Summary & Overview

CPT 0379U: Solid Tumor Expanded Panel, NGS 523-gene DNA / 55-gene RNA

CPT code 0379U designates a Proprietary Laboratory Analyses (PLA) test for the Quest Diagnostics Solid Tumor Expanded Panel, a next‑generation sequencing (NGS) assay that evaluates DNA across 523 genes and RNA across 55 genes from tumor specimens. This comprehensive panel supports diagnostic clarification, prognostic assessment, and therapy selection for patients with solid tumors, making it an important molecular oncology tool as precision medicine expands nationally.

Key payers in scope for national coverage considerations include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical purpose of the test, typical sites of service, and the service type. The publication summarizes what to expect in payer coverage discussions and benchmarking analyses, highlights implications for clinicians ordering comprehensive NGS panels, and outlines relevant policy and billing considerations tied to PLA-coded, single‑manufacturer tests. Additional sections cover common modifiers and administrative details; where input data is incomplete, the text indicates that specific items are not available in the input.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare0379UCPTProprietary Laboratory AnalysesNGSSolid tumor panelMolecular diagnosticsPrecision oncologyLaboratory testOncology sequencing

Billing Code Overview

CPT code 0379U is a Proprietary Laboratory Analyses (PLA) code that applies only to a single, specific test: the Quest Diagnostics Solid Tumor Expanded Panel. The test is a next-generation sequencing (NGS) targeted sequence analysis of a tumor specimen that evaluates DNA for 523 genes and RNA for 55 genes. Results may inform diagnosis, prognosis, or treatment selection for patients with solid tumors.

Service type: Clinical molecular diagnostic testing using targeted NGS for comprehensive tumor profiling
Typical site of service: Clinical laboratory or independent diagnostic testing facility (specifically performed by Quest Diagnostics)

Clinical & Coding Specifications

Clinical Context

A 62-year-old patient with a biopsy-proven metastatic non–small cell lung carcinoma (NSCLC) presents after progression on first-line systemic therapy. The oncologist orders a comprehensive tumor profiling assay to evaluate DNA and RNA alterations that may guide targeted therapy, immunotherapy eligibility, or clinical trial enrollment. A formal request is placed to Quest Diagnostics for the Solid Tumor Expanded Panel (0379U), which uses next-generation sequencing (NGS) to assess DNA in 523 genes and RNA in 55 genes from the formalin-fixed paraffin-embedded tumor specimen. The clinical workflow includes: pathology confirmation of specimen adequacy, ordering the PLA test in the electronic medical record, completion of required test forms and clinical history, shipping the tumor block or slides to Quest Diagnostics, laboratory extraction and NGS sequencing, bioinformatic analysis and variant interpretation, and reporting of actionable alterations to the treating oncologist. The results inform diagnosis clarification, prognosis estimation, selection of targeted agents or immunotherapies, and identification of clinical trial options.

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier (standard)	Use when no special reporting modifier applies and full test is reported.
`22`	Increased procedural services	Use when the laboratory documents substantially greater complexity, time, or effort for interpretation beyond usual for the PLA.
`26`	Professional component	Use when billing only the professional component (interpretation) separate from the technical component.
`52`	Reduced services	Use when the test is partially performed or limited for clinical/technical reasons.
`53`	Discontinued procedure	Use when testing was started but discontinued due to specimen failure or other valid reason.
`62`	Two surgeons or providers	Rare for PLA; use when two qualified providers share responsibility for interpretation and both must be reported per payer rules.
`78`	Return to the operating/procedural site for a related procedure following initial service	Uncommonly used for PLA; applies if a subsequent specimen is obtained in immediate follow-up procedure related to the initial testing.
`80`	Assistant surgeon	Not typical for lab testing; included when an assistant provider performs a relevant procedural specimen collection billed separately.
`82`	Unusual services by an unqualified resident	Use when interpretation is provided under supervision with documented circumstances per payer policy.
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services for Medicare	Use when one of these non-physician practitioners performs the service components permitted by payer rules.

Taxonomy Code	Specialty	Notes
207RG0100X	Hematology & Oncology	Medical oncologists ordering and interpreting comprehensive tumor profiling.
2085P0207X	Anatomic Pathology	Pathologists responsible for specimen adequacy, testing coordination, and interpretation.
3336C0002X	Molecular Genetic Pathology	Specialists who oversee NGS assay validation, reporting, and variant classification.
363A00000X	Clinical Laboratory	Laboratory directors and molecular diagnostics labs performing the technical assay.
173P00000X	Genetic Counseling	Genetic counselors who provide pre- and post-test counseling for somatic/germline implications.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C34.90`	Malignant neoplasm of unspecified part of unspecified bronchus or lung	Common indication for comprehensive tumor profiling in suspected or confirmed lung cancer to identify targetable alterations.
`C50.912`	Malignant neoplasm of unspecified site of right female breast	Breast cancers frequently undergo expanded genomic profiling to find actionable mutations or for clinical trial eligibility.
`C18.9`	Malignant neoplasm of colon, unspecified	Colorectal cancers are evaluated with broad panels to detect RAS, BRAF, MSI, and other alterations guiding therapy.
`C61`	Malignant neoplasm of prostate gland	Advanced prostate cancers may be tested for DNA repair gene alterations to guide PARP inhibitor therapy.
`C71.9`	Malignant neoplasm of brain, unspecified	Neuro-oncology cases use RNA and DNA profiling for diagnosis, prognosis, and targeted therapy selection.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`88305`	Level IV surgical pathology, gross and microscopic examination (e.g., tumor biopsy interpretation)	Performed prior to `0379U` to confirm tumor diagnosis and document specimen adequacy for NGS.
`88342`	Immunohistochemistry, per single stain	Used for ancillary tumor biomarker testing (e.g., PD-L1) that complements NGS results in treatment selection.
`81432`	Analysis of 5-50 genes by NGS (somatic)	Represents smaller targeted NGS panels that may be ordered instead of or prior to a broad PLA like `0379U`.
`88313`	Special stains, multiple fields, interpretation	Used for additional histochemical studies on tissue to characterize tumor histology before molecular testing.
`99000`	Handling and/or conveyance of specimen to outside laboratory (when applicable)	May be used when specimen is sent to Quest Diagnostics for `0379U` if payer allows billing for specimen transfer handling.

