Summary & Overview
HCPCS Level II S9991: Services for Phase III Clinical Trial
HCPCS Level II code S9991 designates services provided as part of a Phase III clinical trial. This code captures clinical care and associated trial-related services delivered during late-stage investigational studies, which are critical for evaluating safety and efficacy before potential regulatory approval. Nationally, accurate use of this code supports appropriate tracking of clinical trial services, billing transparency, and payer coverage decisions.
Key payers referenced in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of how S9991 is used in billing for Phase III research care, summaries of payer coverage patterns, and the clinical context that defines the service line and sites of care. The publication also highlights benchmarks and policy developments relevant to billing and reimbursement for trial-related services, and clarifies where input data is unavailable.
This executive summary provides a national perspective intended for providers, billing professionals, and policy analysts seeking clarity on coding for Phase III clinical-trial services and the implications for payer interactions and institutional billing practices.
Billing Code Overview
HCPCS Level II code S9991 represents services provided as part of a phase iii clinical trial. This code covers patient care activities and associated clinical services delivered specifically in the context of a Phase III research study.
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Service type: Clinical trial services related to Phase III research
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Typical site of service: Clinical research settings, hospital outpatient departments, academic medical centers, and other facilities conducting Phase III clinical trials
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient with metastatic non–small cell lung cancer enrolls in a phase III randomized clinical trial evaluating a novel targeted therapy versus standard chemotherapy. The site is an academic medical center's oncology clinical trials unit. Initial visit includes informed consent, baseline history and physical, performance status assessment, baseline laboratory studies (CBC, CMP), radiographic imaging for disease measurement, and collection of tumor tissue and blood for translational research per the protocol. Subsequent visits follow the trial schedule: drug administration (oral or infusion), toxicity assessment, adverse event documentation, protocol-directed laboratory monitoring, and scheduled radiographic restaging. Billing uses S9991 to denote services provided as part of the phase III clinical trial; supporting encounter items (infusions, imaging, labs, pathology, and professional visits) are billed with their usual CPT/HCPCS codes and appropriate modifiers to indicate trial-related services. Typical modifiers applied reflect unusual effort, bilateral procedures, discontinued services, or services related to research participation. Typical sites of service include hospital outpatient departments, infusion centers, and ambulatory clinical research units. Typical patient scenario includes repeated protocol-driven visits with coordinated multidisciplinary care from medical oncology, research nursing, clinical trials coordinators, and clinical research pharmacists.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 |