Original Medicare appeal checklist

Confirm the appeal route

• Verify that the decision is from Original Medicare, not Medicare Advantage, another Medicare health plan, or a Part D plan.
• Confirm that the dispute concerns a processed Part A or Part B item or service.
• Ask the provider whether a minor error or missing claim information can be corrected and resubmitted without an appeal.
• Check whether a fast appeal or a special hospital-status process applies instead.

Record the deadline and address

• Copy the appeal date from the last page of the MSN.
• Copy the MAC name and claims-office address exactly.
• If filing electronically, use only the official MAC website and save its submission instructions.
• Plan enough time to obtain proof that the request was sent or received.

Gather the claim information

• Medicare Summary Notice and the page showing the disputed item.
• Beneficiary name, address, and Medicare number.
• Provider or supplier, item or service, and date of service.
• Provider bill, receipts, and relevant insurance statements.
• Medical notes, order, letter, or other evidence that supports coverage when available.

Prepare the written request

• Choose the appeal instructions on the MSN or official Form CMS-20027.
• Circle or clearly identify each item or service being appealed.
• Explain why the coverage or payment decision is wrong.
• List every attachment and keep originals unless the instructions require otherwise.
• Include representative documentation when another person is formally acting for the beneficiary.

Before sending

• Check that the Medicare number and service dates are accurate.
• Make a complete copy of the signed or submitted request and all evidence.
• Remove unrelated personal or medical information that the appeal does not require.
• Use the MAC destination on the MSN, not a general CMS address.

After filing

• Save the mailing receipt, fax confirmation, or electronic confirmation.
• Respond promptly if the MAC requests more information.
• Watch for the redetermination notice; CMS says the decision is generally issued within 60 days after receipt.
• If the decision is unfavorable, read the level 2 reconsideration instructions and deadline immediately.

Official sources

• Medicare.gov — Original Medicare appeals
• CMS — first-level redetermination
• CMS — Form CMS-20027

Related resources

• Step-by-step Original Medicare appeal
• Original Medicare appeal deadline
• Review claims and the Medicare Summary Notice
• Medicare redetermination definition