The Public Adjuster's Guide to Anti-Concurrent Causation

If you ask a policyholder what "Concurrent Causation" means, they'll look at you blankly. If you ask a seasoned Public Adjuster, they will tell you it is arguably the most severe mechanism in modern property insurance.

While most adjusters focus on the "Perils Insured Against" section, the outcome of a complex loss is increasingly decided by the preamble to the Exclusions section.

The concept of Concurrent Causation, the principle that if two causes combine to produce a loss, and one is covered, the claim is covered, is increasingly being contractually overridden. To strictly manage this exposure, carriers have evolved their forms using the Anti-Concurrent Causation (ACC) Clause.

For Public Adjusters, ACC represents a structural risk: it fundamentally alters the burden of proof. If you miss this clause during intake, you may spend months building a sequencing argument for a claim that was technically dead the moment the loss occurred.

This guide covers the mechanics of the "Lead-In" clause, why "mostly covered" isn't enough, and the forensic strategies PAs use to preserve coverage.

1. The Anatomy of a Causation Override

Most exclusions are specific: "We will not pay for loss or damage caused by... Wear and Tear."

ACC clauses are structural. They reorder how the policy reads causation entirely.

Standard ISO language (Form CP 10 30) introduces the ACC provision with specific "Lead-In" language before the list of exclusions:

"We will not pay for loss or damage caused directly or indirectly by any of the following... Such loss or damage is excluded regardless of any other cause or event that contributes concurrently or in any sequence to the loss."

The Trap: In jurisdictions following Efficient Proximate Cause, if a covered peril (Wind) and an excluded peril (Flood) destroy a building together, the wind damage is often covered. However, without ACC, the fight is fair; with ACC, the fight is heavily skewed.

Under an ACC clause, the presence of the excluded peril poisons the entire well. The clause explicitly kills the "sequence" argument—it does not matter which peril happened first.

2. The "90/10" Math

A persistent misconception among newer adjusters is that if the covered peril caused most of the damage, the claim is safe.

ACC destroys this logic. In jurisdictions that strictly enforce these clauses, the percentage of contribution is irrelevant.

Case in Point: In a Colorado case involving a roof collapse, a jury determined that 90% of the damage was caused by the weight of snow (a covered peril). Only 10% was attributed to excluded causes. Yet, because the policy contained ACC language, the court denied coverage for the entire loss.

The Takeaway: You cannot rely on a "majority rules" argument. If the carrier can credibly point to an excluded cause in the chain, even 1%, they can leverage ACC for a total denial; to survive an ACC denial, you must prove that the damages are effectively two separate losses rather than one concurrent loss.

3. The Definition Expansion: Water vs. Earth

We are seeing a rise in ACC denials that combine "Water" exclusions with broad "Earth Movement" definitions to swallow standard losses.

As discussed in recent industry analysis of Federal District Court decisions like Lawrence v. State Farm, a burst pipe (covered) released 200,000 gallons of water, eventually causing the foundation to shift (earth movement).

• The policy defined earth movement to include shifting "regardless of whether combined with water".
• Because ACC language applied to the earth movement exclusion, the court upheld the denial, even though the water release was sudden and accidental.
• This same logic was applied in Dalmac Realty LLC v. Scottsdale Insurance Company, where a burst pipe caused soil erosion and collapse. The court ruled that the ACC clause barred coverage "regardless of any other cause", including the broken pipe, that contributed to the loss.

4. Segregation of Damages: The Tactical Counter

If you are facing an ACC policy, relying on state case law is risky. While states like New York and New Jersey are currently debating legislative bans on ACC, relying on pending legislation won't save a current claim. Some jurisdictions still analyze losses through an "efficient proximate cause" lens, while federal courts in other districts may strictly enforce the contract.

Your strongest leverage is often Segregation of Damages (supported by forensic engineering). To survive an ACC denial, you must prove that the damages are effectively two separate losses rather than one concurrent loss.

