety training, improve job ergonomics, maintain thorough incident reporting, and manage claims actively to reduce frequency and claim costs.