HCPCS Level II code J1442 denotes an injectable dose of filgrastim (granulocyte colony-stimulating factor), billed per 1 microgram and excluding biosimilars. Filgrastim is widely used to prevent or treat neutropenia associated with chemotherapy, bone marrow transplantation, and other conditions that suppress bone marrow function. As a physician-administered biologic, billing for J1442 is relevant across outpatient infusion centers, physician offices, and hospital outpatient departments, affecting clinical workflows and drug spend nationally.

Major payers in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise review of what J1442 represents clinically, typical sites of service, common billing modifiers, and payer coverage considerations. The publication summarizes benchmark payment contexts, potential policy updates affecting biologic drug billing, and clinical indications tied to filgrastim use.

This analysis is intended for national audiences involved in revenue cycle, pharmacy, and clinical operations. It provides a clear reference for coding J1442, situating the code within therapeutic injection services and outpatient biologic administration.