Original MedicarePayer appeals · Medicare Parts A & B (fee-for-service, CMS)

How to appeal an Original Medicare denial

Original Medicare — fee-for-service Parts A and B — has its own five-level appeal, and it doesn’t start with a private plan. It starts with the Medicare contractor that processed the claim, and the first deadline runs from your Medicare Summary Notice.

A denial under Original (fee-for-service) Medicare is appealed through a defined five-level process that is separate from the Medicare Advantage path. Most denials worth appealing are medical-necessity decisions and coverage questions tied to a national or local coverage determination, where the record — mapped to the Medicare rule — is what carries the appeal.

How appeals work at Original Medicare

Original Medicare has five appeal levels. Level 1 is a redetermination by the Medicare Administrative Contractor (MAC), requested within 120 days of the Medicare Summary Notice (42 CFR 405.940). Level 2 is a reconsideration by a Qualified Independent Contractor (QIC). Level 3 is a hearing before an Administrative Law Judge at the Office of Medicare Hearings and Appeals. Level 4 is review by the Medicare Appeals Council, and Level 5 is review in federal district court. The ALJ and federal-court levels carry minimum amount-in-controversy thresholds CMS sets each year ($190 and $1,900, respectively, for 2025). Each level has its own deadline printed on the decision you receive.

What Original Medicare commonly denies

  • Medical necessity (CO-50-type) against a national or local coverage determination.
  • A service or item Medicare treats as not reasonable and necessary as billed.
  • Durable medical equipment or supplies denied on documentation or supplier issues.
  • Coding or billing errors that read as denials but are corrected rather than appealed.

Is a Original Medicare denial worth appealing?

Often worth appealing

Worth appealing medical-necessity and coverage denials when the record can be mapped to the governing Medicare rule (the NCD or LCD the contractor applied). Start with the MAC redetermination within 120 days of the Medicare Summary Notice, and separate true coverage denials from coding errors, which are fixed rather than appealed. The process is multi-level by design — an unfavorable first decision is the start of the ladder, not the end.

How to appeal a Original Medicare denial

  1. 1

    File the redetermination in time

    Request the MAC redetermination within 120 days of the Medicare Summary Notice that shows the denial (42 CFR 405.940).

  2. 2

    Map the record to the NCD or LCD

    Tie the clinical documentation to the national or local coverage determination the contractor cited, criterion by criterion.

  3. 3

    Climb the levels

    If the redetermination is unfavorable, request QIC reconsideration, then an ALJ hearing, the Appeals Council, and — above the amount thresholds — federal court.

Original Medicare — frequently asked

How is appealing Original Medicare different from Medicare Advantage?
Original Medicare starts with a redetermination by the claims contractor (the MAC), due within 120 days of the Medicare Summary Notice. Medicare Advantage starts with a plan reconsideration, generally due within 60 days. The levels above differ too.
How many levels does a Medicare appeal have?
Five: MAC redetermination, QIC reconsideration, an ALJ hearing, the Medicare Appeals Council, and federal court. The ALJ and court levels require the claim to meet a minimum dollar threshold.

Related guides

The five levels of Medicare appealsMedicare Advantage appealCO-50 · medical necessity

Sources

Appeal timeframes and venues are summarized from the federal ERISA/ACA and Medicare Advantage frameworks and vary by plan; payer-specific deadlines and addresses are on your denial notice. Medicare Advantage figures are from KFF's 2024 analysis. This is general information, not legal or coverage advice — confirm the deadline and process on the notice and the plan documents.

When the appeal has to be written, and cited

Upload the denied EOB and Merits returns a complete, citation-verified appeal letter — the clinical argument, the payer's own coverage criteria, and your federal appeal rights — in about a minute.

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