Summary & Overview
HCPCS S9357: Home Infusion Enzyme Replacement Therapy Administrative Services
HCPCS Level II code S9357 represents per diem administrative and professional pharmacy services associated with home infusion enzyme replacement therapy, such as imiglucerase, with drugs and nursing visits reported separately. This code captures care coordination, supplies, and equipment required to support home-based intravenous enzyme replacement therapy, making it important for payers and providers managing complex, high-cost specialty infusions outside the acute care setting. Nationally, effective use of S9357 informs reimbursement for non-drug components of home infusion programs and affects access to in-home specialty therapies.
Key payers included in the analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn the clinical and billing context for S9357, typical site-of-service considerations, and what elements this per diem code is intended to cover. The publication summarizes benchmark considerations, payer coverage patterns where available, and policy implications for structuring home infusion benefit administration. It also highlights operational implications for pharmacies and infusion providers when drugs and nursing are billed separately from administrative per diem services. Data not available in the input is noted where relevant.
Billing Code Overview
HCPCS Level II code S9357 describes home infusion therapy for enzyme replacement intravenous therapy (for example, imiglucerase) including administrative services, professional pharmacy services, care coordination, and all necessary supplies and equipment. The code is billed on a per diem basis; drugs and nursing visits are coded separately.
Service Type: Home infusion therapy — enzyme replacement therapy administrative and coordination services
Typical Site of Service: Patient home (home infusion setting)
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult with a confirmed lysosomal storage disorder such as Gaucher disease requiring regular enzyme replacement therapy (ERT) administered intravenously at home. The patient has an established treatment plan from a hematologist or metabolic specialist and receives home infusion services ordered by the treating physician. A certified home infusion pharmacy coordinates delivery of the enzyme product (billed separately), provides professional pharmacy services, supplies infusion equipment and disposables, and arranges nursing visits for vascular access, infusion administration, and patient monitoring. Per diem administrative services include prior authorization support, care coordination with the specialty clinic, education for the patient and caregiver on infusion procedures and adverse event recognition, and documentation of each infusion encounter. Typical workflow: physician orders ERT and home infusion per diem S9357; prior authorization and benefit verification are completed; home infusion pharmacy prepares schedule and ships supplies; a licensed nurse performs pre-infusion assessment, vascular access, infusion set-up, monitors vital signs during infusion, documents the encounter, and communicates any adverse events to the physician; pharmacy manages ongoing scheduling, medication logistics, and claims submission. The typical site of service is the patient’s home or other community residence where safe infusion can occur under nursing supervision.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 |