How to Appeal a Medicare Denial — Step-by-Step Guide

Medicare covers more than 65 million Americans, and like any insurance program, it denies claims. In fact, Medicare denies roughly 17% of claims — but what most beneficiaries don't realize is that Medicare's appeal process is one of the most structured and fair in the entire insurance industry. Medicare appeals have five distinct levels, and the success rate at the first level alone is significant.

This guide walks you through the complete Medicare appeals process, covering both Original Medicare (Parts A and B) and Medicare Advantage (Part C), with specific forms, timelines, and strategies for each.

Original Medicare vs. Medicare Advantage: Different Appeal Processes

The appeal process depends on whether you have Original Medicare or a Medicare Advantage plan:

• Original Medicare (Parts A & B): Claims are processed by Medicare Administrative Contractors (MACs). Your appeal goes through the MAC and then through the federal Medicare appeals system.
• Medicare Advantage (Part C): Claims are processed by your private insurance company (like UnitedHealthcare, Humana, or Aetna). Your first appeal goes to the plan, then to an independent reviewer.
• Part D (prescription drugs): Appeals go to your Part D plan first, then to an Independent Review Entity (IRE).

The 5 Levels of Medicare Appeals

Medicare has a unique five-level appeals process. You must generally complete each level before moving to the next:

Important: Level 3 (ALJ Hearing) requires a minimum amount in controversy — approximately $180 for 2026. Level 5 (Federal Court) requires approximately $1,760. These thresholds adjust annually.

Step 1: Understand Your Medicare Denial

For Original Medicare

Denials appear on your Medicare Summary Notice (MSN), which Medicare mails to you every 3 months. The MSN shows:

• Services billed and whether Medicare approved them
• The reason for any denial (using standardized reason codes)
• Your appeal rights and deadlines

You can also check claims online at medicare.gov by logging into your MyMedicare account.

For Medicare Advantage

Your MA plan sends you an Explanation of Benefits (EOB) or denial letter. This includes the denial reason, your appeal rights, and how to file. You can also check your plan's member portal. If you need help understanding it, read our guide to understanding your EOB.

Common Medicare denial reasons

• Not medically necessary — Medicare determines the service doesn't meet medical necessity criteria
• Not a covered Medicare benefit — The service falls outside Medicare's coverage scope
• Frequency limit exceeded — You've received more of a service than Medicare allows in a given period
• Provider not enrolled in Medicare — The provider isn't registered as a Medicare provider
• Observation status vs. inpatient admission — You were classified as "observation" instead of admitted, affecting Part A coverage

Step 2: Level 1 Appeal — Redetermination

For Original Medicare

File your Level 1 appeal (redetermination) with the Medicare Administrative Contractor (MAC) that processed your claim:

1. Use CMS Form 20027 — the Medicare Redetermination Request Form. Download it from cms.gov
2. Or write a letter including your name, Medicare number, the item/service and dates, and why you think the denial is wrong
3. Mail to the MAC listed on your MSN
4. Deadline: 120 days from the date on your MSN
5. Decision timeline: The MAC must decide within 60 days

Include supporting documentation:

• A letter from your doctor explaining medical necessity
• Relevant medical records
• Published clinical guidelines supporting the service
• Any other evidence that the service meets Medicare's coverage criteria

For Medicare Advantage

1. Contact your MA plan using the number on your member ID card
2. File a reconsideration by mail, fax, phone, or through the plan's online portal
3. Deadline: 60 days from the date of the denial notice
4. Decision timeline: 30 days for post-service; 7 days for pre-service; 72 hours for expedited

Fast (expedited) appeal: If your health could be seriously harmed by waiting, request a fast appeal. Your MA plan must decide within 72 hours. Your doctor can request this on your behalf by calling the plan and certifying that a delay could jeopardize your health.

Step 3: Level 2 Appeal — Independent Reconsideration

If Level 1 is denied, you can request an independent review:

For Original Medicare

Your appeal goes to a Qualified Independent Contractor (QIC). The QIC is independent of Medicare and reviews your case fresh.

• Deadline: 180 days from the Level 1 decision
• Decision timeline: 60 days
• Submit any new evidence or documentation

For Medicare Advantage

If your MA plan upholds the denial at Level 1, it must automatically forward your case to an Independent Review Entity (IRE). You don't need to do anything extra — but you can submit additional evidence to the IRE.

• Decision timeline: 30 days for post-service; 72 hours for expedited

Step 4: Level 3 — Administrative Law Judge Hearing

If Level 2 is denied and your claim meets the minimum amount in controversy (approximately $180 for 2026), you can request a hearing before an Administrative Law Judge (ALJ).

• Deadline: 60 days from the Level 2 decision
• File your request through the Office of Medicare Hearings and Appeals (OMHA)
• The hearing can be in person, by phone, or by video
• You can represent yourself or have an attorney or other representative
• Decision timeline: 90 days

ALJ hearings have a strong track record for beneficiaries. Having your doctor testify (even by phone) or submit a written statement can significantly strengthen your case.

