Summary & Overview
HCPCS Q5146: Trastuzumab-strf (Hercessi) Injection, 10 mg
HCPCS Level II code Q5146 designates the biosimilar injection of trastuzumab-strf (Hercessi), supplied in a 10 mg unit. As a biosimilar to trastuzumab, this product is used in the management of HER2-positive malignancies and is billed under HCPCS Level II for drug administration and inventory reporting. Nationally, accurate coding for biosimilar oncologic agents affects claims processing, payer policy application, and aggregation of utilization data across outpatient infusion settings.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides readers with benchmarking context, common payer coverage considerations, and clinical setting implications relevant to billing and reimbursement for biosimilar trastuzumab products.
Readers will learn how HCPCS Level II code Q5146 is used to represent a 10 mg injectable unit of trastuzumab-strf (Hercessi), the typical sites of service where it is administered, and which national payers are commonly involved in coverage decisions. The summary also outlines the types of benchmarks and policy updates covered in the full publication, plus clinical context for use of biosimilar trastuzumab in HER2-positive cancer care. Data not available in the input for associated taxonomies, ICD-10 diagnoses, and related service-line specifics are noted where applicable.
Billing Code Overview
HCPCS Level II code Q5146 represents an injection formulation of trastuzumab-strf (Hercessi), biosimilar, 10 mg. This code denotes a biologic oncology medication administered via injection for indications consistent with trastuzumab therapy, typically targeting HER2-positive cancers.
Service Type: Injection, biosimilar monoclonal antibody therapy
Typical Site of Service: Outpatient infusion center or hospital outpatient department
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult with HER2-positive breast cancer receiving intravenous biosimilar trastuzumab therapy in an outpatient infusion center or hospital outpatient department. A common scenario: a patient with early-stage HER2-positive invasive ductal carcinoma receives an initial loading dose followed by maintenance dosing every 3 weeks (or weekly per protocol) administered by an oncology infusion nurse under the supervision of a medical oncologist. Pre-infusion assessment includes vital signs, review of cardiac history and recent left ventricular ejection fraction (LVEF) assessment, verification of therapy orders, and review for hypersensitivity risk. The pharmacy prepares Q5146 as a 10 mg vial of trastuzumab‑strf (Hercessi) biosimilar; dosing is calculated by body weight (mg/kg) or fixed protocol, documented in the medical record, and the administered volume and vial usage are recorded for billing, including any wastage handled per payor policies. Infusion-related monitoring includes observation for infusion reactions, cardiac monitoring when indicated, and documentation of adverse events and concurrent chemotherapy agents. Typical sites of service are outpatient infusion centers, physician offices with infusion capability, and hospital outpatient departments.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
JW | Drug discarded/not administered to any patient | Use when some drug from an opened vial is discarded and payor requires reporting of discarded biologic for unit-based billing. |