HCPCS Level II code Q5110 denotes the administration of filgrastim-aafi (Nivestym), a biosimilar granulocyte colony-stimulating factor dosed at 1 microgram. This code is used for billing the biologic injection that supports neutrophil recovery in patients undergoing myelosuppressive therapy and is important for oncology treatment pathways, supportive care workflows, and biosimilar adoption nationally. Key payers included in this overview are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will find a concise explanation of the clinical role of filgrastim biosimilars, typical sites of service where the product is administered, and the billing context for Q5110. The publication summarizes payer coverage patterns and benchmarks where available, highlights policy or coding updates affecting biosimilar injections, and outlines operational considerations for facilities and billing teams. Data limitations are noted where input fields were not provided. The goal is to give clinicians, revenue cycle staff, and policy stakeholders a focused reference on use and billing of filgrastim-aafi via HCPCS Level II code Q5110 at a national level.