If your lab performs molecular diagnostic testing and bills Medicare in a MolDX jurisdiction, Z-Codes aren't optional — they're how the MAC identifies your specific test and determines coverage.
The path to a Z-Code
For each in-scope lab-developed test, you register on the DEX Diagnostics Exchange and submit the test for a Technical Assessment — a review of analytical validity, clinical validity, and clinical utility. If it meets coverage criteria, a CPT code is assigned, and the CPT/Z-Code pair drives reimbursement.
The syndromic panel LCD adds specific coverage rules — including when repeat testing is and isn't covered. Getting registration and documentation right is what turns approved tests into paid claims.