A denied claim is upsetting, but it is rarely a final answer — and it is usually about process, not about you. Health plans deny claims for a fairly small set of common reasons: an approval that was not obtained first, a paperwork error, a question about what the plan covers, or too little information in the file. Understanding which reason is sitting in your letter is the first step, because each one has a different fix — and many denials are resolved once the right information reaches the right desk. Your own plan’s letters and documents are the authority on your case; this article explains the landscape in general terms.
Key Takeaways
- A denial is a decision about a claim as it was submitted — it is not a judgement about whether you deserved the care.
- The reason is stated in the denial letter or explanation of benefits, in the plan’s own wording; read that first, before anything else.
- The most common reasons are process problems: missing prior authorisation, missing information, billing errors, or coverage and network questions.
- Each reason has a different next step — correcting paperwork is not the same as appealing a medical decision — so sorting the reason comes first.
- Deadlines for responding exist and they come from your own plan’s documents, not from general articles; work to the dates in your letters.
- Hospital financial counselors help patients work through denials as part of their job — you do not have to untangle it alone.
First, Read the Letter for Its Reason
Denials arrive in two main documents: a denial letter from the plan, and the explanation of benefits (EOB) that accounts for each claim. Both state a reason — sometimes in plain language, sometimes in the plan’s codes and phrases, with a fuller explanation in the letter. Our guide to reading an insurance denial letter walks through one section by section, and our pillar guide to paying for breast cancer care maps the wider system of claims, bills, and appeals that the letter belongs to.
Two things in the letter matter most at the start. The first is the stated reason — the plan’s own explanation of what was wrong with the claim as submitted. The second is what the letter says you can do about it: the steps it describes and the dates it gives. Everything in this article hangs off those two things, because the fix for a missing form is paperwork, while the fix for a medical disagreement is an appeal — and sending one where the other is needed only costs you time.
The Common Reasons, One by One
The plan says approval was needed first
Many services require prior authorisation — the plan’s agreement, obtained before the service, that it fits the plan’s criteria. If that step was missed, done for a slightly different service, or attached to the wrong dates, the claim can be denied even though the care itself was entirely appropriate. This is one of the most common denial reasons of all, and it is often a fixable sequencing problem between the provider’s office and the plan.
The plan says information was missing
Sometimes the file simply did not tell the plan enough: records not attached, a letter of explanation not included, results the reviewer needed not yet received. The denial in these cases is really a request wearing firmer clothing — the plan is saying it cannot say yes on what it has. Your clinician’s office can usually supply what is missing, and a clinician-to-clinician conversation called a peer-to-peer review is sometimes the route by which the missing clinical picture gets across.
The plan says the service is not covered
Every plan has terms — services it covers, services it excludes, and conditions attached to each. A denial on these grounds means the plan is reading its own contract and finding the service outside it, or outside the conditions. These denials turn on the plan’s exact wording, which is in your policy documents, and a hospital financial counselor can help you check the service against them.
The care was out of network
Plans pay differently — sometimes not at all — for care from providers outside their network, and a claim can be denied or reduced when the facility, the doctor, or even one member of a treating team is out of network. Our explainer on in-network and out-of-network care describes how these arrangements work and why they matter at claim time.
There was a billing or paperwork error
Claims are data: codes, dates, names, and numbers, and any of them can be wrong. A service coded incorrectly, a date that does not match the visit, a duplicate claim submitted twice, or a claim sent to the wrong insurer can all produce a denial that has nothing to do with the care itself. Our article on medical bill errors and our guide to reading your explanation of benefits help you spot where the paperwork went astray.
The plan questions medical necessity as documented
Some denials say, in the plan’s phrasing, that the service was not shown to be medically necessary. That is usually a judgement about the documentation rather than the care: the plan’s reviewer did not see, in the file, the reasons your team had. This is the kind of denial that most often leads to a formal appeal, in which your clinician sets out the clinical reasoning in full — a process our guide to appealing a health insurance denial explains end to end.
There is an eligibility or coordination question
Sometimes the denial is about the coverage itself rather than the claim: the plan’s records show coverage inactive on the date of service, or another insurer is recorded as responsible first — common when a household has two plans. These are record-keeping questions, resolved by establishing what coverage was actually in force and which plan is primary.
