HCPCS Level II code S0145 denotes the injection of pegylated interferon alfa-2a at a concentration of 180 mcg per ml, a biologic injectable used in antiviral and immunomodulatory treatment regimens. This code matters nationally because it identifies billing for an expensive specialty drug administered in outpatient settings, affecting coverage decisions, prior authorization processes, and reimbursement across major payers. Key payers covered in this summary include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will learn what the code represents clinically and operationally, which payers commonly process claims for this service, and the types of benchmarks and policy topics typically associated with specialty injectable drugs—such as utilization, site-of-service considerations, and payer coverage policies. The publication provides benchmarking context where available, notes common administrative considerations for billing and claims processing, and outlines policy developments that commonly impact similar HCPCS Level II drug codes. Data not available in the input is noted where specific benchmarks, taxonomies, ICD-10 pairings, and detailed payer policy variations would normally be described.