Summary & Overview
HCPCS S9558: Home Injectable Growth Hormone Therapy, Per Diem
HCPCS Level II code S9558 represents a per diem billing code for home injectable therapy related to growth hormone that includes administrative services, professional pharmacy services, care coordination, and supplies and equipment; the actual drug and nursing visits are billed separately. This code is relevant nationally for payers managing home infusion and specialty pharmacy services for patients requiring growth hormone therapy outside traditional clinical settings. Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn how S9558 is used to capture non-drug, non-nursing components of home growth hormone therapy, how common payer coverage approaches may treat per diem administrative and pharmacy services, and what benchmarks and policy considerations affect billing and reimbursement for home injectable specialty therapies. The publication provides clinical context for the service line, outlines typical sites of service, and summarizes implications for claims processing and coordination between pharmacy, nursing, and care management. Data not available in the input for specific utilization rates, payer-specific reimbursement levels, associated taxonomies, and ICD-10 pairings are noted where applicable.
Billing Code Overview
HCPCS Level II code S9558 describes home injectable therapy for growth hormone, billed on a per diem basis. The code covers administrative services, professional pharmacy services, care coordination, and all necessary supplies and equipment associated with home administration of growth hormone. The drug product and any nursing visits are coded and billed separately.
Service Type: Home injectable therapy; pharmacy and care coordination services
Typical Site of Service: Patient's home (home health / home infusion setting)
Clinical & Coding Specifications
Clinical Context
A pediatric or adult patient with growth hormone deficiency (congenital, acquired, or idiopathic) receives home-based injectable recombinant human growth hormone therapy billed under S9558. Typical scenario: a patient with documented growth hormone deficiency is prescribed daily subcutaneous injections of growth hormone. The pharmacy or home infusion provider coordinates delivery of prefilled syringes or pens, provides patient/caregiver training on injection technique, safe handling and storage, sharps disposal, and offers routine professional pharmacy services and care coordination on a per diem basis. Clinical workflow: referral from an endocrinologist to a specialty pharmacy or home infusion supplier → prior authorization and benefit verification with the payer → shipment of medication and supplies to the patient’s home → initial home visit or remote education for training and competency validation → periodic nursing visits or telehealth check-ins (drug and nursing visits billed separately) → routine monitoring of growth parameters, IGF-1 levels, and adherence communicated back to the prescribing endocrinologist. Typical site of service: patient residence (home).
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier (use when no specific modifier applies) | Routine per diem billing without adjustments |