Steps 4 and 5: Medicare Appeals Council and Federal Court

Most Medicare appeals are resolved by Level 3. But if you need to go further:

• Level 4 — Medicare Appeals Council: Review of the ALJ decision. File within 60 days. The Council can affirm, reverse, or remand the case.
• Level 5 — Federal District Court: Judicial review for claims meeting the minimum amount in controversy (approximately $1,760 for 2026). This is rare and typically requires an attorney.

Special Medicare Appeal Situations

Hospital discharge appeals

If you're being discharged from a hospital and you believe it's too soon, you have the right to a fast appeal through your Quality Improvement Organization (QIO):

1. Call the QIO listed on the "Important Message from Medicare" notice you received at admission
2. Call by noon of the day after you receive the discharge notice
3. The QIO must decide within 24 hours
4. You cannot be charged for the days you stay while the appeal is pending

Observation status disputes

One of Medicare's most common frustrations: you were in the hospital but classified as "observation" rather than "admitted." This matters because observation stays are covered under Part B (with higher cost-sharing) rather than Part A, and don't count toward the 3-day inpatient requirement for skilled nursing facility coverage.

While you can appeal observation status determinations, Congress has created the MOON (Medicare Outpatient Observation Notice) that hospitals must provide. If you weren't given proper notice, include this in your appeal.

Part D prescription drug appeals

If your Medicare Part D plan denies coverage for a prescription drug:

1. Ask your doctor to file a coverage determination request with your Part D plan
2. If denied, appeal to the Part D plan (Level 1) within 60 days
3. If denied again, your case goes to the Independent Review Entity (IRE)
4. Higher levels follow the same process as other Medicare appeals

Your doctor can also request an exception if the denied drug is medically necessary and formulary alternatives won't work.

The No Surprises Act and Medicare

The No Surprises Act's balance billing protections generally don't apply to Original Medicare because Medicare already has its own protections:

• Participating providers accept Medicare's approved amount as full payment — they cannot balance bill you
• Non-participating providers can charge up to 15% above Medicare's approved amount (the "limiting charge")
• Opt-out providers don't accept Medicare at all — you're responsible for the full cost
• Medicare Advantage plans are subject to some No Surprises Act provisions for emergency and surprise out-of-network care

If a provider who accepts Medicare assignment tries to bill you for more than your deductible and coinsurance, this may violate Medicare rules. Report it to 1-800-MEDICARE.

Getting Help with Medicare Appeals

Medicare beneficiaries have access to several free resources:

• State Health Insurance Assistance Program (SHIP): Free, personalized Medicare counseling. Call 1-877-839-2675 or visit shiphelp.org to find your local SHIP
• Medicare Rights Center: Free helpline at 1-800-333-4114
• Center for Medicare Advocacy: Provides legal analysis and advocacy — medicareadvocacy.org
• 1-800-MEDICARE (1-800-633-4227): Medicare's official helpline — available 24/7
• Area Agency on Aging: Local assistance for seniors — find yours at eldercare.acl.gov or call 1-800-677-1116
• Patient Advocate Foundation: Free case management at patientadvocate.org or 1-800-532-5274

For complex cases or Level 3+ appeals, consider:

• Elder law attorneys: Specialize in Medicare and can represent you at ALJ hearings
• Medical billing advocates: Use Taven's bill review tool to check for billing errors, and consider a professional advocate for complex situations
• Legal aid organizations: Many offer free representation for Medicare beneficiaries

Filing a Complaint

In addition to the formal appeal process, you can file complaints about Medicare:

• 1-800-MEDICARE: For complaints about Original Medicare or Medicare Advantage plans
• Your state insurance department: Find it at naic.org — they can investigate Medicare Advantage plans
• Medicare Ombudsman: Helps resolve Medicare issues and disputes
• Quality Improvement Organization (QIO): For quality of care concerns

Medicare Appeal Checklist

1. Determine whether you have Original Medicare or Medicare Advantage
2. Find your denial on your MSN (Original) or EOB/denial letter (MA)
3. Note the denial reason, deadline, and where to send your appeal
4. For Original Medicare: download CMS Form 20027 from cms.gov
5. Get a letter of medical necessity from your doctor
6. Write your appeal letter using our free appeal template
7. Submit your Level 1 appeal before the deadline
8. Contact your local SHIP for free counseling (1-877-839-2675)
9. If Level 1 is denied, file Level 2 within 180 days (Original) or wait for automatic IRE referral (MA)
10. For Level 3+, consider getting legal help from an elder law attorney
11. Keep copies of everything — all forms, letters, and evidence

The Bottom Line

Medicare's appeal process is more thorough than most private insurers' — with five levels of review, including an independent hearing before an Administrative Law Judge. While the process can feel daunting, the success rates are encouraging, especially at the ALJ level where many beneficiaries have their denials overturned.

The most important steps: act quickly (deadlines are strict), get your doctor's support (a letter of medical necessity is essential), and use the free resources available to you — especially your local SHIP program, which provides personalized, free Medicare counseling.

For more information, read our complete guide to fighting hospital bills or use Taven's bill review tool to check whether you're being overcharged.