8.3 Occurrence vs. Claims-Made Triggers

How a Liability Policy Is Triggered

A coverage trigger is the event that activates a liability policy. The two competing approaches are the occurrence form and the claims-made form. The ISO CGL Coverage Form is published in both versions: CG 00 01 (occurrence) and CG 00 02 (claims-made). Knowing which form responds is essential because long-tail exposures (asbestos, pollution, products liability) can surface decades after the act.

• Occurrence trigger: Coverage applies if the bodily injury or property damage happens during the policy period, regardless of when the claim is filed — even years later.
• Claims-made trigger: Coverage applies only if the claim is first made against the insured during the policy period (or extended reporting period), and the injury occurred on or after the retroactive date.

Think of it as a question of timing. The occurrence form asks, "When did the injury happen?" The claims-made form asks, "When was the claim reported?" Most personal lines (HO, PAP) and the standard CGL are occurrence based, which is simpler for consumers because there is no retro date to track. Claims-made forms dominate professional liability (medical malpractice, D&O, E&O) and some pollution and products lines, where injuries may not surface for many years and insurers need to control "IBNR" (incurred but not reported) reserves.

The Claims-Made Timeline: Retroactive Date and ERP

Two dates control a claims-made policy:

1. Retroactive (retro) date — the earliest date an injury can occur and still be covered. Injuries before the retro date are excluded, even if the claim is made during the policy period. Advancing (moving forward) a retro date creates a dangerous coverage gap.
2. Extended Reporting Period (ERP) / "tail" — extends the time to report claims after the policy ends, for injuries that occurred during the policy period.

Why the Difference Matters — and Common Traps

Claims-made policies were created for long-tail exposures so insurers could reserve more accurately. A "long-tail" line is one where years pass between the negligent act and the manifestation of injury — asbestosis, latent construction defects, or a malpractice claim filed near the statute-of-limitations deadline. By tying coverage to the report date, the insurer always knows its open exposure within the current period rather than waiting decades for buried occurrences to surface. When an insured switches insurers or from claims-made back to occurrence, mismatched retro dates are the classic gap source. Tested traps include:

• A claim for an injury before the retro date is not covered, even though the claim is made during the policy term.
• Letting a claims-made policy lapse without buying tail coverage can leave the insured uninsured for past acts.
• An occurrence form responds based on when the injury happened, so an insured can have multiple occurrence policies triggered across years ("stacking" of policy periods).
• Claims-made premiums are typically lower in early (immature) years and rise as the policy "matures" toward the occurrence-equivalent fifth year.

A practical rule of continuity: when replacing one claims-made policy with another, the producer should keep the same retroactive date ("nose" coverage) so prior acts remain covered, or buy tail coverage on the expiring policy. The two are mirror images — a tail (ERP) extends reporting time on the old policy, while nose coverage on the new policy reaches back to the old retro date. Failing to do either leaves a gap precisely for the long-tail claims these forms exist to cover, and is a classic E&O exposure for the agent.

Coverage Triggers Defined

Liability policies use one of two triggers to decide which policy responds:

Retroactive Date and Reporting

A claims-made policy uses a retroactive date: events before that date are not covered, even if the claim is made during the policy. To prevent gaps when switching insurers or retiring, insureds buy an Extended Reporting Period (ERP) or "tail": a basic ERP (short, automatic, often 60 days) and a supplemental ERP (purchased, can be years or unlimited).

Why the Distinction Matters

Long-tail exposures (professional liability, pollution, products) often use claims-made because injuries surface years later, and insurers want to cap their "long tail." First-dollar general liability (CGL) is usually occurrence.

Worked Example

A consultant has a claims-made E&O policy with a retroactive date of 1/1/2023. A negligent act occurs in March 2024; a client sues in February 2026. If the consultant continuously renewed through 2026, the policy in force when the claim is first made (2026) responds, because the act (2024) is after the retroactive date. But if the consultant cancelled in 2025 and bought no tail, the 2026 claim is uncovered - the trap the exam highlights. The same loss under an occurrence policy would be covered by the 2024 policy regardless of when the suit arrived.