Current CPT® Codes and Z-Code® Notice for Medicare Advantage Providers

Published 06/28/2024

Select national Medicare Advantage payers are participating with the DEX® Diagnostics Exchange Registry and requiring providers to submit DEX Z-Codes® for molecular diagnostic test services. If you have been notified by your Medicare Advantage payer that this applies to your billed services, you are subject to this notice and are urged to comply with the instructions below.

To avoid potential loss of coverage or reimbursement for molecular diagnostic tests, we advise you to register your organization on the DEX Registry as soon as possible. Please review the requirements below for submitting your molecular diagnostic test services for Z-Code assignment and technical assessment.

If you already have a Z-Code for your test, you are required to use that code on the claim as instructed by your payer. If you do not yet have a Z-Code for your test, then you must determine if your test requires submission to the DEX Registry at this time based on the current list of CPT® codes.

Determining if your test requires submission to the DEX Registry:

If you have not yet received a Z-Code for your molecular diagnostic test and are currently providing that service and billing one of the below CPT codes, your service is due for immediate submission to the DEX Registry for Z-Code assignment.

View a list of all CPT Codes (PDF)

Note: It takes approximately 2 weeks from test registration to receive a Z-Code, however, a technical assessment is required to determine if services have demonstrated compliance with relevant standards.

  • For tests that do not require additional documentation, this is complete in approximately 3-4 weeks.
  • For more complex testing requiring technical assessment documentation review, the process will take additional time.