## Definition
The Healthcare Common Procedure Coding System code G6004 pertains to a service related to radiation treatment delivery. Specifically, it is defined as “Stereotactic body radiation therapy (SBRT), treatment delivery, per treatment course, to 1 or more lesions, including image guidance, entire course not to exceed 5 fractions.” This code is used when delivering stereotactic body radiation therapy, which is a type of external beam radiation therapy that precisely targets tumors while sparing healthy surrounding tissue.
Stereotactic body radiation therapy is often employed in cases where precise delivery is crucial, such as small, well-defined tumors. This HCPCS code accounts for the delivery of up to five fractions, or treatment sessions, over the entirety of the course. Proper use of this code requires strict adherence to the outlined treatment protocol and the number of prescribed fractions.
## Clinical Context
Stereotactic body radiation therapy, billed under the code G6004, is frequently employed in the treatment of cancers, particularly for tumors in locations such as the lungs, liver, spine, and pancreas. This highly precise treatment modality allows for concentrated radiation to small, isolated sites, reducing collateral damage to adjacent healthy tissue. Oncology professionals generally recommend this therapy for inoperable or difficult-to-reach tumors, or when traditional radiation therapy would be too risky for surrounding tissues.
In clinical practice, the decision to use stereotactic body radiation therapy is determined after a thorough assessment of the patient’s condition, tumor characteristics, and overall prognosis. Radiologists and radiation oncologists collaborate to develop a treatment plan that includes the necessary imaging guidance during the therapy course. Because the entire treatment comprises five or fewer fractions, the total radiation dose administered in each fraction is often higher than in conventional radiation therapy, necessitating precise planning and execution.
## Common Modifiers
Healthcare providers may need to append various modifiers to HCPCS code G6004 to reflect specific circumstances of the care provided. The most frequent modifier used with this code is Modifier 26, which signifies that only the professional component of the service was provided. This may occur when the interpreting physician reviews the treatment plan at a location remote from where the actual treatment delivery took place.
Additionally, Modifier TC is applicable when hospitals or facilities report only the technical component for the stereotactic body radiation therapy. This modifier is placed on a claim when a provider is responsible solely for providing the equipment, supplies, and technical expertise required to deliver the therapy, without accounting for the professional services. Properly appending these modifiers is essential to ensure appropriate reimbursement.
## Documentation Requirements
Proper documentation is critical when submitting claims that include HCPCS code G6004. Clinicians are expected to provide thorough notes detailing the treatment plan, rationale for using stereotactic body radiation therapy, tumor location, and the number of treatment fractions. The inclusion of supporting imaging, such as CT or MRI records, is often required to substantiate the necessity of image guidance during therapy.
Similarly, documentation must note the total radiation dose administered over the course of the treatment and provide evidence of clinical supervision during each fraction. Details regarding patient positioning, immobilization techniques, and daily set-up verification should also be incorporated into the record to ensure that medical necessity is accurately supported. Without clear documentation, insurance providers are likely to deny claims or request additional information.
## Common Denial Reasons
One of the most frequent reasons for claim denial associated with HCPCS code G6004 is incomplete or insufficient documentation. Insurance providers may reject claims if there is a lack of evidence supporting the use of stereotactic body radiation therapy, such as absent imaging studies or omitted rationale for the chosen treatment modality. Failure to justify the treatment plan, including the number of fractions delivered, is often scrutinized in these situations.
Another common denial reason stems from improper use of modifiers, particularly when the professional or technical components are not adequately separated. In instances where both the TC and 26 modifiers are omitted or incorrectly applied, claims may be flagged for improper billing. Additionally, denials may occur when the treatment course exceeds the maximum allowable five fractions, which is a specific limitation associated with this code.
## Special Considerations for Commercial Insurers
When billing commercial insurance carriers, special attention must be given to the payer’s policies as they often differ from federal programs such as Medicare. Some commercial insurers may require preauthorization for stereotactic body radiation therapy, particularly when submitting claims under HCPCS code G6004. Failure to obtain prior authorization could result in a denial of payment, as many insurers mandate review of high-cost therapies prior to treatment.
Additionally, commercial insurers may have different requirements for documentation, modifiers, and coding practices compared to Medicare or Medicaid. Providers must carefully review insurer-specific coverage policies and allowable charges to ensure the claim complies with their criteria. Commercial insurers may also apply more stringent review processes for emerging technologies such as stereotactic body radiation therapy, particularly if its use extends to indications beyond those widely accepted in clinical guidelines.
## Similar Codes
There are several other HCPCS and Current Procedural Terminology codes that describe related services and may require careful consideration to avoid incorrect billing. For instance, HCPCS code G6015 represents “Intensity-modulated radiation therapy (IMRT), delivery, simple; includes image guidance.” Like stereotactic body radiation therapy, intensity-modulated radiation therapy is a form of precision-guided radiation therapy, but it involves different technical and procedural components.
Another related code is 77373, which describes the delivery of stereotactic body radiation therapy in accordance with different fractionation schemes or technical settings. Though both 77373 and G6004 may describe similar treatments, their use is keyed to distinct billing scenarios depending on the payer’s coding mandates. Similarly, providers might consider codes G6016 for advanced image guidance procedures in conjunction with radiation therapy planning when circumstances require another code in addition to G6004.