Summary & Overview
HCPCS Q5112: Injection, trastuzumab-dttb (Ontruzant), 10 mg
HCPCS Level II code Q5112 denotes the 10 mg unit of trastuzumab-dttb (Ontruzant), a biosimilar therapeutic used in the treatment of HER2-positive cancers. As a biosimilar alternative to reference trastuzumab products, this code matters nationally for oncology infusion billing, payer coverage policies, and cost-management strategies across hospital outpatient and ambulatory infusion settings. Adoption of biosimilars can affect formulary decisions, site-of-care cost analyses, and prior authorization workflows.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical and billing identity of the product, the typical infusion service setting, and what to expect from payer coverage considerations at a national level. The publication outlines benchmarking points for utilization and unit-level billing, important policy updates affecting biosimilars and oncology drug reimbursement, and clinical context regarding trastuzumab biosimilar use.
This summary is intended to inform coding, billing, and policy teams about the code's purpose, common service locations, and the types of payer policies that most influence reimbursement and access for biosimilar trastuzumab products. Data not available in the input will be noted explicitly where applicable.
Billing Code Overview
HCPCS Level II code Q5112 describes an injection of trastuzumab-dttb (Ontruzant), 10 mg. This code represents a biosimilar formulation of trastuzumab, an intravenous monoclonal antibody used in oncology care for HER2-positive cancers.
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Service type: Therapeutic drug administration (parenteral oncology medication)
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Typical site of service: Outpatient hospital infusion center or ambulatory infusion clinic
Data not available in the input for associated taxonomies, ICD-10 diagnoses, and related codes.
Clinical & Coding Specifications
Clinical Context
A typical patient is a adult with HER2-positive breast cancer or a HER2-overexpressing metastatic malignancy receiving intravenous infusions of a trastuzumab biosimilar, Q5112 representing trastuzumab-dttb (Ontruzant) in 10 mg vial units. The clinical workflow begins with oncology evaluation and staging confirmation including pathology reports showing HER2 positivity. Prior to infusion, the patient undergoes baseline assessment: vitals, review of cardiac history and recent echocardiogram or MUGA scan, chemotherapy consent, and allergy screening. The medication is prepared by pharmacy in an oncology infusion suite or hospital outpatient infusion center using compounded aseptic technique; dosage is calculated based on patient weight and the prescribed regimen (loading and maintenance phases). Nursing performs IV access placement, pre-medication per protocol if needed, and monitors for infusion-related reactions during and after administration. Documentation includes medication name and NDC, lot number, amount administered (milligrams and number of vials), start and stop times, infusion rate, patient tolerance, and billing using Q5112 with appropriate modifier(s) as indicated.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier / not otherwise specified |