Summary & Overview
HCPCS Level II C9173: Filgrastim-txid (Nypozi) Injection, 1 mcg
HCPCS Level II code C9173 designates the injection of filgrastim-txid (nypozi), a biosimilar granulocyte colony-stimulating factor, at a 1 microgram unit. This code matters nationally because G-CSF biosimilars are widely used to reduce infection risk from chemotherapy-induced neutropenia and to support hematopoietic recovery in multiple clinical settings; accurate coding ensures clinical documentation aligns with payer coverage and reimbursement processes.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical purpose of C9173, typical sites of service, and what to expect in payer coverage practices. The publication outlines benchmarks and coding context relevant to biosimilar filgrastim administration, highlights policy considerations for national payers, and summarizes common modifier usage and billing nuances when available.
This summary is intended for coding professionals, practice administrators, and policy analysts seeking a national perspective on how HCPCS Level II code C9173 is used for biosimilar filgrastim injections and how it fits into payer and clinical workflows. Data not available in the input is noted where applicable.
Billing Code Overview
HCPCS Level II code C9173 describes an injection of filgrastim-txid (nypozi), biosimilar, 1 microgram. This code represents administration of a biosimilar granulocyte colony-stimulating factor (G-CSF) used to stimulate neutrophil production.
Service type: therapeutic injection / biologic agent administration
Typical site of service: clinic, outpatient infusion center, or hospital outpatient department
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A 58-year-old patient with chemotherapy-induced neutropenia receives a single-dose subcutaneous injection of filgrastim‑txid (C9173, 1 microgram) in an outpatient oncology infusion clinic. The patient presents for routine post-chemotherapy supportive care after receiving cytotoxic chemotherapy for a solid tumor. The clinic nurse verifies recent absolute neutrophil count (ANC), assesses for fever or infection, documents prior dosing and lot number of the biosimilar product, obtains informed consent for supportive colony‑stimulating factor therapy, and administers the injection into the subcutaneous tissue of the abdomen or thigh. The encounter includes medication administration, patient education on injection-site care and signs of infection, and scheduling of follow-up laboratory monitoring (CBC with differential) within 24–72 hours. Billing reflects the HCPCS Level II code C9173 by units administered and may include applicable modifiers for unusual circumstances such as bilateral procedures, significant additional work, or payer-specific requirements.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | When significant additional work beyond the typical injection administration is documented (rare for single-dose injection; e.g., complex nursing interventions). |