Your Insurance Sent a Denial Letter. Here Is What It Actually Says.

A denial letter is a legal document written to comply with regulatory requirements, not to be understood. The language is dense, the denial reason is compressed into a phrase that obscures more than it reveals, and the information you most need — the appeal deadline — is frequently buried in the final pages.

This is not an accident. It is the result of decades of regulatory layering, insurance industry drafting conventions, and medical review processes designed by compliance departments rather than by people who need to read them under stress.

Here is what the letter actually contains, and what to do with it.

What the Law Requires

Under the Affordable Care Act and ERISA regulations governing employer-sponsored health plans, every denial letter must include four specific pieces of information.

The first is the specific reason for denial, stated in language that a layperson can understand. This requirement exists, though interpretation of what "clear" means has historically favored insurers.

The second is the clinical criteria or plan provisions used to make the decision. If your insurer relied on coverage guidelines from a vendor such as InterQual or MCG Health, the denial letter is required to identify those criteria. You are entitled to request the full text of those guidelines.

The third is information about how to appeal, including which process to use and where to submit your appeal.

The fourth is your appeal deadline.

If your letter is missing any of these four elements, that omission may itself be grounds for a complaint to your state insurance commissioner or, if you are on an employer-sponsored plan, to the U.S. Department of Labor's Employee Benefits Security Administration.

The Six Most Common Denial Reasons

"Not Medically Necessary"

This is the most common denial reason, and the most consequential. It means the insurer's medical director or a contracted physician reviewer concluded that the clinical documentation submitted did not meet the plan's coverage criteria for medical necessity.

Medical necessity determinations are not made by your doctor. They are made by a physician employed by or contracted with your insurance company, reviewing records rather than examining you. That physician may specialize in a different field than your treating provider.

A "not medically necessary" denial is appealable and frequently overturned when additional clinical documentation is provided. Your physician can also request a peer-to-peer review, which is a direct conversation between your doctor and the insurer's reviewing physician, before or during the appeals process. Many prior authorization denials are reversed at this stage before a formal appeal is ever filed.

"Experimental/Investigational"

This denial reason means the insurer determined that the drug or treatment does not meet its evidence standards for established clinical benefit. This determination can be wrong.

FDA approval does not automatically satisfy an insurer's experimental/investigational criteria. Conversely, some FDA-approved drugs are still classified as experimental by specific plans for specific indications. A 2019 study published in JAMA Internal Medicine found that insurer coverage policies frequently lag behind FDA approvals by years, meaning covered indications in insurer guidelines may be narrower than what the FDA has approved.¹

If you received this denial for an FDA-approved drug prescribed for an FDA-approved indication, document both the drug's approval date and its approved indication in your appeal. The FDA's prescribing information, available through the FDA's Drugs@FDA database, is an authoritative source.

"Prior Authorization Required/Not Obtained"

This is an administrative denial, not a clinical one. It means the drug was dispensed or administered before the insurance company approved it, or the prior authorization was never submitted. In many cases this is correctable, either through a retroactive prior authorization request or by confirming that your provider submitted the PA and the insurer did not receive it.

Contact your provider's office before doing anything else. Ask whether a prior authorization was submitted, when it was submitted, and whether they have a reference or fax confirmation number. Missing PAs are often a systems failure on the administrative side, and locating the confirmation can resolve the denial without a formal appeal.

"Step Therapy Requirements Not Met"

Your plan requires you to try and demonstrate failure on a less expensive drug before it will approve the prescribed medication. This is called a fail-first or step therapy protocol.

Many states have enacted step therapy exception laws requiring insurers to grant an exception when a physician documents specific clinical reasons why the step drug is contraindicated, previously failed, or otherwise inappropriate for you. The Global Healthy Living Foundation maintains a current state-by-state step therapy exception legislation map.

Your physician's letter supporting a step therapy exception should document the clinical rationale with specificity. A letter that simply states the prescribed drug is preferable carries less weight than one that identifies the contraindication, prior trial and failure, or clinical risk.

"Quantity Limit Exceeded"

Your prescription exceeds the dosing threshold the plan has approved for that drug. This occurs with weight-based dosing for biologics, or when a physician has prescribed above the plan's standard dose for a documented clinical reason.

A quantity limit denial is typically addressed by having your physician document the medical rationale for the prescribed quantity. For weight-based drugs, that documentation should include current weight and the dosing calculation used.

"Not a Covered Benefit"

This denial means the plan says it does not cover this drug or service at all. Before accepting it, read your Summary of Benefits and Coverage — the standardized document your insurer is required to provide. If the drug appears as a covered benefit in that document, the denial may be factually inaccurate and worth challenging on those grounds alone.

If the drug is genuinely not listed, check whether your plan has a formulary exception process for non-covered drugs. Most plans that comply with the ACA are required to maintain one.

What to Do in the Next 48 Hours

Note the denial date. This is the clock start for your appeal deadline. Internal appeals under ACA-compliant plans must typically be filed within 180 days of a denial, though your plan may specify a shorter window. Read the deadline language carefully.

Request your clinical review file. Under ACA regulations, you are entitled to receive the clinical criteria used in your review and the specific documentation the reviewer considered. Submit this request in writing to your insurer's appeals department. Having this file before you draft your appeal tells you exactly what the reviewer saw and what they found insufficient.

Contact your physician's office. A denial appeal without your physician's participation is structurally weaker than one with it. Let them know a denial arrived so they can decide whether to initiate a peer-to-peer review or prepare a supporting letter before your appeal deadline.

Ellen can decode your specific denial letter and walk you through your next step at ellenrx.com.

The Deadline on Your Letter Is Not Approximate

Insurance denial appeals operate on firm deadlines. If you miss the internal appeal deadline, you may lose the right to internal review entirely, which closes off a significant portion of your appeal pathway. If you are approaching that deadline and do not yet have your clinical file or your physician's letter, file a placeholder appeal that preserves your right to appeal and supplements it with documentation afterward.

The process is designed to be navigated. It just requires knowing where the doors are.

¹ Dusetzina SB, Winn AN, Abel GA, Huskamp HA, Keating NL. "Coverage for Oral Anticancer Drugs in Private Insurance Plans." JAMA Internal Medicine. 2019;179(6):849-851.