Commercial Plans Current CPT® Codes and Z-Code® Registrations for Molecular Diagnostic Testing

DEX® Participating payers will require a Z-Code obtained from the DEX® Diagnostics Exchange Registry to be added to claims for molecular pathology services. Claims may be denied if the Z-Code information is missing, invalid, or does not match the service represented by the CPT® code reported on the claim.

Z-Code Requirements for Molecular Testing:  View a list of CPT codes (PDF)

What to expect after you complete your registration:

• The initial review for Z-Code assignment takes approximately 2 weeks from test submission.
  • If you require a Z-Code from a reference lab, please refer to the DEX Getting Started Guide
• Additional Technical Assessment (TA) documentation may be required dependent on test complexity and TA evaluation procedure established. If your test is identified as requiring additional TA documents, you will receive an email from DEX. For more information, refer to DEX - 4. Technical Assessment (TA) Evaluation
• The Z-Code can be submitted on claims once you have received email notification that the test has been assigned a recommended CPT code
  • For tests that do not require additional TA documentation, or we have not received the required documentation, this will be completed in approximately 3 - 4 weeks.
  • For tests that have submitted additional TA documentation, this process can take up to 60 days.
• Some services may not have a TA evaluation procedure in place yet. These tests will be updated with a recommended CPT code and a Non-Medicare TA Result of N/A and can submitted on claims with the appropriate Z-Code and CPT code. If the test type is determined to be part of a future TA evaluation requirement, you will be notified when additional documentation are required. Please see below for TA documentation requirements below to learn more.

Technical Assessment (TA) Documentation Requirements:

• NEW: As of April 1, 2026 Palmetto GBA will be requesting TA documents for fetal red blood cell (RBC) antigen genotyping. Tests previously submitted for prenatal cell-free DNA screening that included RBC genotyping in the service are now eligible to submit combined Z-Codes for their services.
  • If you have not yet received a Z-Code for your fetal RBC antigen genotyping test and are currently providing that service and billing one of the below CPT codes, your service is due for submission to the DEX Registry for Z-Code assignment. 

• TA Evaluation Procedures in Place:
  • Exome and Genome sequencing
  • Prenatal cell-free DNA Screening
  • Venous Thromboembolism Risk and Hereditary Thrombophilia Testing
  • Diagnosis and High-Risk Inherited Cancer Panel
  • Prenatal Carrier Screening tests
  • Molecular diagnostic tests that are relevant to the Medicare age population (age 65+)

Have more questions?

• If you have any questions or are not sure if your test requires submission now or in the future, please visit the DEX Website for more information or contact customer service at DEX.Customer.Service@PalmettoGBA.com.
• Upcoming communications will alert you to additional CPT code lists, services required additional TA documentation and timing.
• For questions specific to UnitedHealthcare Policy please contact United_Genetics@UHC.com.