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Summary & Overview

CPT 0379U: Solid Tumor Expanded Panel, NGS 523-gene DNA / 55-gene RNA

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare0379UCPTProprietary Laboratory AnalysesNGSSolid tumor panelMolecular diagnosticsPrecision oncologyLaboratory testOncology sequencing

Billing Code Overview

Service type: Clinical molecular diagnostic testing using targeted NGS for comprehensive tumor profiling
Typical site of service: Clinical laboratory or independent diagnostic testing facility (specifically performed by Quest Diagnostics)

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier (standard)	Use when no special reporting modifier applies and full test is reported.
`22`	Increased procedural services	Use when the laboratory documents substantially greater complexity, time, or effort for interpretation beyond usual for the PLA.
`26`	Professional component	Use when billing only the professional component (interpretation) separate from the technical component.
`52`	Reduced services	Use when the test is partially performed or limited for clinical/technical reasons.
`53`	Discontinued procedure	Use when testing was started but discontinued due to specimen failure or other valid reason.
`62`	Two surgeons or providers	Rare for PLA; use when two qualified providers share responsibility for interpretation and both must be reported per payer rules.
`78`	Return to the operating/procedural site for a related procedure following initial service	Uncommonly used for PLA; applies if a subsequent specimen is obtained in immediate follow-up procedure related to the initial testing.
`80`	Assistant surgeon	Not typical for lab testing; included when an assistant provider performs a relevant procedural specimen collection billed separately.
`82`	Unusual services by an unqualified resident	Use when interpretation is provided under supervision with documented circumstances per payer policy.
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services for Medicare	Use when one of these non-physician practitioners performs the service components permitted by payer rules.

Taxonomy Code	Specialty	Notes
207RG0100X	Hematology & Oncology	Medical oncologists ordering and interpreting comprehensive tumor profiling.
2085P0207X	Anatomic Pathology	Pathologists responsible for specimen adequacy, testing coordination, and interpretation.
3336C0002X	Molecular Genetic Pathology	Specialists who oversee NGS assay validation, reporting, and variant classification.
363A00000X	Clinical Laboratory	Laboratory directors and molecular diagnostics labs performing the technical assay.
173P00000X	Genetic Counseling	Genetic counselors who provide pre- and post-test counseling for somatic/germline implications.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C34.90`	Malignant neoplasm of unspecified part of unspecified bronchus or lung	Common indication for comprehensive tumor profiling in suspected or confirmed lung cancer to identify targetable alterations.
`C50.912`	Malignant neoplasm of unspecified site of right female breast	Breast cancers frequently undergo expanded genomic profiling to find actionable mutations or for clinical trial eligibility.
`C18.9`	Malignant neoplasm of colon, unspecified	Colorectal cancers are evaluated with broad panels to detect RAS, BRAF, MSI, and other alterations guiding therapy.
`C61`	Malignant neoplasm of prostate gland	Advanced prostate cancers may be tested for DNA repair gene alterations to guide PARP inhibitor therapy.
`C71.9`	Malignant neoplasm of brain, unspecified	Neuro-oncology cases use RNA and DNA profiling for diagnosis, prognosis, and targeted therapy selection.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`88305`	Level IV surgical pathology, gross and microscopic examination (e.g., tumor biopsy interpretation)	Performed prior to `0379U` to confirm tumor diagnosis and document specimen adequacy for NGS.
`88342`	Immunohistochemistry, per single stain	Used for ancillary tumor biomarker testing (e.g., PD-L1) that complements NGS results in treatment selection.
`81432`	Analysis of 5-50 genes by NGS (somatic)	Represents smaller targeted NGS panels that may be ordered instead of or prior to a broad PLA like `0379U`.
`88313`	Special stains, multiple fields, interpretation	Used for additional histochemical studies on tissue to characterize tumor histology before molecular testing.
`99000`	Handling and/or conveyance of specimen to outside laboratory (when applicable)	May be used when specimen is sent to Quest Diagnostics for `0379U` if payer allows billing for specimen transfer handling.