Summary & Overview
HCPCS S9500: Home Infusion Antimicrobial Therapy, Per Diem
HCPCS Level II code S9500 represents a per diem administrative and professional service for home infusion antimicrobial therapy provided once every 24 hours. It captures non-drug components of at-home systemic antibiotic, antiviral, or antifungal treatment — specifically administrative coordination, professional pharmacy services, care coordination, and necessary supplies and equipment. Drugs and nursing visits for the infusion are billed separately, making S9500 a key code for separating clinical supply and oversight costs from medication and hands-on nursing fees.
This code matters nationally as home infusion grows as an alternative to inpatient care for selected infectious indications, enabling care continuity and potential cost efficiencies while requiring clear billing distinctions between services. Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.
Readers will learn what S9500 covers clinically and administratively, which services are excluded (drugs and nursing visits), and how the code fits into home infusion service lines. The publication also summarizes common modifiers, payer coverage considerations, and benchmark and policy contexts relevant to home infusion per diem billing. Data not available in the input for specific taxonomies, ICD-10 pairings, and payer-specific reimbursement rates are noted where applicable.
Billing Code Overview
HCPCS Level II code S9500 describes a home infusion therapy per diem administrative and professional service for systemic antimicrobial treatment. The code covers administrative services, professional pharmacy services, care coordination, and all necessary supplies and equipment associated with once-every-24-hours antibiotic, antiviral, or antifungal therapy. Drugs and nursing visits are billed separately and are not included in this per diem service.
Service type: Home infusion therapy — per diem administrative and professional pharmacy services
Typical site of service: Patient's home or other outpatient residence where home infusion therapy is administered
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient with a recent diagnosis of complicated cellulitis and bacteremia is discharged from the hospital but requires ongoing intravenous antibiotic therapy at home. The home infusion provider establishes a plan of care that includes daily administrative oversight, professional pharmacy services (drug preparation, stability review, and medication counseling), care coordination with the referring physician and home health nursing agency, and provision of necessary disposables and equipment. The antimicrobial drug itself and nursing visits for IV administration are billed separately. Typical workflow: physician orders home infusion; pharmacy verifies order, prepares and dispenses medication; infusion company coordinates durable medical equipment delivery (infusion pumps, IV tubing), schedules nursing visits for line access and administration, and conducts daily administrative monitoring and documentation under a per diem arrangement using the home infusion therapy code S9500 for once-every-24-hour services.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing separates professional pharmacy services from technical/supply components if applicable to payer rules. |