How to Appeal an Insurance Denial — Getting Your Heart Care Covered
Written by a practicing, board-certified American cardiac surgeon, grounded in clinical experience and verified primary sources.
Medical Disclaimer: This content is for educational purposes only and is not medical, legal, or financial advice. It explains how insurance denials and appeals generally work and how to take part in the process, not what your specific plan covers or how your own case will be decided. Coverage rules, deadlines, and appeal steps vary by plan type and by state, so always check your own plan documents and denial notice, and consult qualified professionals for decisions about your care, your coverage, and your finances. Never delay seeking care because of a coverage dispute. This guide is meant to help you exercise rights you already have, not to replace your plan, your clinicians, or your own judgment.
In brief: A denied claim is not final. You can appeal it, and appeals often work. In 2024, insurers selling marketplace plans denied about one in five in-network claims, but only about five percent of those denials were for lack of medical necessity; most were administrative or unexplained. Fewer than one percent of denied claims are ever appealed. When people do appeal, they often win: in Medicare Advantage, plans overturned about three-quarters of the denials that were appealed. This article shows how to read a denial, fix what is clerical, get your doctor’s voice into the file, and use your right to an internal appeal and then an independent external review. It also covers how to move fast when care is urgent, and how to protect coverage you already have when your plan changes. None of it requires a lawyer. What it takes is persistence: meeting deadlines, sending documents, and not stopping at the first no.
A denial is a first answer, not the verdict
A denial letter is designed to feel final. It is not. To see why, look at what denials are made of. Insurers selling plans on HealthCare.gov denied about nineteen percent of in-network claims in 2024, close to one in five. But of those denials, only about five percent were for lack of medical necessity. The largest shares were a catch-all “other” category and administrative reasons, with another slice for a missing prior authorization or referral [1]. In plain terms, many denials come from administrative requirements, documentation gaps, or authorization rules rather than a judgment that the care itself is unnecessary.
The second fact is the one the system relies on you not knowing. Almost no one appeals. Fewer than one percent of denied marketplace claims are challenged [1]. Yet appeals succeed often enough to justify the trouble every time. When marketplace enrollees did appeal, insurers reversed roughly a third of denials on internal review alone [1]. The pattern is starker in Medicare Advantage, where a federal investigation found that plans overturned about three-quarters of the denials that were appealed, while only about one percent of denials were ever appealed in the first place [2]. Read that twice. Most denials that get challenged are reversed, and almost none get challenged.
So the single most useful thing to understand about a denial is structural, not medical. It is a first answer in a process that has several more steps, and the steps favor the person who takes them. The system effectively rewards persistence. Most people stop at the first denial, which is exactly why the ones who keep going succeed far more often than they expect.
Why denials happen
It helps to understand what produces these denials, because the picture in most people’s heads is wrong. A denial is rarely a person deciding you do not deserve care. Far more often, a request simply failed to satisfy a rule, a criterion, or a documentation requirement, and a system designed to control cost and standardize decisions returned a no. The mechanics behind that are mundane: limited information in the file, automated workflows, rigid policy rules, utilization-management criteria, and cost control. Understanding this is not about excusing it. It is about staying strategic instead of taking it personally. A denial often feels personal. It usually is not, and reading it as a rule that was not met, rather than a verdict on you, is what lets you answer it with the right fix instead of an argument.
Coverage decisions are not medical decisions
It helps to be precise about what a denial is, because the word carries more weight than it should. A denial means one thing: the insurer has not agreed to pay. It does not mean the treatment is unnecessary, and it does not mean your doctor was wrong to recommend it. Those are medical judgments, made by people who examined you and know your history. A coverage decision is made against a policy, often by someone who has never seen you, matching your file to a rule.
The two can disagree, and when they do, the medical judgment is not erased by the coverage one. Your cardiologist can still hold that the stress test or the medication is the right next step. The plan can still decline to pay for it. The appeal exists to resolve that gap, by putting the clinical reasoning in front of the coverage decision. Keeping the two ideas apart is what keeps a denial from feeling like a verdict on your health. It is a verdict on a payment, and payments can be appealed.
