What Is A Loss Run? Definition, Purpose, And How Underwriters Use It

Loss Run A record of prior insurance claims and losses, commonly requested during underwriting or renewal. Loss runs are chronological summaries prepared by insurers that list every claim made on a policy over a specified period (typically three to five years), including dates, amounts paid, reserved amounts, loss descriptions, and claim status. Underwriters, brokers, and risk managers use loss runs to judge an insured’s loss history, estimate future exposure, set pricing, and decide whether to accept or modify coverage terms.

When a carrier asks for a loss run, they want a compact, verifiable history of how frequently and how severely an insured has experienced losses. A good loss run isolates trends (repeat causes, single large losses, or many small claims) faster than a stack of individual claim files. For brokers and procurement teams, loss runs are the first document carriers examine after the application — often before a physical inspection or payroll verification.

What The Report Typically Contains

Loss runs standardize the claim information insurers need for underwriting. Typical fields include:

• Date Of Loss: The incident date that generated the claim.
• Claim Number: Carrier-assigned identifier linking to claim files.
• Reported Date: When the claim was first reported to the insurer.
• Paid Amount: Total paid to date on the claim.
• Case Reserves: Current reserve amounts set aside for open claims.
• Loss Description: Short narrative of the cause and circumstances.
• Coverage Line: Which policy line the claim affected (GL, Auto, Property, WC, etc.).

Why Loss Runs Matter To Underwriting

Loss runs convert claims history into actionable underwriting inputs. Underwriters use them to:

• Assess Frequency And Severity: Frequent small losses may indicate control failures; a single catastrophic loss may signal isolated risk or systemic exposure.
• Set Pricing And Terms: Historical loss patterns influence premium, deductibles, sublimits, and exclusions.
• Determine Eligibility: Certain industries or loss trends can trigger declinations or referrals to specialty markets.
• Estimate Retentions: For self-insured or captive programs, loss runs help calculate expected loss costs and required reserves.

How Loss Runs Vary By Line And Provider

Format and detail in loss runs differ between carriers and policy lines. A commercial auto loss run often lists accident details, bodily injury and property damage payouts, and whether a driver was at fault. Workers’ compensation loss runs emphasize injury descriptions, days lost, and indemnity vs medical splits. Some carriers produce compact, one-line-per-claim summaries; others include richer narratives and status notes. Third-party data vendors also aggregate loss runs into standardized feeds used by large underwriters.

Who Requests And Who Provides Loss Runs

Brokers request loss runs from incumbent carriers on behalf of insureds during renewal or when seeking new quotes. Prospective carriers request them to underwrite new policies. Employers, business owners, and risk managers are the common requestors. Carriers are contractually obligated in many jurisdictions to provide loss runs within a specific timeframe (for example, within 15–30 days) when requested by the insured or the insured’s agent — check state insurance department rules for exact timelines.

Practical Example: A Three-Provider Renewal

A medium-sized manufacturing firm seeks renewal quotes. The broker orders loss runs from the incumbent general liability and workers’ compensation carriers covering the last five years. Carrier A’s loss run shows two small slip-and-fall claims and one property loss with a partial recovery; Carrier B’s workers’ comp run shows a cluster of repetitive strains with escalating medical severity; Carrier C’s loss run is clean. Underwriters price the accounts differently: Carrier A offers renewal with modest premium increase; Carrier B seeks elevated deductibles or a safety improvement plan; Carrier C quotes a competitive rate but asks for loss-control confirmation before binding.

Tips For Preparing And Reviewing Loss Runs

• Request Early: Ask for loss runs 45–60 days before renewal to allow time for corrections and carrier review.
• Check For Errors: Reconcile claim dates, paid amounts, and whether closed claims remain open; incorrect reserves can skew renewal pricing.
• Document Recoveries: If subrogation paid part of a loss, ensure recoveries are recorded to reduce net severity.
• Provide Context: Attach short narratives or corrective-action summaries for recurring causes (e.g., “implemented new machine guard in 2024”).
• Use Standard Formats: When possible, request or supply ACORD-style or CSV exports to ease carrier ingestion and comparison.

In short, the Loss Run is a foundational underwriting document that condenses an insured’s historical claims into a format carriers use to evaluate risk, set pricing, and recommend controls. Accurate, timely loss runs shorten renewal cycles, reduce surprise exposures, and help brokers present a clearer risk picture to competing markets.