Pricing Workers' Compensation Insurance

Rating Structure

Workers' compensation insurance pricing is built on a class code system maintained by the National Council on Compensation Insurance (NCCI) or independent state rating bureaus. Each class code has a base rate reflecting the historical loss experience for that occupation category. The premium for a policy equals the sum of each class code's rate multiplied by the corresponding payroll divided by 100. Large accounts receive experience modifications (experience mods) based on their own loss history, adjusting premiums up or down relative to the class average. Retrospective rating plans further adjust premiums after the policy period based on actual losses.

Key Actuarial Challenges

Workers' compensation involves long-tailed liabilities, particularly for permanent disability and medical benefits that may extend decades. Loss development patterns are among the longest in property-casualty insurance. Actuaries must account for medical cost inflation, legal environment changes, and benefit level adjustments mandated by state legislatures. The interaction between first-dollar coverage and deductible programs (common for large employers) adds complexity. Loss cost trending requires separate analysis of frequency and severity trends, as these often move in different directions.