Sorting Your Denial: A Quick Guide
| What the letter points to | What it usually means | The usual first step |
|---|---|---|
| No prior authorisation on file | The approval step was missed, mismatched, or expired | Ask your provider’s office to review the authorisation and contact the plan |
| Insufficient information | The reviewer could not see enough clinical detail | Ask your clinician’s office what was requested and what will be sent |
| Not a covered service | The plan reads the service as outside its terms | Check the service against your policy documents, with a financial counselor’s help if needed |
| Out-of-network provider | Someone involved in the care is outside the plan’s network | Ask the plan and the provider who was out of network and what options the letter describes |
| Coding or billing error | The claim’s data did not match the care given | Ask the provider’s billing office to review and correct the claim |
| Not medically necessary | The file did not persuade the plan’s reviewer | Talk to your clinician’s office about a peer-to-peer review or a formal appeal |
| Coverage or coordination question | The plan’s records about your coverage need correcting | Call the plan to establish what coverage was in force on the date of service |
The table is a sorting tool, not a diagnosis of your claim — the letter itself always outranks a general guide, and the plan’s stated next steps are the ones to follow.
What to Do Next
- Keep everything. The denial letter, the EOB, the original bill, and notes of every call — date, name, what was said. Paper trails win these processes.
- Find the response date in your letter and work to it. Rules and timeframes vary by plan and by state; the dates that govern your case are the ones your plan gives you.
- Make one call to the plan and one to the provider’s billing office. Ask each to state, in plain language, what was wrong with the claim and what would put it right. Write down the answers.
- Ask your clinician’s office what they will send or say. For information and medical-necessity denials, their documentation is usually the heart of the matter.
- If the fix is an appeal, follow the plan’s process in order. Our walkthrough of filing an internal appeal describes the usual shape of it, and if an internal appeal does not succeed, external review by an independent reviewer may be available — your letters will say.
- Ask a hospital financial counselor for help early. Sorting denials is literally their job, and their guidance costs you nothing to ask for. General consumer information about coverage and appeals is also published at healthcare.gov.
Questions to Ask
- (Your plan) In plain language, exactly why was this claim denied — and what would make it payable?
- (Your plan) Is this a paperwork problem, an information problem, or a decision about the care itself?
- (Your plan) What is the deadline in my case for responding, and what form should the response take?
- (The provider’s billing office) Was prior authorisation obtained for this service — and do the codes and dates on the claim match the care I received?
- (Your clinician’s office) Will you send additional records, or request a peer-to-peer review, in my case?
- (Either) While this is being resolved, what happens to the bill — should I do anything about it in the meantime?
Frequently Asked Questions
Does a denial mean I now owe the full amount?
Not necessarily. A denial is the plan’s first decision on the claim as submitted; many are corrected, reconsidered, or overturned through the steps above, and until the process finishes, the bill’s final shape is not settled. Ask the provider’s billing office what the position is while the claim is being reviewed, and keep every letter you receive.
Should I pay the bill while the denial is being sorted out?
Arrangements vary, so ask rather than guess: many billing offices will note an account as under review while a claim or appeal is in process. What matters is that the conversation happens and is recorded — who you spoke to, when, and what was agreed — rather than the bill sitting unaddressed.
The reason in my letter does not match what actually happened. What then?
That happens more often than you would expect, and it is a good reason to call: if the plan’s records show a different date, service, or authorisation status from the care you received, say so specifically and ask what evidence would correct the record. Billing offices and plans correct their data routinely when the discrepancy is pointed out.
Can my doctor’s office really change the outcome?
Often, yes — particularly for information and medical-necessity denials, where the missing piece is the clinical reasoning only your treating team can supply, through records, a letter, or a peer-to-peer conversation. It is always worth asking the office what they can send before assuming the decision is final.
What if the appeal is denied too?
Further steps may exist: many plans offer more than one level of internal appeal, and an external review by an independent reviewer outside the plan is available in many situations. Your decision letters describe which options apply to you and the dates that govern them. A hospital financial counselor or your state insurance department can also explain the landscape in general terms.
Related Articles
- Paying for Breast Cancer Care: A Complete Guide
- How to Read an Insurance Denial Letter
- Appealing a Health Insurance Denial for Breast Cancer Care
- Filing an Internal Appeal With Your Health Insurer: A Step-by-Step Walkthrough
- External Review: When an Independent Reviewer Looks at Your Appeal
- How Health Insurance Claims Work, Step by Step
This article is for general educational purposes only and is not medical, legal, or financial advice. It does not replace professional care. Talk to your doctor or care team about your own situation. If you think you may have a medical emergency, call 911.