Medicare as Secondary Payer

Published 12/19/2023

Yes. Unless you have been approved to submit hard copy claims to Medicare, submit all Medicare claims electronically, including Medicare Secondary Payer (MSP) claims. An exception to this requirement is when a patient has two or more payers who are primary to Medicare. In situations where Medicare is the tertiary payer, these claims may be submitted hard copy.

The ASC v5010 format allows for electronic submission of primary payer information for MSP claims. Palmetto GBA also offers the PC-ACE Pro32 EDI billing software, which supports electronic submission of MSP claims.

Last Reviewed: 12/19/2023

Medicare Secondary Payer (MSP) refers to instances in which Medicare does not have primary responsibility for paying the medical expenses of a Medicare beneficiary. This is because the Medicare beneficiary may be entitled to other coverage, which should pay the primary health benefits.

Medicare secondary claims can be submitted electronically. However, Palmetto GBA has rejected some claims because there was a mismatch between the MSP type submitted on the claim and the specific patient's Medicare record. Below are some examples of situations that you may wish to verify when you receive these Medicare rejections:

  • Do you routinely submit claims containing the same MSP type (example: MSP type 47) when Medicare does not show this to be a valid MSP type for the specific patient?
  • If you submit your claims to a clearinghouse, does your clearinghouse understand that claims must be submitted with the correct MSP type?
  • Is your patient covered by Medicare as an Aged Worker (Type 12), but claims for the patient are being submitted as Disability (Type 43)?
  • Was your patient's injury related to Workers' Compensation (Type 15), but you submitted the MSP claim as an Aged Worker (Type 12)?
  • If you submit claims through an electronic clearinghouse, make sure you provide the clearinghouse with the correct MSP type for each claim. If you are still receiving rejections from Medicare, verify that your clearinghouse is submitting the MSP type you provided for each patient.

If you answered "Yes" to any of the above questions, your Medicare MSP claims are most likely rejecting because there is a mismatch of the type submitted and the Medicare MSP files. This situation can drastically impact the cash flow for your office. Below are the loops and segments where this information should be located in the electronic claims format:

Loop, Segment, Element Description Value
2000B, SBR, 05 Insurance Type Code 12, 13, 14, 15, 41, 43, 47
  • Always submit the appropriate MSP type for the beneficiary's insurance coverage
  • If the submitted MSP type does not correspond to the information Medicare has on file, your claim will be rejected. Rejected claims must be submitted as new claims.

Below is a list of the valid Medicare Secondary Payer types that may be submitted on electronic claims.

MSP Type Description
12 Working Aged: age 65 or over, employer's group plan has at least 20 employees
13 End Stage Renal Disease (ESRD): 30-month initial coordination period in which other insurer is primary
14 No-Fault Situations: Medicare is secondary if illness/injury results from a no-fault liability. This type would most likely not be submitted to Palmetto GBA because we will pay services conditionally, as primary, based on your decision to submit the claim to Medicare for the Liability situation. In these cases, we do not require MSP information.
15 Workers' Compensation (WC) situations
41 Black Lung benefits
43 Disability: under age 65, person or spouse has active employment status and employer's group plan has at least 100 employees
47 Liability Situations: Medicare is secondary if illness/injury results from a liability situation

Last Reviewed: 12/19/2023

No. The EDI fax process can only be used to submit supporting documentation (e.g., office notes, operative reports, patient history and physical, or other medical records) with initial electronic claim submissions. However, the 5010 format does allow for electronic submission of primary payer information for MSP claims. Palmetto GBA also offers the PC-ACE Pro32 EDI billing software, which supports electronic submission of MSP claims.

Last Reviewed: 12/19/2023

There are times when a provider will receive a primary payment from another insurance company after Medicare has paid as primary. When this happens, it is assumed that Medicare should be the secondary payer. If you receive two primary payments, you should refund Medicare’s payment in full.

  • Refund the Medicare payment to Palmetto GBA within 60 days of the date you identify the overpayment, even if Medicare’s records show that Medicare is primary
    • Send a copy of the other insurer’s Explanation of Benefits (EOB) and the Overpayment Refund form with your check. The Overpayment Refund Form is available on our website under Forms tab at the top of the web page.
    • If you send a refund without the primary insurer’s EOB, Palmetto GBA may apply the refund to any other accounts receivable for that provider or provider group
    • After Palmetto GBA processes and applies your refund, you may resubmit the claim as a Medicare Secondary Payer claim
    • After 30 days, you may call the provider contact center (PCC) to verify the refunded status. Note: The Interactive Voice Response (IVR) System will not specify that the claim was refunded. The status will reflect processed and paid.
  • Although we will deposit your check almost immediately, it may take as long as 30 days for the status of the claim to show a refund status. Please do not resubmit your claim before we have applied the refund to the original claim, otherwise the new claim will deny as a duplicate.
  • Remember, you can obtain claim status information through the IVR at any time
  • If Medicare records show that Medicare is primary for the patient, Palmetto GBA will request that these records (Common Working File [CWF] records) be updated to reflect that Medicare is secondary. The MSP Contractor will update the records.
    • Please note that updates to CWF records can take up to 100 days
    • To avoid additional overpayments while Medicare’s records are being updated, file all subsequent claims for that patient with the payment information (EOB) from the primary insurer
  • A good resource for understanding when Medicare pays primary or secondary is available on the Palmetto GBA website refer to the MSP Lookup Tool 

Reference: CMS IOM Publication 100-05, Chapter 3, Section 10.4 (PDF).

