Submitting Secondary Claims to Medicare: A Guide to Crossover Billing with EOBs

Disclaimer: Billing regulations and guidelines, particularly those that are state-specific, are subject to frequent changes. Providers should always consult the latest official CMS resources and their respective state Medicaid or Medical Assistance program websites and provider manuals for the most current and accurate information.

Understanding Secondary Claims and Crossover Billing

For healthcare providers, submitting secondary claims accurately is crucial for proper reimbursement when a patient has more than one insurance plan. After Medicare (the primary payer) processes a claim, the remaining balance, including deductibles and coinsurance, is often passed to a secondary insurer. This guide outlines the essential steps for submitting these secondary claims, with a particular focus on Medicare/Medicaid crossover billing, utilizing the Explanation of Benefits (EOB) or Electronic Remittance Advice (ERA).

Medicare Secondary Payer (MSP) Rules

Medicare Secondary Payer (MSP) rules determine which insurance plan pays first when a beneficiary has Medicare and other coverage. Understanding MSP is fundamental to compliant secondary billing. Medicare may be secondary to employer group health plans, workers’ compensation, no-fault insurance, or other government programs. The MSP rules dictate the order of benefits, ensuring that claims are processed correctly by the responsible payer first. For detailed information, always refer to official CMS guidance on Medicare Secondary Payer.

Understanding Your Explanation of Benefits (EOB) or Electronic Remittance Advice (ERA)

After Medicare processes a claim, providers receive an Explanation of Benefits (EOB) or an Electronic Remittance Advice (ERA). These documents detail what Medicare paid, the amount adjusted, and the patient’s responsibility (deductible, coinsurance). Beneficiaries receive a Medicare Summary Notice (MSN), which serves a similar purpose for their records. The information on your EOB or ERA is vital for accurately submitting a secondary claim. It’s important to note that while you might occasionally encounter the informal term “ecob”, often a misspelling, the correct and official terms are Explanation of Benefits (EOB) for paper and Electronic Remittance Advice (ERA) for electronic transactions.

Medicare-Medicaid Crossover Billing Steps

When a patient is eligible for both Medicare and Medicaid (Medical Assistance), the process is known as Medicare-Medicaid crossover billing. In most cases, if a provider accepts assignment on the Medicare claim (Box 27 on the CMS-1500), Medicaid (Medical Assistance) will pay the Medicare coinsurance and/or deductible amounts, less any other third-party payments (e.g., Medigap).

To ensure accurate cross-referencing and payment:

• Provider Identification: Ensure your Medicare provider number and National Provider Identifier (NPI) are correctly linked within your state’s Medicaid system. If you need to add, change, or delete information, contact your state’s Medicaid fiscal agent or claims processing unit.
• State-Specific Guidelines: Each state’s Medicaid program has specific guidelines for crossover claims. Providers must refer to their state’s Medicaid fiscal agent website or provider manual for detailed procedures, current contact information, and specific claims addresses. For example, providers billing Maryland Medical Assistance should consult the official Maryland Department of Health website for current provider manuals and contact details.

Electronic Secondary Claim Submission (EDI)

Electronic Data Interchange (EDI) is the predominant method for submitting secondary claims today, offering efficiency and faster processing. After Medicare processes the primary claim and you receive the ERA, the data from the ERA is electronically transmitted with the secondary claim to the patient’s secondary insurance.

Key steps for EDI secondary claims:

• Your practice management software or billing clearinghouse will typically extract the necessary payment and adjustment information from the Medicare ERA.
• This data, along with the original claim information, is formatted into an electronic secondary claim (often an 837P transaction for professional claims).
• The electronic claim then indicates that Medicare was the primary payer, detailing the Medicare payment and patient responsibility.
• It’s crucial to ensure your billing system correctly maps the Medicare EOB/ERA data into the appropriate fields for the secondary payer to prevent denials.

Hardcopy CMS-1500 Secondary Claim Submission

While EDI is preferred, hardcopy submission using the CMS-1500 form may still be necessary in certain situations. When submitting a hardcopy claim with a Medicare EOB:

Each individual claim on the Medicare EOB is typically designated by horizontal lines. You should complete one CMS-1500 form per distinct claim indicated on the EOB.

Important Considerations for the CMS-1500:

• Information Matching: The data on the CMS-1500 must precisely match the information between the horizontal lines on the Medicare EOB.
  • Dates of service must match exactly.
  • Procedure codes must match.
  • The “amount billed” on the EOB must match the total charges (Box 24F) on the CMS-1500.
• Primary Insurance Information (Box 29): In Box 29 of the CMS-1500, enter the amount Medicare paid.
• Remaining Balance: Calculate the remaining balance (charges minus Medicare payment) and clearly indicate it, typically in Box 29 or a designated section for the secondary payer.
• Legibility and Attachments: Ensure all writing on the CMS-1500 is legible. When attaching a copy of the Medicare EOB, make sure it is clear, complete, and includes all relevant sections, such as the top information and the glossary. The CMS-1500 and the Medicare EOB must be submitted together for Medicaid/Medical Assistance to pay for coinsurance and deductibles.

Claims should be sent to the appropriate claims address as specified in your state’s Medicaid provider manual. Avoid using outdated or specific individual contact information. Instead, refer to official state resources for current mailing addresses.

Avoiding Secondary Claim Denials and Appeals

Secondary claim denials can arise from various issues. Here are common reasons and tips for prevention:

• Inaccurate Data Entry: Ensure all patient demographics, dates of service, procedure codes, and diagnostic codes precisely match the primary EOB/ERA.
• Missing or Illegible EOB/ERA: Always attach a clear copy of the primary payer’s EOB or ensure the ERA data is correctly submitted electronically.
• Incorrect Payer Information: Verify the secondary payer’s correct address and claim submission requirements.
• Timely Filing Limits: Adhere strictly to the secondary payer’s timely filing limits, which typically run from the date of the primary payer’s EOB/ERA.

If a secondary claim is denied, review the denial reason carefully. Often, re-submitting with corrected information or appealing with additional documentation (e.g., a clearer EOB copy or a letter explaining the discrepancy) can resolve the issue. Emphasize accurate data entry and meticulous review of all documents before submission to minimize denials.