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

Published 10/10/2024

The following 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, we advise you to register your organization on the DEX Registry as soon as possible.

  • UnitedHealthcare®, effective Oct. 1, 2021
  • Optum Care, effective July 1, 2024
  • Humana, effective September 18, 2024

Determine if your test requires a DEX Z-Code:

Review the list of molecular diagnostic CPT® codes within scope for requiring a Z-Code. Please review applicable payer policies for specific CPT® codes. Z-Code requirements may vary by payer.

View a list of all CPT Codes (PDF)

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 listed CPT® codes, your service is due for immediate submission to the DEX Registry for Z-Code assignment.

If you previously registered in DEX and already have an active Z-Code, you can use that code on the claim as instructed by your payer. The test evaluation will be completed based on the information submitted. If the test has outdated or missing information, please update the DEX Registry or Contact Us with questions.

Register your organization:

To register your organization and add tests, navigate to the DEX Diagnostics Exchange Registry. More information on the DEX registration process can be found here.

Add your tests:

  • Submit your test(s) for a Z-Code. More information can be found in the DEX Getting Starting Guide.
    • It takes approximately 2 weeks from test registration to receive a Z-Code.
  • Complete Technical Assessment (TA) documentation, if required.
    • After DEX assigns a Z-Code for a specific test, a TA may be performed, and a result determined at the completion of the assessment.
    • If you are not sure if additional TA documentation is required, please review the Technical Assessment Checklist found on the Technical Assessment page.
    • If you have questions about TA documentation requirements, Contact Us.
  • The Z-Code is effective and can be submitted on claims once the test has been assigned a TA result or has been assigned a recommended CPT® code.
    • For tests that do not require additional TA documentation, this is complete in approximately 3-4 weeks.
    • For tests that have submitted additional TA documentation, this process can take up to 60 days.