Medicare Part B Claim Denied: How to Appeal and Win

Receiving a Medicare Part B denial can feel overwhelming, especially when you are already managing a health condition and expected your insurance to cover your care. Medicare Part B covers outpatient services: doctor visits, diagnostic tests, durable medical equipment, preventive care, outpatient therapy, and mental health services. The good news is that Medicare beneficiaries have a robust, federally guaranteed five-level appeals process — and a significant number of denials are overturned when patients submit the right documentation and push back at the right level.

Why Medicare Part B Claims Are Denied

Medicare Part B denials cluster around several recurring categories. The most common is failure to meet medical necessity criteria established in Local Coverage Determinations (LCDs) or National Coverage Determinations (NCDs) published by CMS. LCDs specify, for each service type, the clinical conditions that must be documented — including specific ICD-10 diagnosis codes — for Medicare to consider the service reasonable and necessary. A claim billed under ICD-10 code M54.5 (low back pain) may be denied for a procedure that requires documentation of a more specific diagnosis code (such as M47.816 for spondylosis with radiculopathy) to meet the applicable LCD criteria.

Outpatient therapy services (physical therapy CPT codes 97110, 97530; occupational therapy 97165-97168) are denied when documentation does not establish that the therapy requires the skills of a licensed professional or does not show measurable functional improvement goals. Preventive screenings are denied when they are billed as diagnostic rather than preventive, or when the beneficiary's record does not meet the applicable screening eligibility criteria. Mental health services (ICD-10 F32-F33 major depressive disorder, F41.1 generalized anxiety disorder) face denials when documentation of treatment plans and medical necessity is insufficient. Durable medical equipment claims are denied when the supplier fails to submit documentation meeting the equipment-specific LCD requirements. Advance Beneficiary Notices (ABNs) create additional complexity when they are used incorrectly or when a beneficiary signs an ABN without understanding the billing implications.

How to Appeal a Denied Medicare Part B Claim

Step 1: Review Your Medicare Summary Notice and Identify the Denial Reason

Your Medicare Summary Notice (MSN) lists all claims processed during a period, including denied claims and the reason codes for each denial. Review the MSN carefully to identify the specific reason your claim was denied, the amount in dispute, and the service date. If a provider billed on your behalf, contact them to obtain the same information from the Remittance Advice they received. Identify the applicable LCD or NCD for the denied service at cms.gov — this document specifies exactly what documentation is required.

Step 2: File a Redetermination (Level 1) Within 120 Days

Submit a written redetermination request to the Medicare Administrative Contractor (MAC) that processed your claim within 120 days of the date on your MSN. Include your name, Medicare number, the specific claim at issue, and a written explanation of why you believe the claim should be covered. Attach supporting documentation: physician notes, diagnostic test results, medical records, and any documentation that addresses the specific LCD criterion the claim failed to meet. The MAC must issue a redetermination decision within 60 days.

Step 3: Request a Qualified Independent Contractor (QIC) Review (Level 2)

If the MAC upholds the denial, escalate to a Qualified Independent Contractor within 180 days of the redetermination decision. The QIC provides genuinely independent clinical review, applying Medicare coverage criteria without deference to the MAC's original decision. Submit any additional clinical evidence not available at the prior level — updated physician notes, a new supporting letter from your physician specifically addressing the denial reason with reference to the applicable LCD, or specialist consultation records. The QIC must respond within 60 days.

Step 4: Request an ALJ Hearing (Level 3)

If the QIC upholds the denial and the amount in dispute meets the minimum threshold ($180 in 2025), request an Administrative Law Judge hearing through the Office of Medicare Hearings and Appeals (OMHA) within 60 days of the QIC decision. ALJ hearings are conducted independently and give you the opportunity to present testimony and additional evidence directly. Beneficiaries who participate in hearings — in person, by video, or by telephone — have significantly higher success rates than those who submit a decision on the written record alone. Prepare a clear, written brief addressing each denial reason and organize your supporting documents into a coherent exhibit set.

Step 5: Escalate to the Medicare Appeals Council and Federal Court

If the ALJ rules against you, request review by the Medicare Appeals Council (60-day deadline from the ALJ decision). The Appeals Council is a component of the Departmental Appeals Board within HHS. If the Appeals Council upholds the denial and the amount in dispute meets the threshold ($1,870 in 2025), you may file a civil action in federal district court within 60 days. Legal representation is strongly recommended at this level.

Step 6: Strengthen Your Record Throughout the Process

Use Medicare's denial language in your appeal and refute each stated reason directly. Cite the applicable LCD in your favor — if the LCD supports coverage for your specific diagnosis and clinical situation, quote it explicitly in your appeal letter. Request that your physician add a detailed supporting letter to your medical record that maps your clinical situation to the specific Medicare coverage criteria. Submit all documents via certified mail with return receipt and keep complete copies of everything.

What to Include in Your Appeal

• Medicare Summary Notice (MSN) with the specific denial reason code and amount in dispute
• The applicable Local Coverage Determination (LCD) or National Coverage Determination (NCD) document
• Physician letter specifically addressing the denial reason and the applicable LCD criteria, with ICD-10 codes
• Medical records, specialist notes, diagnostic test results, and any functional assessment reports
• Documentation of treatment plan goals and measurable outcomes (for therapy service denials)
• Prior Authorization Denied: How to Appeal" class="auto-link">Prior authorization or referral records, if applicable

Fight Back With ClaimBack

Medicare Part B denials for outpatient therapy, diagnostic tests, mental health services, and durable medical equipment are highly technical — knowing the applicable LCD and framing your physician documentation to address its specific criteria is the difference between approval and a second denial. ClaimBack generates a professional appeal letter in 3 minutes. Start your free claim analysis → Free analysis · No credit card required · Takes 3 minutes

Related Reading

• How to Write an Insurance Appeal Letter
• What Is Medical Necessity?
• Internal vs External Insurance Appeal