3. Test Submission Requirements


The following are frequently asked questions about the DEX™ Diagnostics Exchange Registry and Z-Code™ Program.

Select the ‘Add Test’ action button from the Catalog Overview or My Diagnostics Exchange tabs within DEX. Complete all required fields and submit for review. For more information, see the DEX Diagnostics Exchange Help Files.
When adding a test, use the tooltip buttons to identify required information and view helpful hints. For example, the Test Description should succinctly describe the test’s intended use, indications for ordering, and limitations. PGx tests should include the intended drug(s) of interest in the description.
A DEX Z-Code™ identifier application is required for a single assay that may involve multiple tests in order to produce a single result. Z-Codes are assigned to tests or panels as they are orderable and not based on individual CPT® codes.
If the test process is standardized and the same method is used to acquire results in both locations, lab will only have to submit one application for the test. However, if there is a difference in the method, a separate application will be required for both locations.
It is not necessary to apply for a new Z-Code when you make changes to a test. Please log into DEX and update the existing test record with the new information. If the changes are significant enough to constitute a new test, such as a methodology change or additional specimen types, a new Z-Code may be assigned.
Yes, in the event a test is retired, please update your DEX test submission to reflect this change. The DEX Registry relies on accurate data entry and maintenance. Please review the DEX Administrator FAQs for specific instructions.
Yes, labs must register tests that include MDx and non-MDx range of codes in the test panel.
Both the manufacturer and the performing labs should submit an application. The DEX clinical team will review the applications and assign a Z-Code to the manufacturer’s submission. Each performing lab that submits an application and performs the test without modifications will receive the same Z-Code. Without the application information, it cannot be determined whether or not the kit has been modified and/or how the lab intends to use the kit.
Yes, a Z-Code application is required in both scenarios. The FDA approval process ensures only the clinical and analytical validity of the test. The FDA does not include clinical utility in their review, which is required to establish coverage. If a laboratory modifies an FDA-approved test, the resulting test is considered a LDT (laboratory developed test) and will require a separate application and Z-Code for claims submission.
Yes, an application for a unique identifier will be required if the test has a CPT code within scope for requiring a DEX Z-Code.
We recommend the laboratory wait until the FDA determination is complete to add that information to your test in DEX.
An algorithm may be considered a meaningful and independent component of a laboratory process when ALL the following conditions are met:
  • It is an unambiguous problem-solving operation that includes deploying a set of rules or calculations requiring computer processing;
  • The test result (or a component of the result) is the calculated output of this process, and not an intermediary process;
  • The same or similar test result could not be obtained without the use of this process;
  • The input for the computation is derived from biological samples using analytical processes, and must include data from the sample submitted for the test;
  • The process must:
    • Either be required for the analytical result, OR
    • If adjunct to the analytical result as a post-analytical process, the calculation itself must be independently found to be reasonable and necessary apart from the other components of the test.




3. Test Submission Requirements Articles