Insurance denials look infinitely varied when you are the one receiving them, but they are not. They cluster into a small number of recurring categories, and the category determines everything about what you can do next.
Below are the twelve you are most likely to encounter, what each one means, and what kind of response fits it. Some are difficult to challenge. Others frequently turn on a factual question with a documentable answer.
1. The event is excluded
The policy does not cover this type of loss at all. Flood under a standard homeowners policy. Earth movement. Intentional acts. War. Nuclear hazard.
What fits: check whether the exclusion has a carve-back. Many do — language saying the exclusion does not apply in specified circumstances, or that resulting damage is still covered. Also check whether the loss is being characterized correctly. Water that entered from outside at ground level is flood; water from a failed supply line inside the house generally is not, though the visible result can look identical.
2. Wear, tear, and gradual deterioration
Property policies cover sudden, accidental events. They do not cover things aging. A roof at the end of its service life, a slowly corroding pipe, foundation settling over years.
What fits: this is a factual dispute, and factual disputes are answered with expert documentation. A licensed contractor or engineer stating that a component failed suddenly, with the physical evidence described, addresses the reasoning directly. Maintenance records help.
3. Anti-concurrent causation
Two causes combined to produce the damage, one covered and one excluded. The provision says that when that happens, the whole loss is excluded — regardless of which cause contributed more.
What fits: the argument usually concerns whether the causes were genuinely concurrent, or whether the damage can be separated. States differ considerably in how they enforce these clauses, and a few limit them. This is one of the categories where legal advice in your state matters most.
4. Late notice
The policy requires prompt reporting. The insurer says you did not report promptly enough.
What fits: two questions. First, whether the delay was actually unreasonable given when you discovered the loss — hidden damage discovered later is a different situation from damage you saw immediately. Second, whether the delay prejudiced the insurer's ability to investigate. Many states require that showing before late notice can defeat a claim.
5. Failure to mitigate
Policies require you to take reasonable steps to prevent further damage after a loss. If you left a broken window open through a week of rain, the additional damage may not be covered.
What fits: document what you actually did and when. Receipts for tarps, boarding, water extraction, emergency plumbing. The duty is to act reasonably, not perfectly.
6. No proof of loss, or an incomplete one
Many policies require a sworn proof of loss within a stated period after the insurer requests it — frequently 60 days. Missing it can be treated as a breach of a policy condition.
What fits: if the deadline has not passed, submit it. If it has, ask whether the insurer waived the requirement through its conduct, which is a recognized argument in many states, particularly where the insurer continued to handle the claim without objection.
7. Material misrepresentation on the application
Information given when the policy was bought was inaccurate, and the insurer says the inaccuracy mattered.
What fits: the standards vary widely by state and by insurance type. Some states require the insurer to show the misstatement was intentional; others require only that it was material. Contestability periods also matter — after a certain time, many policies limit the grounds on which they can be challenged. This category usually warrants professional advice.
8. The policy was not in force
Non-payment lapse, a cancellation effective before the loss, or coverage that had not yet started.
What fits: this is documentary. Payment records, bank statements, and the notice the insurer was required to send before cancelling. Most states have specific requirements about how and when a cancellation notice must be delivered, and a defective notice is a real issue.
9. Not medically necessary
A health plan's term for treatment it says is not required for your condition according to its clinical criteria.
What fits: ask for the specific criteria applied and the credentials of the reviewer. A letter of medical necessity from your treating physician that engages with those criteria directly — rather than restating the diagnosis — is what an internal appeal is built on. If the internal appeal fails, external review by an independent organization is available for most plans.
10. Out of network, or no prior authorization
Administrative rather than clinical: the provider was outside the network, or a required approval was not obtained beforehand.
What fits: check whether an exception applies. Emergency care is treated differently under federal law, and the No Surprises Act limits balance billing in defined situations. If a network provider was genuinely unavailable within a reasonable distance, many plans have a process for network adequacy exceptions.
11. Pre-existing condition
The insurer says the condition existed before coverage began. In individual and group major medical coverage, ACA rules sharply restrict this. It remains common in other products — short-term plans, some disability and pet policies, and travel coverage.
What fits: the definition in your specific policy, and the lookback period. These vary enormously between products.
12. Valuation, not coverage
The claim was accepted, but the amount offered is far below the cost of repair or replacement. Technically not a denial at all, though it can feel like one.
What fits: this is what the appraisal clause exists for. Most property and auto policies contain one: each side appoints an appraiser, the two select an umpire, and the resulting decision is typically binding on the amount. Independent estimates are the evidence. Also check whether the settlement was calculated on actual cash value when your policy provides replacement cost, and whether recoverable depreciation is being withheld pending completion of repairs — which is normal, but you have to know to claim it.
The single most useful distinction: is the insurer making a factual claim or a legal one? Factual claims — this was gradual, this was late, this was not necessary — are answered with documentation. Legal claims — this provision excludes it — are answered with policy language and often with professional help. Reading the denial letter closely is what tells you which one you have.
What none of this guarantees
Some denials in every one of these categories are correct. A flood really is excluded from a standard homeowners policy. A roof at the end of its service life really has worn out. A policy that lapsed for non-payment really was not in force.
Knowing the category does not tell you that you will win. It tells you what the argument is about, which is the necessary first step before deciding whether to have it.
Where to verify this yourself
- Your policy — exclusions, carve-backs, conditions, and the appraisal clause.
- Your state Department of Insurance — state rules on late notice prejudice, cancellation notice requirements, and misrepresentation standards.
- CMS — No Surprises Act protections and health plan appeal rights.
- NAIC — model claim handling standards and the state regulator directory.
This is general education, not advice. Insurance law and claim rules vary by state and change over time. Nothing here is legal, financial, or insurance advice for your situation, and reading it does not create any professional relationship. For your specific case, consult a licensed professional in your state or contact your state Department of Insurance.