A medical denial occurs when your health insurance company refuses to pay for a healthcare service, procedure, or medication. It is one of the most common and frustrating experiences in American healthcare, affecting millions of patients every year. Understanding what a medical denial means and how to respond is essential for protecting both your health and your finances.
The good news is that a medical denial is rarely the final answer. Federal law guarantees your right to appeal, and independent reviews overturn a meaningful share of denials — enough to make the effort worthwhile. This guide explains the causes of medical denials, your legal rights, and the specific steps you should take to challenge an unfair decision. It is general educational information, not legal or insurance advice, so always check your own plan documents for the exact rules and deadlines that apply to you.
What Causes a Medical Denial
Medical denials happen for a variety of reasons, and pinpointing the exact cause is the first step toward overturning one. Your Explanation of Benefits (EOB) or denial letter should state the reason clearly, but the language can sometimes be confusing. Here are the most common categories.
Medical necessity. The insurer determines that the service was not required for your condition or that a less expensive alternative would have been sufficient. These denials often rely on clinical guidelines that the insurer applies broadly, sometimes without adequate consideration of your individual circumstances. A detailed letter of medical necessity from your treating physician is the most powerful tool for overturning them.
Prior authorization. The service required advance approval from the insurer, and either no approval was sought or the request was denied. Prior authorization requirements have expanded dramatically in recent years, covering everything from imaging studies to prescription medications, and CMS has finalized rules aimed at speeding up and adding transparency to prior-authorization decisions for many federally regulated plans.
Coverage limitations. Your plan does not cover the specific service, or you have exceeded a benefit limit such as a maximum number of therapy visits per year. Review your plan’s Summary of Benefits and Coverage carefully to confirm whether the service is truly excluded or simply capped.
Administrative errors. Incorrect billing codes, missing information, out-of-date insurance details, or data-entry mistakes by the provider or insurer caused the claim to be rejected. These are often the easiest denials to resolve — sometimes with a single phone call to correct and resubmit.
Your Rights After a Medical Denial
Federal law under the Affordable Care Act provides strong protections for patients facing medical denials. Every non-grandfathered health plan must offer at least one internal appeal and access to an external review by an Independent Review Organization (IRO). (Note that some plans — such as certain self-funded employer plans governed by ERISA, or short-term plans — follow different rules; the U.S. Department of Labor oversees appeals for most private-sector employer plans.)
Your insurer must send a written denial notice that explains the reason, cites the plan provision, describes any additional material you could submit, and provides instructions for filing an appeal. Under federal rules, insurers must generally notify you of a decision within specific timeframes: for urgent (pre-service) care, as soon as possible and typically within 72 hours; for other pre-service claims, within about 15 days; and for claims for care you already received (post-service), within about 30 days. Deadlines can vary by plan and situation, so confirm the exact figures in your plan documents.
You also have the right to review your complete claim file, including internal notes and the clinical criteria the insurer used. Request this file promptly after receiving a denial, because it reveals the insurer’s reasoning and helps you build a targeted appeal.
How to Appeal a Medical Denial
The appeal process follows a structured path. Start with an internal appeal by submitting a written request to the insurer within the deadline — generally within 180 days of the denial notice, though you should verify your plan’s specific window. Your appeal letter should address each denial reason specifically and include supporting evidence.
Essential supporting documents include your medical records, a letter of medical necessity from your treating physician, published clinical guidelines that support the service, and any relevant pages from your insurance policy. Organize these as labeled exhibits and reference them in your letter. Keep copies of everything you send, and send it in a way you can track. Our appeal letter resources walk through the structure step by step.
The insurer must assign a new reviewer who was not involved in the original denial. If the denial involved a medical judgment, the reviewer must consult a healthcare professional with relevant clinical expertise. The insurer must generally issue a decision within about 30 days for pre-service claims and 60 days for post-service claims.
Expedited Appeals for Urgent Situations
If the medical denial involves a service that is urgently needed to prevent serious harm, you can request an expedited appeal. Insurers must decide an expedited internal appeal quickly — typically within 72 hours. You can usually file by phone, and the insurer cannot require a written submission as a condition of processing the urgent appeal.
You can also request an expedited external review at the same time as the internal appeal if the situation qualifies as urgent. This parallel process can get you a binding independent decision much faster than the standard timeline.
External Review: Your Independent Safety Net
After a final internal appeal denial, you can request an external review. An Independent Review Organization evaluates your case and issues a decision that the insurer must follow. Analyses from state regulators and researchers show that external reviews overturn a significant share of denials — often reported in the range of roughly 40 to 60 percent, though rates vary by state, year, and case type.
