What is a Manifestation Trigger


Breaking Down Manifestation Trigger

The manifestation trigger is an important concept in insurance because it sets the date of incident discovery as the date for coverage, not when the incident may have actually occurred. For example, if a winter storm knocks a tree on a homeowner’s house while the homeowner is on vacation, the triggering date for the policy is when the homeowner first detects and reports the accident, not the date the tree hit the house.


The three other types of insurance triggers are the exposure trigger, continuous trigger and injury-in-fact trigger. The exposure trigger uses the date when an injured party first came into harmful contact. The continuous trigger applies when damage or injury may have more than one trigger occurring at numerous points in time, while the injury-in-fact trigger applies on the date an injury or damage takes place.

What Happens When the Damage Is Not Discoverable?

Don's Building Supply in Texas sold exterior insulation and finish systems that were installed on various homes between December 1, 1993, and December 1, 1996. During construction, Don's was insured by three consecutive general liability policies issued by OneBeacon. Various homeowners filed suit against Don's from 2003 to 2005, alleging the insulation was defective and allowed moisture to seep inside, resulting in rot and other damage.

The homeowners argued the ongoing moisture exposure was damaging the homes and the damage began to occur on the occasion of first penetration of moisture, which was within six months to one year after application. The homeowners argued that the damage to the homes was hidden from view and not discoverable or readily apparent to someone looking at that surface until after the policy period ended. 

The case eventually went to the Texas Supreme Court. The issue, as paraphrased by the Supreme Court, was “is an insurer’s duty to defend triggered where damage is alleged to have occurred during the policy period but was inherently undiscoverable until after the policy period expired?” The answer was yes, the key date is when injury happens, not when someone happens upon it.