How to Appeal an Original Medicare Denial of Coverage or Payment

How do you appeal an Original Medicare denial?

If Original Medicare denies coverage or payment for a medical service, supply or item, the first appeal is called a redetermination. You request this review from the Medicare Administrative Contractor (MAC) responsible for the claim.

Start with your Medicare Summary Notice (MSN). Find the denied claim, check the deadline and follow the appeal instructions on the notice.

You can complete the official Medicare Redetermination Request Form CMS-20027 or submit an acceptable written appeal following your MSN instructions.

The usual first-level filing deadline is 120 days after receipt of the initial determination. The MAC generally issues a decision within 60 days after receiving the appeal.

Before filing, ask your doctor, hospital or supplier for documentation supporting why the service should have been covered or paid.

This procedure applies to Original Medicare Parts A and B. Medicare Advantage and Part D prescription drug appeals follow separate rules.

Which Medicare denials can you appeal?

Original Medicare beneficiaries can challenge initial coverage and payment decisions involving services and items billed under Medicare Part A or Part B.

Examples include a denied medical service, a supply that Medicare refused to pay for, or a payment amount that the beneficiary believes was determined incorrectly.

Medicare also permits appeals when a beneficiary disagrees with the amount they are required to pay for a covered service.

The key question is whether you have an appealable initial Medicare claim determination. A provider's prediction that Medicare may deny a future service is not the same as an actual claim denial.

Original Medicare or Medicare Advantage: Which appeal applies?

Check which program issued the decision before choosing an appeal route.

Do not send an Original Medicare redetermination request to a Medicare Advantage insurer merely because both programs use the Medicare name.

If you have a Medicare Advantage denial that may seriously affect your health, see how to request an urgent Medicare Advantage appeal.

For a denial involving a Part D prescription drug, use the separate Medicare Part D drug appeal procedure.

Where do you find the denied claim and appeal instructions?

Your Medicare Summary Notice (MSN) summarizes processed claims under Original Medicare.

It shows the services and supplies billed to Medicare, what Medicare paid and the maximum amount you may owe the provider.

An MSN is not a bill. It is a record of Medicare's claim determinations and provides instructions for appealing decisions you disagree with.

Review the official Medicare Summary Notice explanation if you are unsure how to interpret it.

What information should you look for?

Identify the following before preparing your appeal:

• The denied item or service.
• The date the service was provided.
• The provider or supplier associated with the claim.
• The explanation of the coverage or payment decision.
• The deadline for filing an appeal.
• The Medicare Claims Office address on the notice.

The last page of the MSN includes appeal instructions and the relevant claims office information.

You can also review processed Original Medicare claims through your secure Medicare account, as explained in the official Medicare claim-status guidance.

How long do you have to file a Medicare redetermination?

For a standard Original Medicare claim appeal, the deadline is generally 120 days from receipt of the initial determination.

CMS explains that the notice is ordinarily presumed received five calendar days after its date unless evidence establishes a different receipt date.

The practical rule is to use the appeal deadline printed on your MSN rather than calculate a later deadline yourself.

Do not wait until the last day to request medical records or prepare your explanation.

What if you missed the 120-day deadline?

CMS permits a late redetermination request when the appellant establishes good cause for missing the deadline.

Medicare identifies circumstances such as a disability, illness or accident that prevented timely filing as possible examples.

If you submit late, explain the reason for the delay and provide any relevant supporting evidence.

Late filing is not automatically excused. The contractor evaluates whether the circumstances justify accepting the request.

Use the official Original Medicare appeals instructions and the directions on your notice.

Which form do you need to appeal?

The standard first-level appeal form is Form CMS-20027, Medicare Redetermination Request Form - 1st Level of Appeal.

Download or review the official CMS-20027 redetermination form.

CMS also permits a written appeal without using this exact form when the request includes the necessary information.

Medicare.gov explains that you may follow the instructions on your MSN by marking the disputed items and explaining in writing why you disagree.

How do you complete Form CMS-20027?

Prepare the following information:

• Your name and Medicare Number.
• The item or service you want reviewed.
• The date the item or service was received.
• The date of the initial determination notice.
• The reason you disagree with the determination.
• Additional information Medicare should consider.
• Your contact details and the identity of the person filing the appeal.

The form provides space to explain why you disagree and whether you have evidence to submit.

CMS requests a copy of the initial determination notice with the form.

If you received the initial notice more than 120 days ago, the form includes a field for explaining the late filing.

Can you appeal without Form CMS-20027?

