Policy language that allows your insurance company to deny a claim if any excluded cause contributed to the loss — even when a covered storm event like hail or wind was also a factor.
What an Anti-Concurrent Causation Clause Is
An anti-concurrent causation (ACC) clause is policy language that gives your insurance company the right to deny a claim entirely if an excluded cause — such as normal wear and tear, poor maintenance, or deterioration — played any role in the loss, even if a covered cause like hail or wind was the primary factor.
In plain terms: if your roof was already aging and a hailstorm hits it, a carrier with an ACC clause may argue that because wear and tear contributed to the damage, the entire claim is excluded. Not reduced. Denied.
It is one of the most powerful tools carriers use to deny claims on older roofs in Colorado — and one of the least understood provisions in a standard homeowner’s policy.
How an ACC Clause Works in Practice
Without an ACC clause, a carrier evaluating a roof with both storm damage and pre-existing wear would typically cover the storm damage and apply depreciation for the roof’s age and condition. The homeowner gets paid — less than on a new roof, but paid.
With an ACC clause, the carrier can take a different position: because wear and tear — an excluded peril — contributed to the loss alongside hail — a covered peril — the entire claim is excluded. The concurrent presence of any excluded cause potentially voids the entire claim.
This is why ACC clauses are particularly impactful in Colorado, where roofs in the hail corridor frequently have some degree of age-related wear before a storm hits.
How to Identify an ACC Clause in Your Policy
ACC clauses are typically buried in the exclusions section of your policy. The language varies by carrier but generally follows one of these patterns:
- “We do not insure for loss caused directly or indirectly by any of the following…”
- “Such loss is excluded regardless of any other cause or event that contributes concurrently or in any sequence to the loss…”
- “Loss caused by or resulting from [excluded peril] is not covered even if another cause of loss that is covered contributes to the loss…”
The phrases “concurrently,” “in any sequence,” and “regardless of any other cause” are the key indicators. If you see that language in your exclusions section, your policy includes an ACC clause.
ACC Clauses and Colorado Law
Colorado courts have addressed anti-concurrent causation clauses in ways that offer meaningful — though not absolute — protection to policyholders.
The Efficient Proximate Cause Doctrine
Colorado recognizes the efficient proximate cause doctrine, which holds that when a covered peril sets a chain of events in motion that results in a loss, coverage applies even if excluded perils contributed along the way. In practical terms, if hail was the dominant cause that triggered the loss, Colorado courts have in some cases required coverage despite ACC language in the policy.
Not a Guaranteed Defense
The efficient proximate cause doctrine is not a blanket override of ACC clauses in Colorado. Whether it applies depends on the specific facts of your claim, your policy language, and how the loss occurred. It is a legal argument — not a simple rule — and outcomes vary. If your carrier is invoking an ACC clause to deny your claim, this is a situation that warrants professional review.
Policy Language Still Controls
Colorado courts have also upheld ACC clauses in some cases where the policy language was clear and unambiguous. The strength of your position depends heavily on how the clause is written and how the damage occurred. There is no universal answer — which is why the specific facts matter.
ACC Clauses on Older Colorado Roofs
The combination of Colorado’s hail frequency and its aging housing stock makes ACC clauses a significant practical issue for Front Range homeowners. A roof that is 15 or 20 years old almost certainly has some degree of wear — which gives a carrier with an ACC clause a potential foothold to deny a hail damage claim.
This is one of the reasons that establishing clear causation — documenting that storm damage is identifiable, specific, and distinct from pre-existing wear — matters so much on older roofs. The stronger your causation evidence, the harder it is for a carrier to make a credible concurrent causation argument.