What gets denied most often in heart care
Denials are not random. In cardiovascular care, a familiar set of services draws them, usually because the service is costly, a cheaper option exists that the plan wants tried first, the plan’s criteria are narrower than the clinical guideline, or the documentation did not show the indication clearly enough.
| Commonly denied cardiac service | Why it tends to draw a denial |
| PCSK9 inhibitors and specialty cholesterol drugs | High cost; plan wants cheaper statins or ezetimibe tried and documented first |
| GLP-1 receptor agonists | High cost and tight coverage criteria, often limited by diagnosis or prior drugs |
| Stress testing, cardiac CT, or PET imaging | Plan criteria narrower than the guideline, or the indication not documented clearly |
| Cardiac rehabilitation | Eligibility or referral not documented, even when the patient qualifies (Article 10) |
| Electrophysiology procedures | Cost and strict criteria for the specific rhythm indication |
| Sleep apnea testing | Plan prefers home testing first, or wants symptoms documented |
| Out-of-network specialty consultations | Network rules, or no prior authorization for the out-of-network visit |
The service changes; the appeal does not. Whatever was denied, the strongest appeal ties the requested care to an established clinical guideline and to your own documented history: the drugs you tried before and how you responded, the symptoms on record, the test results that justify the next step. A denied PCSK9 inhibitor and a denied stress test are answered the same way, by showing that the recognized standard supports the care for a patient in your situation. When the denial is a drug you cannot afford while you fight it, Article 4 covers ways to bridge the cost in the meantime.
Prior authorization and a claim denial are not the same thing
Two different events both get called a denial, and telling them apart tells you when to act.
| Prior authorization denial | Claim denial | |
| When it happens | Before the care, the plan refuses to approve it in advance | After the care, the plan refuses to pay the bill |
| What is at stake | Access to the test, drug, or procedure your doctor ordered | The balance you may be billed for care already given |
| The urgency angle | You can ask for speed if the delay itself is dangerous | The appeal runs alongside sorting out the bill (Article 12) |
The appeal logic is the same for both. The timing, and what is at stake while you wait, is different. When a denial arrives, the first question to settle is simply which of the two you are holding.
The first day: what to do when a denial arrives
Before the deeper steps, here is the short version for the day the letter lands. None of it takes long, and doing it early protects every option that follows:
- Save the denial notice, and note the date it arrived.
- Identify whether it is a prior authorization denial or a claim denial.
- Find the exact reason given, including any code.
- Call your clinician’s office and tell them about the denial.
- Ask whether a peer-to-peer review is available.
- Write down every deadline named in the notice.
- Request the insurer’s coverage criteria in writing.
Each of these is expanded below. The reason to do them on day one is simple: the clock starts when the denial is issued, and the early moves are the ones that keep the fast paths open.
Read the denial, and get the reason in writing
Every appeal starts from the stated reason, so pin it down exactly. The denial notice, and your Explanation of Benefits, must say why. If the reason is vague, call the plan and ask them to tell you the specific reason and the code, and write down the date, the name of the person, and what they said. The reason decides the fix, and the fixes are not equal in difficulty.
| Denial reason | What it means | How it is usually fixed |
| Clerical or administrative | A wrong code, missing document, misspelled name, or eligibility flag | Often corrected by the doctor’s office resubmitting, not a formal appeal |
| Missing prior authorization or referral | The required approval was not obtained first | Sometimes cured by getting the authorization after the fact, or documenting why it was not possible |
| Not medically necessary, or experimental | The plan disputes that the care is needed or proven | A real appeal with clinical evidence; your doctor’s involvement matters most here |
| Benefit not covered, or limit reached | The plan’s contract excludes it or a cap was hit | Read against your plan documents; turns on the contract terms |
Knowing which bucket you are in keeps you from writing a heartfelt medical-necessity appeal when the real problem was a transposed digit, and from assuming a denial is final when it was only a form filled out wrong.
