HCPCS Modifier GZ

Published 07/16/2020

Item or service expected to be denied as not reasonable and necessary and an Advance Beneficiary Notice (ABN) has not been signed by the beneficiary.

Guidelines and Instructions

  • Submit HCPCS modifier GZ when there is no valid ABN on file for a service that you expect Medicare will deny as not reasonable and necessary
  • Effective July 1, 2011, claim lines containing HCPCS modifier GZ will be automatically denied and will not be subject to complex medical review
  • HCPCS modifier GZ may not be submitted with services that are statutorily excluded. Refer to HCPCS modifier GY for these services.

ABN Background

  • Both Medicare beneficiaries and providers have certain rights and protections related to financial liability under the Fee-For-Service (FFS) Medicare and the Medicare Advantage (MA) Programs. These financial liability and appeal rights and protections are communicated to beneficiaries through notices given by providers.
  • All providers are required to use the CMS ABN form, available on the CMS website
  • The ABN form must be presented to the patient before the service or procedure is initiated. Maintain a copy of the form in the patient’s medical record.


  • CMS ABN (Form CMS-R-131) and instructions for completion

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