I billed multiple patients on one ambulance trip with HCPCS modifier GM, why are my claims still being denied?

Multiple patient transports must be submitted with HCPCS modifier GM on the appropriate ambulance base code and mileage code. 

  • Submit the appropriate origin and destination modifiers in the first modifier position and HCPCS modifier GM in the second modifier position

Documentation required with claims for multiple patient transports:

  • The number of patients transported
  • The Medicare numbers for each Medicare beneficiary in the vehicle at the same time. If there was no other Medicare beneficiary in the vehicle, this must be clearly documented.
  • The total mileage traveled for that individual Medicare beneficiary
  • This information must be in the appropriate documentation record for EDI claims and as an attachment to the CMS-1500 claim form
  • Claims submitted without this information will be rejected as unprocessable and must be resubmitted as new claims


Contact Railroad Medicare

Email Railroad Medicare

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Provider Contact Center: 888-355-9165

IVR: 877-288-7600

TTY: 877-715-6397

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