Ask which rule they used
Here is a lever most people never reach for. A plan must apply coverage rules, and you can ask to see the specific ones they used against you. Request, in writing, the clinical criteria or medical policy the plan relied on to deny the service, and the name of the guideline behind it.
Why this matters is documented. When federal investigators audited Medicare Advantage denials, they found that thirteen percent of denied prior-authorization requests met Medicare’s own coverage rules and would likely have been approved under traditional Medicare. A common cause was that the plan applied its own clinical criteria, stricter than Medicare’s, to refuse care that the rules allowed [3]. That is a powerful thing to know when you appeal. If the plan denied you using a standard tougher than the recognized one, the gap between the two is your argument. Ask your doctor whether the denial conflicts with the usual clinical guideline for your situation, and have that disagreement named, in writing, in the appeal.
One subtlety matters here. A denial can be entirely correct under the plan’s own rules and still be appealable, because the rules themselves usually allow exceptions. The plan may have applied its policy perfectly and still owe you a path: a formulary or step-therapy exception, a medical-necessity override, a coverage decision revisited with new documentation. Following a rule and reaching the right answer for your case are not always the same thing, and the exception process exists for exactly that gap.
Get your doctor’s voice into the file
You are not the strongest witness in your own appeal. Your clinician is. The reviewer sees a file. Your physician sees a patient. The appeal exists to connect the two. The person deciding your case almost never meets you; they have only a file of codes, dates, a few notes, and the boxes that were or were not checked. The treating physician is the one who knows the clinical context the file leaves out, the reason a guideline applies to you in particular, the detail that turns a borderline-looking request into an obvious one. A letter or a call from that physician can change the outcome because it supplies the part of the story the record never carried. Two tools put that voice on record, and you can ask for both.
A peer-to-peer review is a direct conversation between your treating doctor and a doctor at the insurance company. In many cases it is the single most useful step in the whole process. A denial that would take weeks to overturn through a formal written appeal can sometimes be reversed in one physician-to-physician call, once the reviewing doctor hears the clinical detail that was missing from the original file. Your physician’s office can request it, often by phone, and it is frequently the fastest way to reverse a medical-necessity denial before it hardens. Ask whether they will, and help by handing them the denial letter and the deadline.
A letter of medical necessity is a written statement from your clinician explaining why this specific care is needed for you, tied to your record and to the relevant guideline. You cannot write it, but you can make it easy to produce: give your doctor’s office the denial reason, the plan’s criteria if you obtained them, and the date the appeal is due. A specific letter that speaks to the plan’s own stated reason does far more than a general one.
Two cautions go with leaning on your doctor’s office. First, you may be the only person who holds the whole administrative story: the timeline, the drugs that failed before, the earlier denials, who promised what and when. The cardiologist knows cardiology and the insurer knows the policy, but that history often lives only with you, so keep it written down and hand it over. Second, never assume an appeal exists until someone confirms it was filed. Offices are busy, and a peer-to-peer you requested or records you expected to be sent may not have happened. A short call to confirm the appeal is in, with a reference number, protects you from a deadline passing on a step everyone assumed was done.
What a strong appeal contains
You do not need legal language, and a longer letter is not a better one. A clear appeal does a few things in order. It identifies the claim and the exact denial reason you are rebutting, so the reviewer knows what is in dispute. It states plainly what you are asking the plan to do. It attaches the clinical evidence: your doctor’s letter of medical necessity, the relevant records, and the recognized guideline that supports the care, set against the plan’s own stated criteria. And it includes a short statement, in your own words, about what the care is for and what is at stake. Keep a copy of everything you send, use a method you can track, and write the date sent next to the deadline. A focused packet that answers the plan’s specific reason does more than a long one that talks around it.
The deeper point is that appeals are won more often by documentation than by persuasion. You are usually not trying to change a mind; you are supplying what the file was missing. Most successful appeals turn on the same few gaps:
- information that was simply missing the first time
- criteria that were met but not documented
- prior treatment failures that were not included
- clinical context the original reviewer never had
Each of those is a document or a fact, not an argument, which is good news: it means the appeal is something you and your doctor’s office can assemble, not a debate you have to win.
