CurrentColorado Rocky Mountain Health PlansPolicy N/A

Molecular Diagnostic Test (MDT) billing with DEX Z-Code®

Policy governs submission and reimbursement requirements for molecular diagnostic tests billed to UnitedHealthcare Community Plan Medicaid, including mandatory reporting of Palmetto DEX Z-Code identifiers alongside CPT/HCPCS codes for claims on CMS-1500 and UB04 forms.

Policy Summary

PayerColorado Rocky Mountain Health Plans

PolicyMolecular Diagnostic Test (MDT) billing with DEX Z-Code®

Policy CodePolicy N/A

Change TypeState list updatesguidance edits

Effective DateN/A

Next Review DateN/A

Key ActionSubmit the Palmetto DEX Z-Code® adjacent to the CPT/HCPCS code and enter 1 unit of service.

SourceLink

POLICY UPDATE CHANGES

Tennessee updated and State Specific Lists added for Tennessee (Rapid Genetic Testing codes).

State Exceptions: Kansas Removed.

State Exceptions: Missouri Added.

State Exceptions: Maryland Added.

Reimbursement Guidelines, Definitions, and Q&A sections updated (02/01/2025).

UB-04 & CMS-1500forms this policy applies to

5-characterformat of DEX Z-Code identifiers

1unit of service to enter for MDT claims

DEX Z-Code requiredidentifier required with molecular pathology CPTs

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Coverage Criteria for Molecular Diagnostic Tests

MDT reimbursement criteria

Reimbursement will be considered when claims include the appropriate CPT/HCPCS and the Palmetto DEX Z-Code® identifier reported in the specified claim fields and adhere to submission rules.

Provider must report the CPT/HCPCS code that most accurately describes the specific test performed and the corresponding DEX Z-Code® identifier.

Enter 1 unit of service for MDT claims (per CMS national coding only one unit may be reported when a single procedure is performed).

ALL of the following

For professional claims: Loop 2400 (SV-101-7) for electronic 837P or Box 19 for paper CMS-1500.
For facility claims: Line SV-202-7 for electronic 837I or Block 80 on the UB-04.

For panels that analyze multiple genes but produce a single result, submit a single CPT and a single DEX Z-Code®; duplicate or multiple CPTs with the same Z-Code for the same patient/date will be denied.

Operational notes

Register tests in the Palmetto DEX® registry to obtain DEX Z-Code® identifiers; the performing laboratory's Z-Code is used for billing.
If a reference laboratory performs the test, the performing lab's Z-Code should be used for billing and arrangements must be made for sharing the identifier as appropriate.

Services described in this policy may be subject to additional UnitedHealthcare reimbursement policies (e.g., CLIA ID Requirement, Laboratory Services, Add-On, Maximum Frequency, Rebundling, CCI Editing).

Fallback coding: If no specific code applies, use unlisted molecular pathology code 81479 mapped with the appropriate DEX Z-Code® registration details.

Coding and Unit Reporting

Fallback codeCPT

81479

Unlisted molecular pathology procedure (used when no other code applies)

Units per Single Procedure (MDT)

Unit of service to report1 unit per single MDT procedure (per CMS national coding only one unit may be reported when a single procedure is performed)

When additional specimen is distinctAn additional code may be reported with an appropriate modifier for a separate specimen tested the same date, supported by requisition/documentation

Modifier useModifiers should not be used to report multiple codes when a single specimen is tested

Provider Billing Actions and Requirements

Billing Rule

Claim submission of DEX Z-Code

Claim Submission of DEX Z-Code: Providers must report Molecular Diagnostic Tests (MDT) and molecular pathology services with the appropriate CPT/HCPCS code that most accurately describes the specific test performed and the corresponding Palmetto DEX Z-Code® identifier. Submit the DEX Z-Code® adjacent to the CPT/HCPCS code on claims to support reimbursement determinations. More information and registration are available at https://app.dexzcodes.com.

Professional claims: include the DEX Z-Code® in Loop 2400 SV-101-7 on the 5010A1 837P or in Box 19 on a paper CMS-1500 claim.
Facility claims: include the DEX Z-Code® in Line SV-202-7 on the 837I electronic claim or in Block 80 on the UB-04 claim form.
Enter 1 unit of service (UOS) when reporting the molecular pathology CPT code.

Definitions

Molecular Pathology — Definition

DefinitionMolecular pathology procedures are laboratory analyses of nucleic acids (DNA/RNA) to detect gene variants indicative of germline or somatic conditions or to test for histocompatibility antigens (e.g., HLA)

ScopeIncludes analyses for detection of variants that may indicate constitutional disorders or neoplasia

Relation to MDT codesDescribed by molecular pathology/MDT CPT codes in the molecular pathology series (80000 series)

DEX Z-Code® Identifiers — Definition & Format

Identifier formatUnique 5-character alpha-numeric code assigned within the DEX® Diagnostics Exchange

Issuing bodyAssigned and maintained by Palmetto GBA via the DEX® registry

Denial Risk

Multiple procedure reporting

Multiple procedure reporting: When testing involves multiple genes but produces a single result from a single specimen, submit one CPT code (Tier 1, Tier 2, PLA, GSP, or when applicable 81479) and a single DEX Z-Code® representing that test. Do not report duplicate or multiple molecular pathology CPT codes with the same DEX Z-Code® for the same patient on the same date of service; such duplicates will be denied. If distinctly separate specimens are tested for different indications on the same date of service, the initial specimen is reported without a modifier and an additional code for the additional specimen may be reported with an appropriate modifier supported by documentation.

Report one CPT and one DEX Z-Code® when multiple genes/components produce a single test result.
UnitedHealthcare will deny duplicate/multiple CPTs reported with the same DEX Z-Code® for the same patient and date of service.
Modifiers should not be used to report multiple codes for a single specimen; CMS national correct coding limits one unit when a single procedure is performed.

Note

DEX registration and sharing

DEX registration and sharing: Laboratories must register their organization and tests in the Palmetto DEX® Diagnostic Exchange to obtain a DEX Z-Code®. The performing laboratory receives the Z-Code used for billing; if a reference lab performs the test, both organizations should register in DEX® and use the DEX® sharing workflow so the billing provider can obtain access to the performing lab's Z-Code®. If the same standardized test is performed at multiple locations using the same method, a single application may be submitted; differing methods at different locations require separate applications.

Register organization: https://www.dexzcodes.com → DEX® Registry → 'Register My Organization'.
Performing lab submits test details and is assigned the Z-Code; billing provider must use the performing lab's Z-Code.
Use DEX® 'Sharing Request' when tests are performed by a reference lab to obtain access to the performing lab's Z-Code.
All components of a panel should be registered; DEX® will map only tests in scope for this policy.