Glossary · Legal Concept
Severity (Insurance)
An insurance industry metric measuring the average dollar cost per claim within a given line of business, used by underwriters and analysts to track payout trends over time.
Also known as: claim severity, occurrence severity, loss severity
What it is
Severity is an insurance-industry metric that measures the average dollar cost per claim within a given line of business. It is distinct from "frequency," which measures how often claims occur. Together, frequency and severity drive the industry's understanding of underwriting profitability and reserve adequacy.
Why severity matters in medical professional liability
Medical professional liability is the most severity-pressured line in casualty insurance, with the highest occurrence-severity figure across all casualty lines (S&P Global Market Intelligence, 2025). A relatively small number of catastrophic verdicts and large settlements dominate the cost structure, even though most claims close with no payment or with modest amounts.
The accident-year immaturity problem
Malpractice claims take years to resolve. A case filed in 2023 may not produce a payout figure until 2027 or later. As a result, severity figures for recent accident years are systematically understated; they reflect only the early, pre-resolution slice of an open population. Anyone benchmarking a current case against recent severity numbers without adjusting for immaturity will underestimate the true trend.
In settlement strategy
Severity tracking is the working math of malpractice insurance. Plaintiff attorneys should benchmark against mature accident years adjusted to current dollars, not raw recent figures. Defense reserves anchored to recent severity figures will be too low. The Hooper Engine adjusts for accident-year maturity by weighting comparables differently based on resolution status.
See Also
- Accident Year — An insurance accounting convention that groups claims by the calendar year in which the underlying event occurred, regardless of when the claim was reported or paid.
- Loss Reserves — Funds an insurance carrier sets aside to pay anticipated future indemnity and defense costs on reported but unresolved claims.
- Medical Professional Liability — The insurance industry term for medical malpractice insurance and the broader category of professional liability claims against healthcare providers.
- Casualty Insurance — The broad category of insurance covering legal liability for losses caused to other persons or their property, including general liability, professional liability, workers' compensation, and auto liability.