Know your rights, and the deadlines
For most private plans, the appeal path is set by law, and it has two stages. The first is an internal appeal, where you ask the insurer to reconsider. The second is an external review, where an independent third party that does not work for your insurer takes a fresh look, and by law the insurer must generally follow that decision; if the reviewer overturns the denial, the plan must cover the care [4,5].
| Stage | The deadline |
| Filing an internal appeal | Up to 180 days, about 6 months, from the denial notice |
| Plan’s decision, care not yet received | About 30 days |
| Plan’s decision, care already given | About 60 days |
| Plan’s decision, urgent situation | As little as 72 hours |
| Requesting external review | Generally after the final internal denial |
| External review decision | About 45 days standard, or 72 hours if urgent [4] |
Treat these dates as the hardest part of the process. A strong appeal filed late can fail on the calendar alone. Missing a deadline is one of the few mistakes that permanently ends an otherwise winnable appeal, so when you file matters as much as what you file. The external review is one of the strongest consumer protections in American health care: the federal process is free, and where a state or independent organization runs it, the charge cannot exceed twenty-five dollars [4].
Two cautions keep this accurate. First, the exact process depends on your plan type. Marketplace and most employer plans follow the rules above, but Medicare and Medicaid run their own multi-level appeals, and some employer plans differ in the details. Your denial notice is required to tell you how to appeal and by when, so read it for your specific path. Second, you do not have to do this alone: your state’s Consumer Assistance Program or Department of Insurance can help you file, and a hospital financial counselor or your clinic’s billing staff often will too.
If it is urgent, say so
Speed is its own tool, and you have to ask for it. If waiting for the standard timeline could seriously jeopardize your health or your ability to recover function, you can request an expedited appeal, decided within seventy-two hours. In urgent cases you can also ask for the internal appeal and the external review to run at the same time, rather than one after the other [4,5]. Your doctor can certify the urgency in writing. When care cannot safely wait, do not let a slow standard clock run in the background; say plainly that the situation is urgent and ask for the fast track.
The strongest appeal is built before the denial
Here is the part that sounds backward and holds true: the best time to win an appeal is before the denial happens. Most of what makes an appeal succeed is not argument. It is the record that already exists when the request is first submitted, and that record is built in the exam room, not the appeals department.
A few things do most of the work. Accurate documentation, where the note states the diagnosis, the symptoms, and the reasoning in plain clinical terms. A guideline-supported indication, where the request matches an established recommendation rather than stretching one. Complete records, so the drugs you tried before, the tests you have had, and how you responded are all in the file rather than in someone’s memory. And prior authorization handled with care, where the request goes in with the supporting evidence attached the first time, instead of as a bare order that invites a reflexive no.
None of this is yours to write, but some of it is yours to prompt. You can make sure your clinician’s office has your full history, including care from other doctors. You can ask, before a costly test or medication, whether prior authorization is needed and whether the supporting documentation is ready. You can keep your own copies. A request that arrives complete and guideline-backed is the one least likely to be denied, and the easiest to defend if it is. The appeal you never have to file is the one that was prepared properly from the start.
Protecting coverage you already have
Some of the hardest denials are not for new care but for care you were already getting, after something about your plan changed. Coverage can shift at renewal or when you switch plans, and there is a specific remedy for each, which you should request by name.
| If your plan changes this way | The remedy to request, by name |
| A drug drops off the formulary or moves to a costlier tier | A formulary exception or tiering exception |
| A new “try the cheaper drug first” rule appears | A step-therapy exception, especially if you already failed that drug |
| Your doctor falls out of network, or the plan changes | Continuity-of-care or transition coverage for a defined period |
The time to catch these is at open enrollment. Read the plan’s drug list and summary of benefits before you commit. If a medication you cannot do without is missing, treat that as a reason to choose a different plan, or to file an exception early, rather than discovering the gap at the pharmacy counter.
