occurrence vs claims-made coverage
/ uh-KUR-ents; claims-made /
Imagine a doctor's mistake in 2026 that the patient only notices and sues over in 2031. Which year's insurance policy should pay — the one in force when the harm happened, or the one in force when the claim was made? Liability claims can surface years after the act that caused them, so insurers had to choose a rule for which policy 'catches' such a delayed claim. Occurrence and claims-made are the two answers.
An 'occurrence' policy responds to events that occur during its period, no matter when the claim is reported — the 2026 policy pays the 2031 lawsuit, because the harmful act occurred in 2026. A 'claims-made' policy instead responds to claims first made during its period (for acts after a stated retroactive date) — so it is the policy in force in 2031 that pays, provided the doctor kept claims-made coverage continuously. Claims-made policies were invented for 'long-tail' lines like medical malpractice and professional liability, where occurrence coverage forced insurers to estimate decades of unknown future claims on a single year's premium.
This choice is one of the most consequential in P&C. Occurrence coverage is simpler for the buyer but harder to reserve (the insurer is exposed to claims that may emerge for decades, the dreaded 'long tail'). Claims-made limits the insurer's tail but creates two traps for the buyer: at the start, prior acts may be uncovered unless you backdate the retroactive date; and at the end, if you stop renewing (retire, switch insurers), you need 'tail coverage' (an extended reporting period) or claims made after you stop are uncovered. The misconception to avoid: claims-made does not mean 'cheaper for the same protection' — it shifts where the gap can open, and missing the tail can leave a retiring professional dangerously exposed.
A surgeon's error in 2026 leads to a lawsuit filed in 2031. Under an occurrence policy, the 2026 policy pays. Under claims-made, the 2031 policy pays — and if the surgeon retired in 2030 without buying tail coverage, no policy responds and the surgeon pays personally.
Occurrence pays by when the act happened; claims-made pays by when the claim is reported.
Claims-made is not just 'occurrence made cheaper' — it moves where coverage gaps can open. Watch the retroactive date at the start and buy tail coverage at the end; otherwise late-reported claims fall through the cracks.