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.
Sorting the twelve by what actually helps
Grouping them by cause is how the letter presents them. Grouping them by what answers them is more useful, because it tells you where to spend your time.
| Group | Denials | What answers it |
|---|---|---|
| Factual disputes | Wear and tear · Late notice · Failure to mitigate · Not medically necessary | Documents, expert assessment, dated photographs, records |
| Documentary disputes | Policy not in force · No proof of loss · Prior authorization | Payment records, delivery receipts, notice copies |
| Legal disputes | Exclusion · Anti-concurrent causation · Misrepresentation · Pre-existing condition | Policy language, state law, usually professional advice |
| Valuation disputes | Amount too low | Independent estimates, and often the appraisal clause |
The distinction matters because effort spent in the wrong column is wasted. Gathering photographs against a legal argument about what a provision means changes nothing, and arguing interpretation when the real dispute is what a report shows changes nothing either.
The evidence each factual denial actually needs
Wear and tear
- The failed component itself, bagged and labelled with date and location
- Close photographs of the failure surface with something for scale
- A written assessment from a licensed professional describing the failure mode
- Maintenance and service records for the system
- Evidence of when the area was last seen dry — a photograph, a delivery, a visit
Late notice
- When the damage was actually discovered, and how
- Why it was not discoverable earlier — concealed location, seasonal use, absence
- Every attempt to report, including calls that went unanswered
- Evidence that the delay did not impair the investigation, since many states require prejudice to be shown
Failure to mitigate
- Receipts for tarps, boarding, extraction, emergency plumbing
- Photographs of the mitigation in place, dated
- Times and dates of each action taken
- Any invoice from an emergency service describing the scope
A closer look at three that are commonly misunderstood
Late notice is not automatically fatal
Policies require prompt notice, and insurers deny on it. What many people do not know is that a large number of states require the insurer to show the delay actually prejudiced its ability to investigate before late notice can defeat a claim.
The practical consequence: if the damage is still there to inspect, the contractor's report still exists, and the cause is still determinable, the argument that the insurer was harmed by the delay is considerably weaker. Whether your state applies that rule, and how, is a question for your Department of Insurance or an attorney licensed there.
Proof of loss deadlines can be waived by conduct
A missed proof of loss deadline reads as final. In many states it is not, where the insurer continued handling the claim without objecting — requesting documents, arranging inspections, discussing settlement.
The reasoning is that an insurer cannot treat a condition as satisfied for months and then rely on its breach. This is state-specific and it is the kind of argument that benefits from advice, but it is worth knowing the door is not always closed.
Valuation denials are not denials at all
Read the operative sentence precisely. "The claim is denied in its entirety" and "no additional payment will be issued beyond the amount already tendered" are different outcomes.
The second means coverage was accepted and the disagreement is about amount — which opens the appraisal clause, a tool that does not exist for coverage disputes. People who read the second as the first spend months on the wrong argument.
Health denials: the codes on the letter
Health plan denials arrive with reason codes, and the code tells you which of two very different situations you are in.
Administrative denials
- Prior authorization not obtained
- Out of network provider
- Coding or billing error
- Coverage not active on service date
- Often resolved by the provider's billing office
Clinical denials
- Not medically necessary
- Experimental or investigational
- Step therapy not completed
- Exceeds benefit limits
- Requires a physician letter engaging the plan's criteria
A surprising proportion of health denials are in the left column and are fixed by a phone call between the provider's billing office and the plan. Before writing an appeal, ask the provider whether the denial is administrative — it can save weeks.
Frequency by category, and why it is not published
People reasonably ask which denial reason is most common. The honest answer is that no single reliable national breakdown exists in a form we would be comfortable citing as a percentage.
What is published: the NAIC produces reports through its consumer information source showing the reasons with the most closed confirmed complaints by number and percentage, broken down by type of insurance. Many state departments publish their own complaint studies as well.
Those measure complaints, which is not the same as denials — people complain when something goes wrong and they know the option exists. But they are real data, they are free, and they are the closest thing available. Looking at the reasons behind complaints in your line of business tells you where disputes cluster.
When two reasons appear in one letter
Insurers sometimes deny on more than one ground. This matters because an appeal has to answer all of them.
A denial citing both late notice and wear and tear will not be reversed by defeating one. If you resolve the notice question and the wear and tear finding stands, the outcome is unchanged.
Read the letter for the word "and". Where multiple grounds appear, address each separately with its own evidence and its own heading, so the reviewer can see that none was left unanswered.
A triage sequence
-
First hour
Identify the category
Which of the twelve, and whether the insurer is making a factual, documentary, legal or valuation claim. This determines everything after it.
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First day
Find the provision in your own policy
Read it in full including carve-backs and ensuing loss language. Note your suit limitation deadline.
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First week
Request the claim file
Especially where an expert report is referenced. You cannot answer reasoning you have not read.
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Weeks one to three
Gather what the category requires
The checklists above. For legal disputes, this is when to consult an attorney rather than gather more photographs.
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Inside the appeal window
File, even if evidence is still coming
State that supplemental material will follow. A timely appeal completed later beats a late one that was perfect.
The denials that are simply correct
Worth a section of its own, because a guide listing twelve ways to be denied can read as an implication that all twelve are unjust.
They are not. 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 on the date of loss. Intentional damage is excluded everywhere, for obvious reasons.
The purpose of understanding the categories is to tell quickly which situation you are in. Recognising a correct denial in week one, rather than month six, is itself a useful outcome — it redirects the effort toward funding the repair.
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.