Persistence is the strategy
Appeals are won by persistence, not brilliance. Almost no one needs a perfect letter; what wins is meeting deadlines, supplying documents, escalating when you have to, and not quitting. So start one folder, physical or digital, and let everything go in it: the denial notice, your Explanations of Benefits, and every letter you send and receive. Add dated notes of each call with the name of the person and a reference number, and any fax or upload confirmations. It sounds mundane, and mundane is what wins, because the folder is what meets the deadline and answers the plan when it claims it never received something. Meet every deadline, because a missed window can end the appeal regardless of merit. Fix clerical errors by resubmission right away, and save the formal appeal for genuine disagreements, escalating from internal to external if you have to. And lean on the help that exists: your clinician’s office, a hospital financial counselor or case manager, and your state’s Consumer Assistance Program or Department of Insurance.
None of this is glamorous, and that is the point. The process rewards the person who keeps a folder and meets the dates. The system is built to make giving up the easy path. The evidence says the people who do not give up are reversed far more often than anyone expects.
The bottom line
A denial is a first answer, not the last word. Few denials turn on medical necessity, many come down to administrative and authorization rules, nearly all go unchallenged, and a large share of the ones that are challenged get overturned. So read the reason and pin it down, fix what is clerical, ask which rule they used, get your doctor’s voice into the file, meet every deadline, and escalate through internal appeal to independent review. When it is urgent, say so and ask for speed.
Insurance companies make coverage decisions. They do not get to decide whether your appeal deserves to be heard. A denial closes one step and opens the next. The patients who understand that difference are most often the ones who, in the end, get the care they need.
Key Terms
Prior authorization: the plan’s approval, required before certain care, for it to be covered; a denial here happens before the service.
Claim denial (adverse benefit determination): the plan’s refusal to pay for care already provided; an appeal runs alongside sorting out the bill.
Explanation of Benefits (EOB): the statement showing what the plan paid or denied and why; not a bill, but the document that names the denial reason.
Internal appeal: asking your insurer to reconsider its own denial; generally filed within one hundred eighty days of the notice.
External review: an independent third party’s review after the internal appeal fails; its decision is binding on the insurer by law.
Peer-to-peer review: a direct conversation between your treating doctor and the insurer’s reviewing doctor, often the fastest way to reverse a medical-necessity denial.
Letter of medical necessity: your clinician’s written explanation of why specific care is needed for you, tied to your record and the relevant guideline.
Formulary or step-therapy exception: a request to cover a drug the plan would otherwise restrict, or to skip a required cheaper-drug-first rule, when it is the right treatment for you.
Expedited appeal: a fast-tracked review, decided within seventy-two hours, for situations where waiting could seriously harm you.
References
- KFF. Claims Denials and Appeals in ACA Marketplace Plans in 2024. Published March 2026. https://www.kff.org/patient-consumer-protections/claims-denials-and-appeals-in-aca-marketplace-plans-in-2024/
- US Department of Health and Human Services, Office of Inspector General. Medicare Advantage Appeal Outcomes and Audit Findings Raise Concerns About Service and Payment Denials. Report OEI-09-16-00410; September 2018. https://oig.hhs.gov/oei/reports/oei-09-16-00410.asp
- US Department of Health and Human Services, Office of Inspector General. Some Medicare Advantage Organization Denials of Prior Authorization Requests Raise Concerns About Beneficiary Access to Medically Necessary Care. Report OEI-09-18-00260; April 2022. https://oig.hhs.gov/reports/all/2022/some-medicare-advantage-organization-denials-of-prior-authorization-requests-raise-concerns-about-beneficiary-access-to-medically-necessary-care/
- US Centers for Medicare and Medicaid Services / HealthCare.gov. Appealing Health Plan Decisions: Internal Appeals and External Review. Accessed June 2026. https://www.healthcare.gov/appeal-insurance-company-decision/
- Internal Claims and Appeals and External Review Processes. 45 CFR 147.136. https://www.ecfr.gov/current/title-45/section-147.136
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