Summary & Overview
HCPCS G0173: Linear Accelerator Stereotactic Radiosurgery, Single Session
HCPCS Level II code G0173 represents linear accelerator based stereotactic radiosurgery (SRS) delivered as a complete course in one session. This single-fraction, high-precision radiotherapy procedure is used for select intracranial and certain extracranial targets where a one-time focused dose is clinically appropriate. Nationally, SRS delivered with linear accelerators is an important modality for oncology and neurosurgical practices because it enables outpatient, noninvasive treatment options that can reduce hospital stays and target lesions with submillimeter accuracy.
Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for SRS with linear accelerators, expected sites of service, and the scope of services captured by G0173. The publication also provides benchmarks and comparative payment context where available, summarizes relevant policy considerations from major payers, and outlines common clinical coding relationships. Data elements not provided in the input are indicated as unavailable. This summary is intended for national audiences including hospital administrators, radiation oncologists, billing managers, and policy analysts seeking a clear reference for HCPCS Level II code G0173.
Billing Code Overview
HCPCS Level II code G0173 describes linear accelerator based stereotactic radiosurgery, complete course of therapy in one session. This service type is stereotactic radiosurgery (SRS) delivered using a linear accelerator platform and represents a complete therapeutic course provided in a single treatment session. The typical site of service is an outpatient radiation oncology facility or a hospital-based radiation therapy department where linear accelerator equipment is located.
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Clinical & Coding Specifications
Clinical Context
A 62-year-old patient with a solitary 2.2 cm metastatic brain lesion from non-small cell lung cancer presents for definitive intracranial stereotactic radiosurgery. The multidisciplinary workflow includes a radiation oncology consultation, pre-procedure imaging (contrast-enhanced MRI and planning CT), immobilization with a thermoplastic head frame or frameless mask, treatment planning using high-resolution target delineation and dosimetry on a linear accelerator-based stereotactic radiosurgery (SRS) platform, and a single-session delivery of a high-dose conformal or volumetric arc therapy guided by image guidance. The encounter includes physician evaluation for candidacy, simulation and immobilization, treatment planning and physics quality assurance, and a single treatment session using a linear accelerator delivering stereotactic precision radiation under image guidance. Typical sites of service are a hospital outpatient radiation oncology department or an ambulatory radiation center equipped with a high-precision linear accelerator. Payors commonly involved include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA, and Medicare.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing separately for physician interpretation/planning distinct from facility technical services |
59 |