How to Appeal a Medicare Claim Denial: A Step-by-Step Guide

What triggers a Medicare appeal in the first place

An appeal becomes relevant any time Medicare denies a claim, pays less than expected, or determines a service wasn't medically necessary. This is a genuinely different process from the fast-appeal rights tied to ending skilled nursing or home health services specifically — the five-level process described here applies to denied claims generally, across Part A, Part B, Part D, and Medicare Advantage.

Common denial reasons include a service deemed not medically necessary, a diagnosis code that doesn't clearly support the billed procedure, a provider considered out-of-network for a specific plan, or a claim submitted with incomplete or missing documentation. Reading the specific reason stated on your denial notice — rather than assuming it's simply an error — is the necessary first step, since the appeal strategy that actually works differs depending on which of these categories applies to your specific situation.

Level 1: Redetermination

The first appeal level is a redetermination, handled by the same Medicare Administrative Contractor (MAC) that processed your original claim. You have 120 days from the date you receive your denial notice to file, and there's no minimum dollar amount required at this level. The MAC generally issues a decision within 60 days.

Filing a redetermination request is generally straightforward: it can be submitted in writing using the specific form referenced on your denial notice, or in some cases through your Medicare Administrative Contractor's online provider portal. Include a clear, specific explanation of why you believe the original decision was incorrect, along with any supporting documentation, rather than a general statement of disagreement — a request that engages directly with the stated denial reason tends to fare better than one that simply restates the original claim.

It's worth checking your Medicare Summary Notice or Explanation of Benefits carefully for the specific denial code and reason before drafting anything, since a redetermination request that addresses the wrong issue entirely — arguing about medical necessity when the actual denial was for a missing referral, for instance — wastes the 60-day review window on a response that doesn't engage with what the MAC actually flagged in the first place.

Level 2: Reconsideration

If the MAC upholds its own denial, the second level — reconsideration — is handled by a Qualified Independent Contractor (QIC), a panel including physicians with no relationship to the original MAC. This is the first genuinely independent review of the claim. You have 180 days from the redetermination decision to file, again with no dollar minimum, and the QIC generally decides within 60 days.

This level is worth treating as your best real opportunity to submit strong evidence, since CMS restricts introducing new documentation at the next level. A physician's letter, complete diagnostic results, and citations to relevant clinical guidelines belong here — not held back for a later stage.

It's also worth knowing that if the QIC misses its own 60-day deadline without issuing a decision, you generally have the right to escalate the case directly to the ALJ level without waiting any longer — a genuinely useful procedural protection if a case seems to be sitting without movement well past the stated timeframe. Confirming this option with a knowledgeable advisor before assuming you simply have to keep waiting is worth doing if a deadline has clearly passed.

Level 3: The ALJ hearing — and why 2026 looks different

The third level is a hearing before an Administrative Law Judge (ALJ), administered by the Office of Medicare Hearings and Appeals (OMHA). You must file within 60 days of the QIC's reconsideration decision, using form OMHA-100, and the amount still genuinely in dispute must meet a minimum threshold — $200 for calendar year 2026, up from $190 in 2025. This threshold is calculated after subtracting any amount Medicare already paid and any deductible or coinsurance you owe, so it's the true disputed balance that counts, not the full original claim amount.

Here's the genuinely important update: OMHA's ALJ stage carried a severe historical backlog, with average processing times reaching over 1,400 days at their worst. That has changed substantially — OMHA's own published data for fiscal year 2026 puts average processing time at roughly 69 days, within the 90-day period regulations actually call for. If you'd heard this stage takes years, that's outdated information; it no longer reflects current reality for most appeals.

It's worth understanding what actually happens at this stage beyond just the timeline. Unlike the paper-record reviews at redetermination and reconsideration, the ALJ hearing involves a genuine de novo review — the judge reconsiders medical necessity and documentation questions fresh, rather than simply checking whether the prior reviewer followed proper procedure. Hearings can be conducted by phone, video conference, or in person, and in certain circumstances you can request an on-the-record review by the ALJ or an attorney adjudicator instead of a live hearing, if you'd prefer to skip the hearing itself and rely on the written record alone.

Levels 4 and 5: Appeals Council and federal court

If the ALJ's decision is unfavorable, the Medicare Appeals Council is the fourth level, with a filing deadline of 60 days from the ALJ's decision. If the Appeals Council also rules against you, the fifth and final level is judicial review in federal district court, again within 60 days, but only if at least $1,960 remains in dispute for 2026 — up from $1,900 in 2025. If a single claim doesn't reach that threshold on its own, combining multiple related claims can sometimes meet it.

In practice, very few appeals reach these final two levels — most legitimate disputes resolve at redetermination, reconsideration, or the ALJ hearing, where the combination of independent physician review and a genuine de novo hearing tends to catch and correct most errors. The Appeals Council and federal court levels exist as a genuine backstop for cases where a real, unresolved legal or factual dispute remains, but they involve meaningfully more time, complexity, and often legal representation than the earlier stages.

How to actually build a strong appeal

• Read the denial notice carefully and identify the specific stated reason for denial.
• Gather complete clinical documentation — physician letters, diagnostic results, guideline citations — early, ideally by the reconsideration stage.
• Track every deadline precisely; missing one generally forfeits that level of appeal entirely.
• Confirm your remaining disputed amount before requesting an ALJ hearing or federal court review.
• Keep copies of everything submitted at every level, in case a later stage requires the full record.

It's also worth calendaring deadlines the moment a denial notice arrives, rather than waiting until closer to the filing window. Medical documentation can take real time to gather — requesting records from a specialist's office, or a written letter of medical necessity, doesn't always happen quickly, and starting that process with 100 days remaining rather than 20 gives meaningfully more room for delays that are entirely outside your control.

A note on Medicare Advantage and Marketplace appeals

Medicare Advantage (Part C) claims follow a similar structure, but the process starts with an internal plan-level appeal before an Independent Review Entity (IRE) takes over the reconsideration role — after that, the same ALJ, Appeals Council, and federal court levels apply, with the same $200 threshold for 2026. This is genuinely distinct from the appeals process for an ACA Marketplace plan, which follows its own separate internal-then-external review structure entirely unrelated to Medicare's five levels — confirming which system actually applies to your specific plan is worth doing before assuming the two work identically.

Disclaimer: This guide is general educational information about the Medicare claims appeals process and is not medical, insurance, or legal advice. Deadlines, dollar thresholds, and processing times change annually and can vary by case. Verify current details with Medicare.gov, CMS, or a licensed Apollo Health Insurance agent, and consult a qualified representative or attorney for help with a specific appeal. Apollo Health Insurance is a licensed insurance brokerage; we are not affiliated with the federal government or any state agency.