To request an external review, contact your state insurance department or follow the instructions in your final internal-appeal denial letter. You generally have about four months (120 days) to file, but confirm your own deadline, because missing it can forfeit the right. The review is conducted by clinical experts in the relevant specialty, and standard reviews typically take around 45 days, with faster timelines for urgent cases.
The Role of CMS and State Regulators
The Centers for Medicare and Medicaid Services (CMS) oversees denial and appeal practices in Medicare, Medicaid, and ACA marketplace plans, and has increased scrutiny of denial rates and prior-authorization practices. CMS also administers the No Surprises Act (see below).
State insurance departments regulate most commercial insurers and can investigate complaints about improper denial practices. Filing a complaint with your state Department of Insurance adds regulatory pressure and creates a record that may help future policyholders. The National Association of Insurance Commissioners (NAIC) maintains a directory of state insurance departments on its website, and many states also run free Consumer Assistance Programs that can help you appeal.
The No Surprises Act and Emergency Care
The No Surprises Act adds important protections. It generally bans surprise bills for emergency services, for out-of-network care delivered at an in-network facility (for example, an out-of-network anesthesiologist at an in-network hospital), and for most air-ambulance services. It also gives uninsured and self-pay patients the right to a “good faith estimate” of expected charges before non-emergency care. If you receive a denial or a surprise bill in one of these situations, cite these federal protections in your appeal — such denials are often reversed quickly once the insurer is reminded of its obligations.
Preventing Medical Denials
While you cannot eliminate the risk entirely, you can take steps to reduce it. Verify coverage before receiving any non-emergency service. Obtain prior authorization when required and get the reference number in writing. Confirm that your provider is in-network and that the facility where the service will be performed is also in-network.
Ask your provider’s office to verify the billing codes before submitting the claim. A single incorrect code can trigger a denial that takes weeks or months to resolve. Building a habit of proactive verification — and keeping your own file of authorizations, EOBs, and notes on every call — can save you significant time and stress.
Frequently Asked Questions
What is the difference between a medical denial and a claim rejection?
A rejection means the claim was not processed at all, usually due to a technical error like an invalid code or missing information. A denial means the claim was processed but the insurer decided not to pay. Rejections are typically resolved by correcting and resubmitting the claim, while denials require a formal appeal.
Can my doctor help me with a medical denial?
Absolutely. Your physician can write a letter of medical necessity, participate in a peer-to-peer review with the insurer’s medical reviewer, and provide updated medical records. Physician involvement significantly strengthens most appeals.
How much does it cost to appeal a medical denial?
Filing an appeal is free. The main cost is your time in gathering documentation and writing the letter. Free help is also available through many state Consumer Assistance Programs and your state Department of Insurance. If you hire an attorney or patient advocate, they may charge a fee, though some work on contingency.
What if I receive a medical denial for emergency care?
Under the ACA and the No Surprises Act, insurers must generally cover emergency services without prior authorization, regardless of whether the provider is in-network. If your emergency care was denied, cite these federal protections in your appeal. Emergency denials are often overturned quickly when the insurer is reminded of its legal obligations.
How long do I have to appeal?
Deadlines vary by plan, but you generally have up to 180 days to file an internal appeal and about four months after a final denial to request external review. Because missing a deadline can end your appeal rights, check the specific dates in your denial letter and plan documents as soon as you receive a denial.
Fight the Denial and Protect Your Health
A medical denial does not have to stand. The appeals process exists specifically to give you a fair chance to present your case and hold your insurer accountable. Start by understanding the denial, gather strong evidence, meet your deadline, and escalate to external review if needed. For detailed guidance, see our articles on how to successfully appeal a denial, explore our appeal letter resources, and visit our healthcare policy guide.
The short version: A medical denial is a starting point, not the end. Read your denial letter and EOB to find the exact reason, then use your ACA internal appeal (generally within 180 days) and, if needed, external review (generally within about 4 months of the final denial). Document everything, get a physician letter of medical necessity, and lean on free help from your state Consumer Assistance Program and Department of Insurance. Emergency care and many surprise bills are protected under the ACA and the No Surprises Act. Check your own plan’s process and deadlines.
This article is general educational information, not legal, medical, or insurance advice. Rights, timelines, and rules vary by plan type and state and change over time; verify the current details with your plan documents, your insurer, and official sources such as HealthCare.gov and CMS before acting.
Sources
- HealthCare.gov — Appealing a health plan decision: internal appeals and external review (healthcare.gov)
- Centers for Medicare & Medicaid Services — oversight of denials and prior authorization (cms.gov)
- CMS — No Surprises Act protections (cms.gov/nosurprises)
- U.S. Department of Labor, Employee Benefits Security Administration — ERISA claims and appeals (dol.gov/agencies/ebsa)
- National Association of Insurance Commissioners — state insurance department directory (naic.org)