Yes. Medicare.gov describes a written appeal method using the MSN.

1. Make a copy of your MSN.
2. Circle the specific item or service you want to appeal.
3. Write why you disagree with Medicare's determination.
4. Include your name, address and Medicare Number.
5. Attach any information supporting your position.
6. Send the written appeal to the Medicare Claims Office listed on the MSN.

A written request must identify the claim and provide enough information for the contractor to understand what you are appealing.

Use Form CMS-20027 if you prefer a standardized document that prompts you for the relevant details.

What documents should you include?

Supporting medical information can help the Medicare Administrative Contractor understand why the claim should be covered or paid.

Before submitting, contact the provider or supplier involved in the claim and ask for relevant documentation.

Depending on the denial, useful evidence may include:

• A physician's letter explaining why the service was medically necessary.
• Relevant clinical notes or medical records.
• Documentation supporting the diagnosis or treatment.
• An itemized statement identifying the service.
• Information clarifying an apparent claim error.
• A copy of the MSN or initial determination notice.

Do not assume that every denial requires the same evidence. A dispute about medical necessity differs from a claim with incorrect or incomplete billing information.

What should your appeal explanation say?

Identify the exact claim and explain the specific reason you believe the determination was incorrect.

For example, if Medicare denied payment for a service that your physician considered medically necessary, describe the medical circumstances and include the physician's supporting documentation.

A useful explanation connects the medical evidence to the disputed service rather than simply stating that the denial is unfair.

Do not invent medical details or submit records that do not relate to the claim.

What if the provider billed Medicare incorrectly?

Contact the provider or supplier and ask whether the claim contained incorrect information or omitted required details.

CMS recognizes procedures for correcting certain minor errors and omissions without using the formal appeals process.

However, do not assume that asking the provider to correct a claim automatically extends your appeal deadline.

If the deadline is approaching, follow the MSN appeal instructions while working with the provider to resolve the billing issue.

Where do you send a Medicare redetermination request?

Send the written appeal to the Medicare Administrative Contractor (MAC) responsible for the initial claim determination.

The relevant mailing address is listed in the appeal instructions on your MSN.

Medicare.gov directs beneficiaries using the MSN appeal method to the Medicare Claims Office address shown on the last page of the notice.

Because contractors and addresses vary, there is no single nationwide mailing address for every Original Medicare redetermination.

Use the official Original Medicare appeal instructions and your own MSN.

Can you file the first appeal online?

Medicare.gov provides a downloadable redetermination form and instructions for submitting a written appeal to the responsible MAC.

There is no single nationwide beneficiary online application identified in the official Original Medicare redetermination instructions.

Some contractor processes may offer additional submission methods. Use only the method specified by the MAC responsible for your claim.

Downloading a PDF or viewing your claim online does not by itself submit an appeal.

Can a family member or representative file for you?

You can appoint a trusted person to represent you in a Medicare appeal.

The appointed representative may be a family member, friend, attorney or another person who meets Medicare's representation requirements.

Medicare.gov directs appellants to include the Appointment of Representative form or another written instrument containing the required elements when an appointed representative files the appeal.

The official Original Medicare appeal page provides access to the Appointment of Representative form.

Providing informal help with organizing records is different from formally acting as an appointed representative.

How long does the first Medicare appeal take?

The Medicare Administrative Contractor generally issues a redetermination decision within 60 days after receiving the appeal.

The redetermination is conducted by MAC personnel who were not involved in the initial claim determination.

The contractor reviews the claim and the relevant information provided for the appeal.

There is no guarantee that the original denial will be reversed.

If Medicare changes the decision

When the MAC determines that Medicare should cover or pay the appealed service, the result may appear on a subsequent Medicare Summary Notice.

Review the updated claim information to understand what Medicare paid and whether any remaining beneficiary responsibility applies.

A favorable appeal does not necessarily mean every amount billed by the provider becomes payable by Medicare.

If Medicare denies the appeal

If the MAC does not reverse the disputed decision, it issues a written Medicare Redetermination Notice explaining the result.

The notice provides information about further appeal rights.

Read the explanation carefully. It may identify missing medical evidence or a coverage issue that should be addressed in the next appeal.

What if the first Medicare appeal is denied?

You can generally request a second-level appeal called reconsideration by a Qualified Independent Contractor (QIC).

The QIC did not participate in the first-level determination.

Medicare.gov states that you generally have 180 days after receiving the MAC's redetermination decision to request reconsideration.

