CurrentUnitedHealthcarePolicy 2025R7135A

Submission of DEX Z-Code® with Molecular Pathology/Molecular Diagnostic Claims

This UnitedHealthcare Community Plan reimbursement policy requires providers to submit Palmetto DEX Z-Code® identifiers together with the appropriate CPT/HCPCS codes for molecular pathology and molecular diagnostic tests on UB-04/CMS-1500 claims; it applies to all products and providers submitting claims to UnitedHealthcare Community Plan Medicaid.

Policy Summary

PayerUnitedHealthcare

PolicySubmission of DEX Z-Code® with Molecular Pathology/Molecular Diagnostic Claims

Policy CodePolicy 2025R7135A

Change TypeNo material changes

Effective Date

Next Review Date

Key ActionRegister tests in the Palmetto DEX® Diagnostic Exchange and report the 5-character DEX Z-Code® on claims along with the appropriate CPT/HCPCS code.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

every Molecular Pathology Coderequires submission of a DEX Z-Code®

UB-04 and CMS-1500forms covered by this policy

one CPT + one DEX Z-Codesingle-result multi-gene tests

states excluded listedstate exceptions

registration via Palmetto DEX®

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how to obtain Z-Code

Reimbursement Requirements

Reimbursement criteria for molecular pathology/MDT claims

Reimbursement is contingent on claim submission meeting the following documentation and coding requirements:

ALL of the following

Required identifier
- Provider must submit the Palmetto DEX Z-Code® identifier with each molecular pathology or MDT CPT/HCPCS code on the claim.
- UnitedHealthcare Community Plan requires providers to submit a DEX Z-Code® with every Molecular Pathology Code submitted for these services to be considered for reimbursement.
Providers must report the CPT and/or HCPCS code(s) that most accurately describe the specific test performed as assigned through the Palmetto DEX® registry.
Register tests in the Palmetto DEX® Diagnostic Exchange and obtain the unique 5-character DEX Z-Code® for each molecular diagnostic test performed; report that Z-Code on claims in addition to the appropriate CPT/HCPCS code.
For tests that analyze multiple genes producing a single result, submit one CPT code and one DEX Z-Code®; duplicate or multiple molecular pathology CPT codes reported with the same DEX Z-Code® for the same patient and date of service will be denied.
If using a reference laboratory, the performing laboratory must obtain the Z-Code and share it in DEX® so the billing provider can use the performing provider's Z-Code.
When separate specimen(s) are tested on the same patient on the same date of service for distinctly separate indications, report the initial specimen without a modifier and report an additional code for the additional specimen with an appropriate modifier supported by documentation; per CMS National Correct Coding policy, only one unit of service may be reported when a single procedure is performed, and modifiers should not be used to report multiple codes for a single specimen.
All services may be subject to other UnitedHealthcare reimbursement policies (e.g., CLIA ID requirement, Laboratory Services Policy, Add-On Policy, Maximum Frequency Per Day Policy, Rebundling Policy, CCI Editing Policy).
Certain states are excluded from this policy (see state exceptions).

Documentation to support use of modifiers for multiple specimens must be available (e.g., test requisition and clinical documentation).

Code Reporting and Units

Unlisted/Not Otherwise ClassifiedCPT

81479

Unlisted molecular pathology procedure (use when no other code is applicable)

inv-03: Units per single specimen

Units per single specimenPer CMS National Correct Coding policy, only one unit of service may be reported when a single procedure is performed on a single specimen; modifiers must not be used to report multiple codes for a single specimen.

Separate specimens same dayIf separate specimen(s) are tested on the same patient same date for distinctly separate indications, report the initial specimen without a modifier and report the additional specimen with an appropriate modifier supported by documentation.

Documentation requirement for modifiersUse of a modifier to identify a different indication on the same date of service must be supported by the test requisition form and documentation.

Registration, Billing Rules, and Reference Lab Procedures

Billing Rule

Single-result multi-gene testing billing rule

Providers must submit one CPT code and the corresponding Palmetto DEX Z-Code® for tests that involve multiple genes but produce a single result. 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 submissions will be denied.

Submit a single CPT and matching DEX Z-Code® for single-result multi-gene tests
Duplicate/multiple CPTs with the same Z-Code® for same patient/date will be denied

Billing Rule

Reference lab Z-Code sharing

When a performing (reference) laboratory obtains the Palmetto DEX Z-Code® for a test, the performing lab must share that Z-Code® in the DEX® registry so the billing provider can access and use it. Both the billing provider and the performing lab must register as organizations in DEX®. The billing provider should request a Sharing Request in DEX® to obtain access to the performing lab's Z-Code®; the billing provider must use the performing provider's Z-Code® on claims.

Key Terms

inv-07: Molecular Pathology

DefinitionMolecular pathology procedures are medical 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 tests that identify variants relevant to constitutional disorders, neoplasia, or other clinically significant genetic findings.

Relation to MDTsMolecular pathology is the category encompassing molecular diagnostic tests described in CPT molecular pathology codes (80000 series).

inv-08: DEX Z-Code® Identifiers

Identifier formatDEX Z-Code® Identifiers are unique proprietary 5-character alphanumeric codes assigned within the Palmetto DEX® Diagnostics Exchange.

PurposeUsed to identify specific molecular diagnostic tests in the Palmetto DEX® registry to facilitate billing and reimbursement.

Policy Summary

PayerUnitedHealthcare

PolicySubmission of DEX Z-Code® with Molecular Pathology/Molecular Diagnostic Claims

Policy CodePolicy 2025R7135A

Change TypeNo material changes

Effective Date

Next Review Date

Key ActionRegister tests in the Palmetto DEX® Diagnostic Exchange and report the 5-character DEX Z-Code® on claims along with the appropriate CPT/HCPCS code.

SourceLink

On This Page

Performing lab submits test details and receives the Z-Code®
Billing provider requests 'sharing' in DEX® to access and use the performing lab's Z-Code® on claims
Providers only request Z-Codes for tests performed in-house; billing providers use the performing lab's Z-Code®

Billing Rule

DEX Z-Code® registration and reporting

Register tests in the Palmetto DEX® registry and obtain a unique 5-character Z-Code® for each test. Report the assigned CPT and/or HCPCS code that most accurately describes the specific molecular diagnostic test performed along with the Z-Code® on the claim so UnitedHealthcare can determine the exact test performed for reimbursement.

Register organization and tests at https://www.dexzcodes.com (Select DEX® Registry > Register My Organization)
Report the Z-Code® in field 2400 SV-101-7 (Professional), SV-202-7 (Institutional) on electronic claims or in the shaded area of service line in section 24 on paper claims
All components of custom panels should be registered; DEX® will map tests in scope for the policy

Assignment and accessCodes are assigned through registration in the DEX® registry administered by Palmetto GBA; performing and billing providers must coordinate Z-Code sharing when reference labs are used.

inv-09: Molecular Diagnostic Test (MDT)

DefinitionA Molecular Diagnostic Test (MDT) is a test involving detection or identification of nucleic acids (DNA/RNA), proteins, chromosomes, enzymes, cancer chemotherapy sensitivity, and/or other metabolites; may include multiple components or algorithms.

Test compositionAn MDT may consist of a single mutation analysis or include multiple components and may rely on algorithmic data evaluation or derivation.

Relation to coding/registryMDTs fall within the scope of the Palmetto DEX® registry and are described by molecular pathology CPT codes (80000 series) for billing and identification purposes.