You receive an explanation of benefits in the mail and notice that Medicare denied your claim. Maybe it was for a procedure you already had. Maybe it was for a medication your doctor prescribed. Whatever the service, the denial feels final. It is not. Medicare has a formal appeals process, and a significant number of denials get reversed when beneficiaries follow through correctly.
The Office of Medicare Hearings and Appeals reports that a large share of appealed denials result in full or partial approval for the beneficiary. Most people never appeal at all, which means they leave money on the table that they were legally entitled to. Knowing how the process works gives you a real advantage.
Why Medicare Denies Claims
Before appealing, it helps to understand why the denial happened. Medicare denies claims for several reasons, and the reason shapes your appeal strategy.
The most common reason is a determination that the service was not medically necessary. Medicare uses specific coverage criteria to evaluate whether a treatment is appropriate for a given condition. If your doctor ordered something that falls outside those criteria, even with good clinical reason, Medicare may reject it initially.
Other common denial reasons include billing errors from your provider, services rendered by an out-of-network provider under a plan that restricts network use, duplicate claim submissions, and missing documentation. Sometimes the denial has nothing to do with your clinical situation and everything to do with a paperwork issue on the provider's end. Call your doctor's billing department first and ask whether they submitted the claim correctly before you begin a formal appeal.
The Five Levels of Medicare Appeal
Medicare's appeals process has five levels, and you move through them in order if earlier decisions do not go your way.
The first level is a redetermination, handled by your Medicare Administrative Contractor. You must file this within 120 days of receiving your Medicare Summary Notice. This is the fastest step and the easiest to complete. Submit a written request explaining why you believe the denial was incorrect and include any supporting documents your doctor provides.
The second level is a reconsideration by a Qualified Independent Contractor, which is an outside organization with no connection to the contractor that issued the first denial. File within 180 days of the redetermination decision. At this stage, having a letter from your physician that directly addresses Medicare's medical necessity criteria is one of the most effective things you can submit.
The third level involves a hearing before an Office of Medicare Hearings and Appeals administrative law judge. This level is available when the amount in dispute meets a minimum threshold, which adjusts annually. A judge reviews your case independently, and you have the right to appear in person, by phone, or by video.
The fourth level is a review by the Medicare Appeals Council, and the fifth level is a federal district court review. Most appeals that are going to succeed do so at levels one through three. But knowing the full ladder exists matters if your denial involves a large dollar amount.
What to Include in Your Appeal
The strength of your appeal depends almost entirely on the documentation you submit. A denial letter alone is not enough to reverse a decision. You need to build a case.
Start with a letter from your treating physician that explains why the service was medically necessary in terms that directly address Medicare's coverage criteria. Generic statements like "the patient needed this procedure" are less effective than letters that reference specific Medicare Local Coverage Determinations or National Coverage Determinations by name.
Include your medical records that document the condition being treated, any prior treatments that were attempted, and the clinical reasoning behind the denied service. If the denial was for a prescription drug, your doctor should submit documentation showing that other formulary alternatives were tried and failed, or that they are contraindicated for your condition.
Peer-reviewed clinical literature supporting the treatment is worth adding when the denial is based on a medical necessity determination. Administrative law judges at the third appeal level are permitted to weigh that evidence, and it often makes a difference.
Deadlines You Cannot Afford to Miss
Every level of the appeals process has a filing deadline, and missing one forfeits your right to continue at that level. Write down every deadline the moment you receive a denial or a decision letter. The Centers for Medicare and Medicaid Services publishes clear timelines for each appeal level on its website.
If you need help navigating the process, your State Health Insurance Assistance Program, known as SHIP, offers free one-on-one counseling for Medicare beneficiaries. These are trained volunteers who understand the appeals system and can help you prepare your submission without charging you anything. Find your local SHIP program through the eldercare.acl.gov locator.
Understanding how Medicare's enrollment rules and coverage decisions connect also helps when building an appeal. Gaps in enrollment history or plan selection can affect what Medicare considers covered in the first place, which is why knowing your Medicare enrollment periods thoroughly matters beyond just avoiding late penalties.
A Medicare denial is not a final answer. It is the beginning of a process that exists precisely because denials are sometimes wrong. File the appeal, submit strong documentation, and follow the deadlines. That combination wins more cases than most people expect.