Claims Reporting Unclassified Drugs or Biologicals

Published 02/18/2025

Please use these guidelines when billing HCPCS Code C9399 — Unclassified drugs or biologicals

  • C9399 must be billed with 1 unit
  • The National Drug Code (NDC) for the product must be provided on the claim in the proper format
  • The total dose or quantity of the drug/biological administered must be provided on the claim. The total dose or quantity of the drug/biological must be expressed the unit of measure appropriate for the drug or biological being billed. 
  • When billing for waste, the JW modifier must be used. The total quantity of the drug/biological being billed for waste must also be provided.

If requested, the provider must send additional documentation to support the coverage of the drug or biological being billed as C9399. These claims will then be held in the status/location S MPRC3 while the documents are being reviewed. 

Note: When providing this documentation, please ensure it can be traced back to the claim being processed. Include the DCN of the claim on the coversheet and include the date the documentation was sent in the Remarks section of the claim. If you have multiple dates of service, it is not necessary to send a separate set of documentation for each claim. You may submit a coversheet, reference each claim and send the documentation in once.

Claims with incomplete information will be returned to the provider. Please contact our Provider Contact Center (PCC) with any questions.

  • Jurisdiction J Part A PCC: 877–567–7271
  • Jurisdiction M Part A PCC: 855–696–0705

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