Commercial General Liability (CGL) Forensic Audit: Occurrence vs. Claims-Made Policy Triggers

1. Occurrence Form Architecture & The Indefinite Reporting Horizon

Under standard ISO CG 00 01 occurrence coverage, policy protection is triggered solely by the physical manifestation of bodily injury or property damage taking place during the active policy term. Crucially, the actual lawsuit or claim may be asserted years—or decades—after the policy has expired.

This architecture is vital for construction defect, environmental pollution, and occupational toxic tort exposures where damages manifest slowly over prolonged intervals. Provided the damage occurred while the policy was in force, the carrier remains legally obligated to defend and indemnify the insured up to policy limits.

2. Claims-Made Mechanisms & The Retroactive Date Trap

Claims-made forms, commonly utilized in professional liability (E&O), directors & officers (D&O), and cyber insurance, require two simultaneous conditions: the wrongful act must occur on or after a specified Retroactive Date, and the claim must be officially reported to the carrier during the active policy term.

If an insured changes carriers and the successor underwriter advances the retroactive date to the inception of the new policy, an immediate coverage void is created for all prior operations. This trap has resulted in devastating uncovered legal verdicts across engineering firms and medical practices.

3. Defense Costs: Inside vs. Outside Limits

In standard ISO general liability policies, the insurer’s duty to defend is broader than its duty to indemnify, and defense costs are paid outside the limits of liability. A policy with a $1,000,000 occurrence limit provides full legal defense without exhausting the available indemnity pool.

Conversely, specialized manuscript policies frequently incorporate defense expenses inside limits (self-eroding policies). In complex litigation where legal defense expenditures reach $450,000, the remaining limit available to satisfy a court judgment is eroded down to $550,000, creating severe personal asset exposure for policyholders.

4. Extended Reporting Periods (Tail Coverage) Valuation

Upon termination or non-renewal of a claims-made policy, purchasing an Extended Reporting Period (ERP or tail endorsement) is mandatory to protect against latent liabilities. Supplemental ERP endorsements typically cost between 150% and 300% of the expiring annual policy premium, providing an indefinite or multi-year window to report claims arising from pre-expiration activities.