What type of claim requires proof that the policy was active at the time of the event?

A claims-made claim specifically requires proof that the insurance policy was active at the time the claim is made, as well as that the event leading to the claim occurred after the policy was in force. This type of claim structure is important in various types of professional liability insurance, where coverage is often contingent upon both the occurrence of a covered event and the existence of an active policy when that event is reported.

In contrast, an occurrence claim typically covers events that happen during the active policy period regardless of when the claim is actually made, as long as the event occurred when the policy was in effect. Endorsement claims refer to adjustments or modifications made to an existing policy rather than initial coverage. Liability claims are broad and can encompass various types of incidents; however, they do not inherently require the same proof of active coverage based on the timing of the claim. Thus, in the context of the question, the claims-made claim stands out due to its specific requirements regarding the timing of both the event and the policy coverage.