HCPCS Level II code S9366 represents a per diem payment for home infusion therapy providing total parenteral nutrition (TPN) of more than one liter but no more than two liters per day. The code bundles administrative and professional pharmacy services, care coordination, and necessary supplies and equipment, and excludes separately billed drugs outside the standard formula and nursing visits. This code matters nationally as home TPN supports patients with complex nutritional needs outside inpatient settings, influences utilization of home infusion services, and affects pharmacy and care-coordination billing practices.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides a concise overview of the code's clinical context, typical site of service, and what services are bundled versus billed separately. Readers will find benchmark considerations for per diem home TPN services, common billing and coverage issues, and a summary of policy and coding details relevant for payers, providers, and pharmacy services. Data not available in the input for payer-specific rates, taxonomies, ICD-10 pairings, and related codes are noted where applicable.