Last Reviewed: 12/19/2023

If the claim is within the one year timely filing period and Medicare Part B has not made a secondary payment for the date of service
Resubmit the claim and if the MSP Contractor information has been updated showing Medicare as primary, the claim will process accordingly.
If the claim is within the one year timely filing period and Medicare Part B has already made a secondary payment for the date of service
Appeal the initial claim payment within 120 days from the date of the initial determination. Submitting a new claim would not be appropriate since it would deny as a duplicate.
If the primary recoups past the timely filing limit
Appeal the Medicare claim once you file the claim to Medicare and receive the timely filing denial. Include information explaining why the claim was not filed timely. It will be reviewed based on the individual circumstances and documentation submitted.

Last Reviewed: 12/19/2023

The timely filing requirement for primary or secondary claims is one calendar year (12 months) from the date of service. Providers should follow up with primary insurers if there is a delay in processing that may result in going past the Medicare timely filing limit.

Last Reviewed: 12/19/2023

The MSP Contractor has CMS directives regarding which pieces of MSP information can be updated by a provider. Most items require the patient to update the information. You do have the option of doing a three-way call with the patient to help assist getting the patient to update their information. In some cases on a three-way call with the patient and MSP Contractor the patient can give the call center representative permission to speak with you and update the information.

Last Reviewed: 12/19/2023

If you have submitted a claim and received a denial indicating that the claim is related to a no-fault or WC case, you can submit an appeal explaining that the services are non-related.

Last Reviewed: 12/19/2023

There are two reasons your claim may have rejected. You must correct and resubmit the rejected claim with valid and necessary information for adjudication of your claim.

Reviewing the issues below will assist in resolving rejections with Remark Code MA04: "Secondary payment cannot be considered without the identity of or payment information from the primary payer. The information was either not reported or was illegible."

  • Issue: Palmetto GBA will reject a claim when there was a mismatch between the MSP type submitted on an electronic claim and the specific patient's Medicare record
    • Palmetto GBA has implemented new MSP messaging to assist providers in quickly identifying claims that have rejected for incorrect MSP type based on information Medicare has on file. The new messaging is effective for claims processed on and after February 27, 2019. You will see CARC P6 and RARC N541 for these situations.
    • Claim Adjustment Reason Code P6, Reason and Remark Code N541: Mismatch between the submitted insurance type code and the information stored in our system
  • Resolution
    • Review the Palmetto GBA article Valid MSP Types for Electronic Claims to assure the patient’s MSP type billed on your electronic clam is valid for the individual patient’s MSP type
    • Review the Palmetto GBA article Are Your Medicare Secondary Payer (MSP) Claims Rejecting? for proper placement of the MSP indicator on your claim
    • Make any necessary corrections to the patient’s MSP type and resubmit your claim
  • Issue: When billing electronically, you must provide details regarding how the primary insurer handled the patient’s claim
  • Resolution
    • The ASC v5010 format allows for electronic submission of primary payer information for MSP claims using the correct loops and segments
    • Review the Palmetto GBA article Electronic Submission of MSP Claims for proper claim submission of MSP payment information
    • Make any necessary corrections to the claim to provide the required information and resubmit the claim

Review the Palmetto GBA Medicare Secondary Payer (MSP) web page for additional MSP resources and the Washington Publishing Company website for Reason and Remark code descriptions.

Last Reviewed: 12/19/2023

Are you unsure if Medicare should pay as the primary or secondary insurer for your patient? Use our MSP tool to answer your questions and find your solutions. The questionnaire is easy and quick to use for all of your patients.

Before You Begin: Facts to Know

  • For patients that have both Medicare and Medicaid and no other insurance, Medicare is the primary payer
  • In most cases, federal law takes precedence over state laws and private contracts. Even if a state law or insurance policy states that they are a secondary payer to Medicare, the MSP regulations should be followed to determine the correct primary payer.
  • Medicare records may not reflect the patient's current insurance status. If you find that there is a discrepancy between Medicare records and the patient's current insurance status, call the MSP Contractor at 855–798–2627 or TDD/TYY 855–797–2627. The MSP Contractor may also need to speak to the patient. However, providers are permitted to call.
  • In some cases, if a patient or his/her spouse is working and is covered by an employer group health plan (EGHP), you must know the number of people employed by the company in order to use this tool most effectively. Either you or the patient may contact the employer to obtain this information.
  • Providers are required to file claims on behalf of their Medicare patients, including patients for whom Medicare is the secondary payer
  • These claims must be filed electronically, unless you qualify for a waiver to submit paper claims

Last Reviewed: 12/19/2023

If the primary payer for the service continues to recognize consultation codes, physicians and others billing for these services may either:

  • Submit an evaluation and management (E/M) code that is appropriate for the service to the primary payer and then report the amount actually paid by the primary payer, along with the same E/M code, to Medicare for determination of whether a payment is due
  • Submit a claim to the primary payer using a consultation code that is appropriate for the service and then report the amount actually paid by the primary payer, along with an E/M code that is appropriate for the service, to Medicare for determination of whether a payment is due

Last Reviewed: 12/19/2023


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