Glossary

Concurrent causation

The question of how to decide coverage when a covered cause and an excluded cause combine to produce one loss, such as wind and storm surge in a hurricane.

Also called: concurrent cause doctrine, multiple causes of loss, concurrent causes

Concurrent causation arises when two or more causes combine to damage a home and at least one is covered while another is excluded. A hurricane is the textbook case: wind tears the roof open, storm surge floods the ground floor, and the policy covers wind but excludes flood. Who pays for damage both causes touched?

Courts have answered differently. Under a concurrent-cause rule, coverage may exist if a covered cause independently contributed to the loss. The efficient proximate cause approach asks which cause was dominant. A third approach enforces the policy as written, and many policies are written to defeat concurrent-cause arguments (see anti-concurrent causation clause). Which rule applies depends on your state, the policy wording and the facts.

Say wind rips off shingles and rain soaks the bedroom ceiling, and later a creek overflows and ruins the ground-floor flooring (hypothetical). Those are separate losses with separate causes, and the insurer should pay the wind part. Disputes happen where the damage overlaps. Dated photos, weather data and an engineer's report on the sequence of events often decide them. See wind vs water: the hurricane claim dispute and engineering reports and causation disputes; for state-specific questions, an attorney or your state insurance department is the place to start.

Last reviewed October 10, 2026

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Related terms

Anti-concurrent causation clause Exclusion wording that denies a loss whenever an excluded cause contributes, even if a covered cause also played a part or came first. Efficient proximate cause A legal test that decides coverage by asking which cause set the others in motion and dominated the loss when covered and excluded causes combine. Exclusion A policy provision that removes coverage for a stated cause, type of loss, property or circumstance that the coverage would otherwise reach. Peril A specific cause of loss, such as fire, wind, theft or water, that a policy covers or excludes; it is the cause of the damage rather than the damage itself. Storm surge The abnormal rise of seawater that a hurricane or strong storm pushes onshore above the normal tide, treated as flood and excluded from homeowners policies. Windstorm The peril of damage from high winds, including hurricanes, tornadoes and thunderstorm gusts, which most policies cover, sometimes with a separate deductible.

Related guides

Anti-concurrent causation clauses explained One policy sentence can bar a whole loss if an excluded cause like flood played any part. How it works, which states limit it, and how to document a claim. Claims for hidden damage discovered later Can you claim damage found months after a storm, leak or fire? What decides it: cause, timing, late-notice rules, deadlines that run from the loss, and proof. Engineering reports and causation disputes When insurers and homeowners hire engineers, what causation reports contain, how to challenge one, and how to commission your own in a disputed home claim.