• The Strategy: Do not submit a global estimate that blends damages. You need forensic engineering reports that draw a bright line, physically and temporally, between the covered and excluded damage.
• The Precedent: Courts have held that if damage from a covered event (like rainwater intrusion) creates a distinct, segregable loss from the excluded event, coverage may apply to that specific portion.
• The Burden Shift: In some favorable venues (like Florida), courts have recognized (in certain exclusion disputes) that once you prove a loss occurred during the policy period, the burden may shift to the insurer to prove an excluded cause was the sole or efficient cause. Segregating the scope forces them to prove the negative on each line item.

5. Strategy Lock-In: The Intake Risk

The real danger of Anti-Concurrent Causation isn't just losing in court; it's losing at file setup. If a PA writes an initial scope or Notice of Loss that casually mentions "water entered through the floor" alongside wind damage, they may have locked in a denial before they even realized ACC was in play.

6. The Intake Checklist: 8 Questions in 8 Minutes

Don't wait for the denial letter to realize the causation language is against you. Run this checklist at intake to determine if you are fighting a fair fight or a rigged one.

1. The Lead-In: Does the policy preamble contain "concurrently or in any sequence" language?
   • Impact: Identifies whether the presence of any excluded peril can contractually bar coverage for the entire loss.
2. The "1%" Contributor: Is there evidence of any excluded cause (e.g., wear and tear, surface water)?
   • Impact: In strict ACC jurisdictions, even a minimal excluded contribution can result in a total denial.
3. Earth/Water Trap: Does the "Earth Movement" definition exclude coverage regardless of water contribution?
   • Impact: Identifies the Lawrence trap where covered water losses are denied because they allegedly triggered ground movement.
4. Jurisdiction: Is the loss in an "Efficient Proximate Cause" state or a strict ACC state?
   • Impact: Determines whether efficient proximate cause arguments are viable or whether you must immediately pivot to segregation.
5. Segregation Capability: Can a forensic engineer physically and temporally separate the covered damage from the excluded?
   • Impact: This "bright line" separation is often your only survival strategy in ACC disputes.
6. Burden Shifting: Does the venue shift the burden to the carrier to prove the exclusion (e.g., Florida)?
   • Impact: If yes, segregating the scope forces the insurer to prove the exclusion on each specific line item.
7. Form Type: Is this a standard ISO form (CP 10 30) or a proprietary carrier form?
   • Impact: Proprietary forms often hide ACC language in the "Definitions" section rather than the "Exclusions" lead-in.
8. Narrative Discipline: Did the initial Notice of Loss inadvertently mention a concurrent excluded cause?
   • Impact: Prevents "Strategy Lock-In" where a casual mention of "flood" or "rot" kills the claim before you are hired.

Diagnostic Rule: If you answer "yes" to questions 1–3 and "no" to questions 5–6, you are likely walking into a structurally dead claim unless the narrative is tightly controlled from day one.

Why This Matters for Policy Analysis

Anti-Concurrent Causation is a "hidden exposure" in policy language—often buried in the preamble to the exclusions or hidden within specific definitions like Earth Movement. A standard keyword search for "Wind" or "Water" will completely miss the structural override that makes the entire claim vulnerable to a 1% excluded contributor.

Public Adjusters use Frontera to surface these "Lead-In" clauses and causation traps immediately—distinguishing between a standard exclusion and a total coverage bar before drafting the initial narrative.

References

• Colo. Intergovernmental Risk Sharing Agency v. Northfield Ins. Co., 2008 WL 2837517 (Colo. App. 2008)
• Lawrence v. State Farm Fire & Cas. Co., No. 5:24-cv-04008 (N.D. Iowa 2025)
• Dalmac Realty LLC v. Scottsdale Ins. Co., No. 3:24-cv-00942 (D. Conn. Oct. 30, 2025)
• Atl. Mut. Ins. Cos. v. Lotz, 384 F. Supp. 2d 1292 (E.D. Wis. 2005); Corban v. United Servs. Auto. Ass'n, 20 So. 3d 601 (Miss. 2009)
• Jones v. Federated Nat'l Ins. Co., 235 So. 3d 936 (Fla. 4th DCA 2018)