What to Do If Your Carrier Invokes an ACC Clause
Receiving a denial that cites concurrent causation or an ACC clause is not necessarily the end of your claim. Here is how to approach it:
- Request the adverse action letter — get the denial in writing with the specific policy language cited
- Read the exact ACC language in your policy — the specific wording matters significantly for determining your options
- Get a professional inspection focused on causation — documentation distinguishing storm damage from pre-existing wear directly challenges the concurrent causation argument
- Research Colorado’s efficient proximate cause doctrine — if hail was the dominant cause of your loss, this legal doctrine may support your claim despite ACC language
- Consult a Colorado insurance attorney — ACC clause denials are legal disputes, not just documentation disputes. An attorney familiar with Colorado bad faith law can assess whether your carrier’s position holds up
- Consider invoking the appraisal clause — if the dispute is about damage value rather than coverage entirely, appraisal may still be available even when an ACC clause is cited
How ACC Clauses Differ From Standard Exclusions
A standard exclusion removes a specific type of damage from coverage — normal wear and tear, for example, is excluded because insurance is designed to cover sudden losses, not gradual deterioration. That is a reasonable and expected limitation.
An ACC clause goes further. It uses the presence of an excluded cause to eliminate coverage for the covered cause as well. A standard exclusion reduces what you can claim. An ACC clause can eliminate the claim entirely based on the co-existence of any excluded factor — even a minor one.
That distinction is why ACC clauses are among the most consequential provisions in a homeowner’s policy, and why knowing whether your policy contains one matters before you file a claim.
Common ACC Clause Questions
Does every Colorado homeowner’s policy have an ACC clause?
No. ACC clauses are common but not universal. Open peril policies vary significantly in whether and how they include ACC language. Reading your specific policy — particularly the exclusions section — is the only way to know. If you’re unsure, ask your agent to point you to the concurrent causation language specifically.
Can an ACC clause be used to deny any hail claim on an old roof?
Carriers may attempt this, but it is not automatically a valid position in Colorado. The efficient proximate cause doctrine, combined with strong causation documentation, can counter an ACC-based denial when hail was the clear primary cause of the loss. The strength of that argument depends on the facts and the specific policy language.
Is there anything I can do before a storm to protect against an ACC clause denial?
Yes — document your roof’s condition before storm season with dated photos and a professional inspection report. If your roof is in good condition before a storm and damaged after it, that documentation directly undermines a pre-existing damage argument. It also establishes a clear before-and-after baseline that makes causation much easier to prove.
Can I remove an ACC clause from my policy?
Generally no — ACC clauses are standard policy provisions, not optional endorsements. What you can do is shop for a policy that does not include one, or work with an independent agent who can review policy language across multiple carriers before you purchase or renew.
How Claim Advocacy Helps With ACC Clause Denials
Anti-concurrent causation denials are among the most complex disputes in residential roof claims. They sit at the intersection of policy interpretation, causation documentation, and Colorado insurance law — which is exactly why having professional support matters.
- Causation documentation — a professional inspection report that clearly distinguishes storm damage from pre-existing wear removes the factual basis for a concurrent causation argument
- Policy language review — identifying whether the ACC clause in your specific policy actually applies to your situation, and whether Colorado’s efficient proximate cause doctrine offers a counter-argument
- Denial response strategy — knowing whether to pursue re-inspection, appraisal, DOI complaint, or legal action based on the specific denial language
- Attorney referral — for ACC clause denials that require legal action, connecting you with a Colorado insurance attorney familiar with bad faith claims
Related Glossary Terms
- Concurrent Causation
- Causation
- Exclusion
- Denial
- Adverse Action Letter
- Pre-Existing Condition
- Open Peril Policy
- Bad Faith
- Colorado Division of Insurance (DOI)
Need Help With an ACC Clause Denial?
An anti-concurrent causation denial is one of the more aggressive positions a carrier can take — and in Colorado, it is not always a position that holds up. If your claim was denied because the carrier cited concurrent causes, a professional review of the denial language and your documentation is a worthwhile first step.
📞 Call to discuss your claim: (719) 210-8699
📧 Email: gerald@winik.io