Remaining Waves Special Notice for Medicare Advantage Providers

Published 12/05/2022

On October 1, 2021, certain national Medicare Advantage Payors began requiring providers to submit DEX Z-Codes™ for molecular diagnostic test services. Other Medicare Advantage Payors may similarly start utilizing and requiring the use of Z-Codes. If you have been notified by your Medicare Advantage Payor 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™ Diagnostics Exchange registry as soon as possible. Please review the requirements below for submitting your molecular diagnostic test services for Z-Code assignment and technical assessment. 

Evaluation and enforcement of Z-Codes will be conducted on a rolling basis in phases (also referred to as waves).  If you already have a Z-Code for your test, you are required to use that code on the claim as instructed by your payor.  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 wave of the rollout.  

Registration Dates for Remaining Code Waves

All waves, except the final wave, has been broken into smaller groups with an additional 30 days to complete that wave of test registrations. The final wave has 60 days to complete as it consists of any MDT test which has not yet been registered in DEX.

Spring registrations Summer registrations Fall registrations
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Third wave - June 15, 2022 Fourth wave - July 1, 2022
Fifth wave - Aug. 1, 2022
Sixth wave - Sept. 2022
Final wave -  Nov. 1, 2022

View a list of all CPT codes by wave (PDF)

Determining if your test requires submission to the DEX Registry for remaining code wave deadlines: 

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. 

The due date for submission for all tests that are defined by or bill with CPT codes for remaining waves are listed here (PDF).  If submissions are not made by the specifed date, you may experience a lapse of coverage or reimbursement for your service. 

Why submit your test(s) before the deadline:  

Reimbursement will only be made for services that demonstrate compliance with existing Medicare policies via a successful technical assessment once the deadline is past. Incomplete submissions or services that otherwise do not demonstrate they meet coverage criteria as defined by relevant Medicare policy will not be reimbursed. 
However, enforcement of Z-Codes and test assessments will not occur until after the deadline.  As a result, submitting your tests as soon as possible: 

  • Allows time to identify and fix possible errors or omissions with your test submission
  • Allows you to possibly identify and remedy test limitations that would preclude coverage under existing policy without loss of reimbursement until the deadline
  • Note: It takes approximately 2 weeks from test registration to receive a Z-Code, however, a technical assessment is required to determine if services meet coverage criteria
    • 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.