What is the effect of an anti-concurrent causation (ACC) clause?

The anti-concurrent causation (ACC) clause is a provision commonly found in certain insurance policies. Its primary effect is that it eliminates coverage for a loss if there are multiple causes for that loss, and one of those causes is not covered by the policy. In situations involving catastrophic events, such as a natural disaster, if the cause of the loss includes a peril that is specifically excluded in the policy, then even if other covered perils contributed to the loss, the claim may be denied due to the presence of the excluded peril.

For example, if a flood causes damage to a home but the policy does not cover flood damage, and there is also wind damage that is covered, the ACC clause would allow the insurer to deny the claim. The logic is that because one cause (flood) is excluded, coverage for the entire loss is eliminated, irrespective of other concurrent causes.

Thus, the correct option about the effect of an ACC clause accurately reflects the reality of how such clauses operate in insurance contracts, and demonstrates the importance of understanding the nuances of policy language when assessing coverage in complex scenarios.