HCPCS Level II code Q5108 identifies injection of pegfilgrastim-jmdb (Fulphila), a biosimilar of pegfilgrastim, at a 0.5 mg dosage. This code matters nationally as pegfilgrastim and its biosimilars are commonly used to reduce the incidence of infection in patients receiving myelosuppressive chemotherapy, making accurate coding essential for clinical documentation, payment integrity, and biosimilar adoption monitoring. Key payers typically in scope for coverage and reimbursement include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will learn the clinical context for use of Q5108, typical places where the service is delivered, and the elements that influence billing and coverage determinations. The publication reviews common billing practices and benchmarks for biosimilar pegfilgrastim injections, summarizes relevant policy considerations that affect payer processing and prior authorization, and outlines coding nuances important for claims submission. Data limitations are noted where input fields are not provided. This overview is intended for national audiences including billing professionals, clinicians, and policy analysts seeking concise guidance on the use and administrative implications of HCPCS Level II code Q5108.