Summary & Overview
HCPCS G9291: Specimen Site Other Than Lung, NSCLC–NOS
HCPCS Level II code G9291 identifies a diagnostic pathology specimen taken from a site other than the lung when the lesion is not classified as non–small cell lung cancer or is recorded as NSCLC–NOS. This code matters nationally because accurate coding of specimen origin and tumor classification affects claims processing, clinical registries, cancer surveillance, and appropriate downstream billing and care coordination for oncology patients. Key payers included in the analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will gain a concise understanding of the code’s clinical and administrative purpose, where the service is typically provided, and the implications for national billing and reporting workflows. The publication outlines benchmarks and contextual guidance on documentation elements relevant to correct use of G9291, discusses typical sites of service such as hospital outpatient departments and pathology laboratories, and highlights how the code interfaces with oncology diagnostic pathways. Data not available in the input is noted where applicable, including associated taxonomies, specific ICD-10 diagnoses, related codes, and service line details.
Billing Code Overview
HCPCS Level II code G9291 denotes a specimen site other than the anatomic location of the lung that is not classified as non–small cell lung cancer (NSCLC) or is classified as NSCLC–NOS (not otherwise specified). The description indicates this code is used when the specimen originates from a site distinct from the lung itself and the pathology or classification does not clearly fit established NSCLC subtypes.
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Service type: Diagnostic pathology specimen classification
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Typical site of service: Hospital outpatient departments, pathology laboratories, and specialized oncology diagnostic centers
Clinical & Coding Specifications
Clinical Context
A 64-year-old patient with a prior history of a lung mass undergoes a biopsy of a metastatic lesion located outside the lung (for example, a liver or bone biopsy) after imaging suggests an extrathoracic metastasis. The surgical pathology report indicates the specimen site is not the anatomic location of lung and the tumor cannot be classified as non-small cell lung cancer (NSCLC) or is reported as NSCLC-NOS (not otherwise specified). The clinical workflow includes: pre-procedure imaging (CT, PET), percutaneous or image-guided core needle biopsy of the extrathoracic lesion, specimen submission to pathology with clinical history noting a pulmonary primary or suspected lung origin, immunohistochemistry and molecular testing as needed, pathology interpretation documenting that the specimen is not from the anatomic lung and that classification as NSCLC is indeterminate or recorded as NSCLC-NOS, and communication of results to the treating oncologist for staging and treatment planning.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | When work performed is substantially greater than typically required (e.g., unusually complex biopsy or extended time for image-guided extrathoracic specimen retrieval). |
23 |