8.3 Occurrence vs. Claims-Made Triggers
Key Takeaways
- An occurrence policy covers injury or damage that HAPPENS during the policy period, no matter when the claim is reported.
- A claims-made policy covers a claim FIRST MADE during the policy period (or extended reporting period), subject to the retroactive date.
- The retroactive date bars coverage for injury that occurred before it; an incident before the retro date is never covered even if reported on time.
- Tail coverage (the Extended Reporting Period) covers late-reported claims after a claims-made policy ends; nose coverage (a prior-acts/earlier retro date) covers the gap on a new policy.
- Occurrence triggers create long-tail exposure (latent injuries); claims-made was designed for professional and pollution lines to limit that long tail.
The Two Coverage Triggers
A coverage trigger is the event that determines which policy period must respond to a claim. The Insurance Services Office (ISO) Commercial General Liability (CGL) program is written on two forms with two different triggers.
| Trigger | Coverage applies when... | ISO CGL Form |
|---|---|---|
| Occurrence | The bodily injury or property damage HAPPENS during the policy period | CG 00 01 |
| Claims-made | The CLAIM is first made during the policy period | CG 00 02 |
Occurrence Trigger
An occurrence policy responds to injury or damage that takes place during the policy term, regardless of when the claim is reported — even years later. This creates a long tail of exposure for latent injuries (asbestos, slow chemical exposure) where harm surfaces long after the policy expired.
Scenario: A product sold in 2024 causes injury discovered in 2030. The 2024 occurrence policy responds, because the injury "occurred" while that policy was in force - not the 2030 policy in force when the claim is filed.
Occurrence forms are standard for personal lines (homeowners and personal auto liability) and for the basic CGL because buyers value certainty that the policy in force at the time of an accident will pay, regardless of how slowly a claim develops.
Claims-Made Trigger and Its Key Dates
A claims-made policy responds to a claim first made against the insured during the policy period (or its extended reporting period), provided the injury happened on or after the retroactive date. Claims-made was developed for professional liability, directors & officers (D&O), and pollution lines to control the long tail.
The Retroactive Date
The retroactive date is the earliest date for which injury will be covered. Injury before the retro date is never covered, even if the claim is reported on time. A claim is covered only if BOTH: (1) the injury occurred on or after the retro date, AND (2) the claim is first made during the policy period or extended reporting period.
Extended Reporting Periods (Tail and Nose)
| Term | Function |
|---|---|
| Tail (ERP) | Covers claims reported AFTER a claims-made policy ends, for injuries during the covered period |
| Basic ERP | Short, automatic mini-tail (e.g., a 60-day report window) |
| Supplemental ERP | Purchased, longer tail for late-reported claims |
| Nose (prior acts) | A new policy with an EARLIER retro date covering the gap |
Why it matters: Without tail coverage, a professional who switches carriers or retires can be left with no coverage for a claim reported after the policy ended.
A claims-made policy has a retroactive date of January 1, 2024. An injury occurred in 2023 but the claim is first made in 2025 while the policy is in force. Is the claim covered?
Working a Timeline
Claims-made questions are best solved on a timeline. Place the retroactive date, the policy period, and any ERP, then plot the injury date and the claim date.
Worked example: A claims-made policy runs Jan 1, 2025 - Dec 31, 2025, retro date Jan 1, 2023.
- Injury Mar 2023, claim made Jun 2025 -> Covered (injury after retro date, claim during period).
- Injury Mar 2022, claim made Jun 2025 -> Not covered (injury before retro date).
- Injury Mar 2025, claim made Feb 2026 with no ERP -> Not covered (claim after the period ends, no tail).
Occurrence vs. Claims-Made: Quick Comparison
| Feature | Occurrence | Claims-Made |
|---|---|---|
| Trigger | Injury date | Claim date |
| Retroactive date | None | Yes |
| ERP/tail needed | No | Often yes |
| Premium maturity | Stable | "Steps up" years 1-5 |
| Common lines | CGL, personal lines | E&O, D&O, malpractice |
Exam takeaway: Occurrence = WHEN INJURY HAPPENS. Claims-made = WHEN THE CLAIM IS MADE, gated by the retroactive date, with tail coverage protecting late-reported claims.
Which statement best describes coverage under an occurrence-trigger liability policy?
Why the Trigger Choice Matters in Practice
The trigger choice shapes pricing, switching risk, and claim disputes.
Premium Maturity ("Step Factors")
Claims-made premiums start low and step up over roughly the first five years as the pool of reportable prior years grows, then level off at a mature rate. Occurrence premiums are stable from year one because each policy independently insures that year's occurrences.
| Year | Claims-made (steps up) | Occurrence |
|---|---|---|
| 1 (immature) | Lowest | Full |
| 2-4 | Rising | Full |
| 5+ (mature) | Level | Full |
Switching Carriers Without a Gap
When a professional changes insurers, coordination of the retroactive date prevents a gap:
- Tail (ERP) on the expiring policy covers claims reported after it ends for injuries during its term.
- Nose (prior acts) coverage on the new policy sets an earlier retroactive date so the new insurer picks up old injuries.
- Buying neither leaves the insured uninsured for any claim that surfaces after the old policy ends.
Long-Tail Disputes
Because occurrence forms respond by injury date, latent injury claims (asbestos, toxic exposure) can pull in policies from decades earlier and trigger disputes over which year's policy - or several years stacked - must respond. Claims-made was created precisely to avoid that uncertainty by tying coverage to the report date.
Exam takeaway: Occurrence = stable premium and long-tail exposure; claims-made = stepped premium, a retroactive date, and the need for tail or nose coverage when changing carriers or retiring.