Use the instructions in the Medicare Redetermination Notice. The request should identify the disputed items or services, explain why you disagree and include supporting evidence.

The QIC generally issues a decision within 60 days after receiving the reconsideration request.

Review the official Original Medicare reconsideration guidance for the appropriate form and submission route.

Is reconsideration the same as filing another redetermination?

No. A redetermination is the first review by the Medicare Administrative Contractor.

A reconsideration is the next appeal level, conducted by a Qualified Independent Contractor.

If you receive an unfavorable redetermination, follow the second-level instructions instead of sending another first-level request for the same disputed determination.

Include the relevant decision notice and address any missing documentation identified in the first appeal.

How far can a Medicare appeal go?

Original Medicare has five appeal levels. The first two do not require the minimum disputed-dollar amount that applies at certain later levels.

For 2026, Medicare.gov identifies a $200 minimum amount in controversy for level-three review and a $1,960 minimum for federal district court judicial review.

These thresholds do not apply to the initial redetermination or second-level reconsideration.

Each later appeal level has its own filing instructions and deadlines. The decision notice from the previous level explains how to proceed.

This procedure focuses on the first appeal and the immediate next step if the first appeal is unsuccessful.

When should you use another Medicare appeal process?

Some Medicare disputes require a different route or have different deadlines.

A hospital or facility says your covered care is ending

Medicare provides special fast-appeal rights for certain situations in which covered services are ending.

These may involve hospitals, skilled nursing facilities, home health agencies, comprehensive outpatient rehabilitation facilities or hospice services.

Your provider must give you a written notice explaining the fast-appeal procedure and applicable deadline.

Do not rely on the ordinary 120-day claim-appeal deadline when a fast termination appeal applies. The deadline on the special notice may be much shorter.

Use the instructions provided with the termination notice and the official Medicare appeals overview.

A hospital changed your inpatient status to observation

Medicare has a separate appeal process for certain patients whose hospital status changed from inpatient to outpatient observation.

Eligibility depends on specific circumstances, including the hospital admission and status change.

Medicare.gov explains this special process separately from the ordinary redetermination procedure.

If your dispute concerns a hospital-status change, consult the official hospital-status appeal guidance.

What mistakes can delay or weaken your appeal?

• Missing the MSN deadline: use the appeal date on the notice and file promptly.
• Appealing the wrong claim: identify the exact service and date being disputed.
• Sending the request to the wrong office: use the MAC or Medicare Claims Office identified on the MSN.
• Using the wrong program's appeal process: Medicare Advantage and Part D have separate procedures.
• Providing no explanation: state why the determination should be changed.
• Leaving out relevant medical evidence: ask the provider for information supporting the claim.
• Assuming a provider billing correction stops the appeal deadline: protect your appeal rights while the billing issue is investigated.
• Failing to document representative authority: include the required appointment information when another person represents you.
• Ignoring a late-filing explanation: if filing after the deadline, provide the reason and evidence supporting good cause.
• Repeating the first appeal after a denial: use the second-level reconsideration process when appropriate.

Example: Medicare denies payment for a medical service

A beneficiary receives an MSN showing that Original Medicare denied payment for a service performed by their physician.

The beneficiary checks the appeal deadline and asks the physician's office whether the claim contains an error or whether the service was denied under a coverage rule.

The physician provides a written explanation of why the service was medically necessary, along with relevant clinical documentation.

The beneficiary completes Form CMS-20027, identifies the service and date, explains the disagreement and attaches the supporting records.

The appeal is sent to the MAC identified on the MSN before the deadline.

If the MAC upholds the denial, the beneficiary reviews the Medicare Redetermination Notice and decides whether to request reconsideration by a QIC.

The outcome depends on the claim and supporting evidence; submitting an appeal does not guarantee payment.

Where can you get help filing your appeal?

The Centers for Medicare & Medicaid Services (CMS) administers the Medicare program, while Medicare Administrative Contractors conduct first-level Original Medicare claim appeals.

Use these official resources:

• Original Medicare appeals guide.
• Medicare Redetermination Request Form CMS-20027.
• CMS first-level redetermination guidance.
• Medicare Summary Notice information.

For questions about your appeal rights, call 1-800-MEDICARE (1-800-633-4227). TTY users can call 1-877-486-2048.

Medicare also identifies the State Health Insurance Assistance Program (SHIP) as a source of free, personalized Medicare counseling.

Before submitting, confirm the disputed claim, appeal deadline, correct MAC address and supporting evidence. Keep copies of the documents you send and any decision notices you receive.