Dual-Eligible (Medicare and Medicaid) Claim Denied: How to Appeal

Dual-eligible beneficiaries — people who qualify for both Medicare and Medicaid — should have the most comprehensive coverage available. In practice, they face some of the most complex and frustrating denial situations in the entire health insurance system. Coordination of benefits errors, wrong primary payer determinations, managed care plan failures, and cost-sharing disputes create a maze that leads to claims falling through the cracks. Here is how to fight back.

Why Dual-Eligible Claims Get Denied

Wrong primary payer determination. Medicare is almost always primary for dual-eligible beneficiaries; Medicaid is the payer of last resort. When a provider bills Medicaid first (or a managed care plan processes the claim incorrectly), denials follow. The claim may be denied by Medicaid because Medicare should have been billed first, or denied by Medicare with cost-sharing that Medicaid should cover.

Medicare Advantage plan denials. Many dual-eligible beneficiaries are enrolled in Dual Eligible Special Needs Plans (D-SNPs) — Medicare Advantage plans designed for dual-eligibles. These plans have their own Prior Authorization Denied: How to Appeal" class="auto-link">prior authorization requirements, network rules, and formularies. Denials from D-SNPs follow Medicare Advantage appeal rules, which are different from original Medicare rules.

Medicaid not picking up cost-sharing. One of the core benefits of dual eligibility is that Medicaid generally covers Medicare's cost-sharing (deductibles, copays, and coinsurance) for full dual-eligibles (FBDE). When providers bill patients for this cost-sharing, or when Medicaid denies the cost-sharing claim, this violates the dual-eligible beneficiary's rights.

Formulary and prior authorization disputes. Drug coverage through Medicare Part D may deny a medication that is covered under Medicaid, or a D-SNP may impose prior authorization requirements that exceed what is allowed for dual-eligibles.

Low-Income Subsidy (LIS) not applied. Dual-eligible beneficiaries automatically qualify for the Medicare Part D Low-Income Subsidy (LIS/Extra Help), which eliminates or dramatically reduces prescription drug cost-sharing. If the plan is not applying LIS correctly, this is a billing and enrollment error.

Medicaid state plan services denied. Some services are covered by Medicaid but not Medicare (dental, vision, long-term care, personal care attendants). These are governed by state Medicaid rules and are appealed through the Medicaid system, not Medicare.

Your Legal Rights

Medicare appeal rights. For original Medicare denials, you have five levels of appeal: redetermination by the Medicare Administrative Contractor (MAC), reconsideration by a Qualified Independent Contractor (QIC), ALJ hearing at the Office of Medicare Hearings and Appeals (OMHA), Medicare Appeals Council review, and federal district court. Deadlines apply at each level — generally 120 days from the denial notice.

Medicare Advantage appeal rights. D-SNP and other Medicare Advantage plan denials must be appealed through the plan first (organization determination), then to the Independent Review Entity (IRE), then through the same ALJ/appeals council/court pathway as original Medicare. Expedited appeals are available when standard timelines would jeopardize health.

Medicaid fair hearing rights. If Medicaid coverage is denied, reduced, or terminated, you have the right to request a state Medicaid fair hearing. You generally have 90 days to request a hearing. If you request a hearing before the effective date of a termination or reduction, Medicaid must continue your benefits at the current level while the hearing is pending (aid-pending status).

Dual-eligible protections. Federal regulations (42 C.F.R. § 423.800 and related provisions) impose specific requirements on Medicare Part D plans serving dual-eligible beneficiaries, including automatic LIS enrollment, prohibited cost-sharing, and required transition fills. Violations can be reported to CMS.

CMS oversight. The Centers for Medicare and Medicaid Services (CMS) has a dedicated Office of Minority Health and a dual-eligible coordination program. Systemic coordination of benefits failures can be reported to the State Health Insurance Assistance Program (SHIP) or CMS directly.

Step-by-Step Appeal

Step 1: Identify which program denied the claim. The denial notice should come from either Medicare (or your Medicare Advantage plan) or Medicaid. This determines your appeal pathway.

Step 2: Identify the specific denial reason. Common reasons include: not medically necessary, prior authorization required, provider not enrolled in the program, coordination of benefits error, formulary exclusion, or coverage exclusion.

Step 3: Contact your SHIP counselor. The State Health Insurance Assistance Program provides free counseling to Medicare beneficiaries. SHIP counselors specialize in helping dual-eligibles navigate complex coverage situations and can help you identify the correct appeal process.

Step 4: File the appropriate appeal.

• For Medicare denials: file a redetermination request within 120 days of the denial notice
• For Medicare Advantage (D-SNP) denials: file an organization determination appeal within 60 days
• For Medicaid denials: request a state fair hearing within the deadline specified in your notice (typically 90 days)

Step 5: Gather clinical documentation. Regardless of which program denied the claim, have your physician document:

• The specific diagnosis (with ICD-10 codes)
• Medical necessity of the denied service or medication
• Prior treatments tried and their results
• Why the denied service is necessary for this patient

Step 6: Address coordination of benefits errors. If the denial resulted from a coordination of benefits mistake (wrong primary payer), contact both the Medicare plan and the Medicaid plan, provide the correct primary/secondary payer information, and request reprocessing of the claim.

Documentation Checklist

Before filing your appeal, gather:

• Denial notice from Medicare, Medicare Advantage, or Medicaid (with denial reason)
• Your Medicare card, Medicaid card, and any D-SNP plan card
• EOB (Explanation of Benefits) or Medicare Summary Notice (MSN)
• Physician letter documenting medical necessity
• Diagnosis codes (ICD-10) and procedure codes (CPT/HCPCS) from the denied claim
• Records showing prior treatment history
• Evidence of LIS enrollment (if a Part D drug denial)
• Contact information for your SHIP counselor

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Related Reading

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