Original Medicare Denials: How to Appeal

Written by Aptiva Health Editorial Team · Reviewed by Taylor Sorrels, Esq. and Crystal Brake, RCM Director · Editorial & review standards · How we research

Original Medicare is the federal program run by the government. It is also called Traditional Medicare, or Parts A and B. If Medicare won’t pay for a service you got, you can appeal. The steps are set by federal rules, so they are the same in Kentucky, Indiana and every other state.

This guide explains the five levels of appeal, your deadlines, and two topics that often come up: the WISeR prior authorization model and the Jimmo rule for therapy. It is part of the Coverage & Appeals Center.

If you have a Medicare Advantage plan instead, the steps are different. See Medicare Advantage appeals.

Start with your Medicare Summary Notice

Original Medicare tells you about claims in a Medicare Summary Notice (MSN). It lists each service, what Medicare paid and what it did not. If a service was denied, the MSN explains how to appeal and gives the date you must file by (Medicare.gov: Appeals in Original Medicare).

Keep every MSN. You will need it to appeal. To understand the codes on a denial, try the denial decoder.

The five levels at a glance

Sources: 42 CFR 405.942; 42 CFR 405.962; Medicare.gov; Federal Register: CY2026 amounts.

How the 120 days are counted. The rule counts from when you receive the notice. Medicare assumes you got it 5 days after the date printed on it (42 CFR 405.942). Medicare.gov says to file by the date in your MSN. That is the safest date to use. The appeal deadline calculator can help you track it.

Level 1: Redetermination

A redetermination asks the Medicare contractor that handled your claim to look at it again. You don’t need to owe a minimum amount to ask.

1. Find the denied item on your MSN. Circle the service you disagree with.
2. Choose how to file. Fill out the Redetermination Request Form (CMS-20027), or write on the MSN and attach a letter (CMS-20027).
3. Explain why you disagree. Say in plain words why the service should be paid.
4. Add your name, phone and Medicare Number. Copy them exactly from the MSN.
5. Attach supporting records. Include a letter from your clinician and records that answer the reason for the denial.
6. Send it to the address on your MSN. Keep a copy of everything and proof of sending.
7. Watch for the decision. The contractor generally decides within 60 days.

Level 2: Reconsideration

If you disagree with the Level 1 decision, you can ask a Qualified Independent Contractor (QIC) to reconsider. The QIC is a different company from the one that made the first decision.

• Deadline: within 180 days after you get the Level 1 decision letter (Medicare.gov; 42 CFR 405.962).
• Form: use the Medicare Reconsideration Request Form (CMS-20033), or send a written request (CMS-20033).
• Where to send it: to the QIC listed on your Level 1 decision letter.
• Decision: generally within 60 days.

Send all your evidence at this level.

Levels 3 to 5: Judge, Council and court

• Level 3 — Hearing with a judge. You can ask for a hearing with an Administrative Law Judge at the Office of Medicare Hearings and Appeals (OMHA) within 60 days. In 2026, the amount in dispute must be at least $200.
• Level 4 — Medicare Appeals Council. You can ask the Council to review the judge’s decision within 60 days.
• Level 5 — Federal court. You can file in federal district court within 60 days. In 2026, the amount in dispute must be at least $1,960.

Each decision letter tells you how to ask for the next level.

WISeR: not used in Kentucky or Indiana

WISeR is a CMS test program that adds prior authorization to certain services in Original Medicare only. It runs from Jan. 1, 2026, to Dec. 31, 2031, in six states: New Jersey, Ohio, Oklahoma, Texas, Arizona and Washington (CMS: WISeR Model). Kentucky and Indiana are not included.

The services on the WISeR list include certain nerve stimulators, epidural steroid injections for pain (not facet joint injections), cervical fusion and knee arthroscopy for osteoarthritis (Federal Register: WISeR notice). In WISeR states, licensed clinicians make every recommendation not to pay. If a provider skips prior authorization, the claim gets a review before payment (CMS: WISeR FAQ).

If you live in Kentucky or Indiana but get care in one of those six states, ask that provider whether WISeR applies.

Therapy to keep you from getting worse (Jimmo)

Some denials say you are “not improving” or have “plateaued.” Under the Jimmo settlement, Medicare coverage of skilled nursing and skilled therapy does not depend on whether you can improve. It depends on whether you need skilled care to maintain your function or to prevent or slow decline (CMS: Jimmo Settlement).

• This applies in skilled nursing facilities, home health and outpatient therapy, including physical, occupational and speech therapy.
• Other Medicare coverage rules still apply.
• In inpatient rehab facilities, the maintenance standard does not apply. But coverage should not be denied just because a patient can’t be expected to become fully independent.

If your appeal is about therapy, ask your clinician to explain why skilled care is needed. See getting physical therapy covered.

[Your name]
[Your address] · [Your phone]

[Date]

[Medicare Administrative Contractor name]
[Address from your Medicare Summary Notice]

RE: Request for redetermination
Beneficiary name: [Name]
Medicare Number: [Number from your MSN]
Item or service: [Service]
Date of service: [Date]
Date of the Medicare Summary Notice: [Date]

To whom it may concern:

I disagree with the decision on my Medicare Summary Notice dated [date] to deny payment for [service] on [date of service].

I believe this service was medically necessary and should be covered. My clinician explains why in the enclosed letter.

[If the denial says you are not improving:] I needed skilled care to maintain my function and prevent decline. Medicare coverage does not depend on improvement.

Enclosed are:
- A copy of my Medicare Summary Notice with the item circled
- Letter from [clinician]
- Medical records from [dates]

Please review this claim again and send me your decision in writing.

Sincerely,
[Signature]
[Printed name]

The appeal letter builder can help you fill this in.

Common mistakes

• Using the Medicare Advantage steps. Original Medicare starts with the MSN and a 120-day window, not 65 days.
• Missing the date on the MSN. File by the date printed on your notice.
• Leaving out the Medicare Number. Copy it exactly from the MSN.
• Holding evidence back. Send your clinician’s letter and records early.
• Accepting “not improving.” Ask whether you need skilled care to maintain function.

Where to get help

Not sure which appeal route you’re on? Try the appeal route wizard.