Summary & Overview
HCPCS J9204: Injection, mogamulizumab-kpkc, 1 mg
HCPCS Level II code J9204 denotes the injectable biologic mogamulizumab-kpkc, billed per 1 mg. The code captures drug product units for infusion or injection of this monoclonal antibody, used in outpatient infusion centers and hospital outpatient departments. Nationally, accurate use of this HCPCS Level II code matters for drug inventory management, reimbursement clarity, and consistent claims adjudication for high-cost oncology and specialty therapies.
Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of how J9204 is used on claims, payer coverage considerations, and typical sites of service. The publication outlines national benchmarks for utilization and allowed amounts where available, recent policy updates affecting specialty drug billing, and clinical context related to infusion-based biologic therapies.
The report is designed for billing managers, revenue cycle professionals, and policy analysts seeking clear guidance on coding practice, payer handling, and the administrative implications of administering and billing for mogamulizumab-kpkc in outpatient settings. Data not available in the input is noted where relevant.
Billing Code Overview
HCPCS Level II code J9204 represents an injection of mogamulizumab-kpkc, billed per 1 mg unit. This code is used to report administration of the specified monoclonal antibody product.
Service Type: Injectable biologic therapy
Typical Site of Service: Outpatient infusion center or hospital outpatient department
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult with relapsed or refractory mycosis fungoides or Sézary syndrome receiving systemic immunotherapy. The patient presents to an outpatient infusion center or oncology clinic for administration of J9204 (mogamulizumab-kpkc) as an intravenous infusion. Prior to each visit, the oncology nurse verifies the prescription, reviews prior infusion reactions, checks recent complete blood count and liver function tests, and confirms no active infections. On the day of service, the patient is triaged, vital signs are obtained, premedications (such as antihistamine and acetaminophen) are administered per protocol if indicated, and vascular access is established via peripheral IV or implanted port. The pharmacy prepares the weight- or dose-based J9204 product, documents lot and expiry, and delivers it to the infusion suite under chain-of-custody procedures. The infusion nurse administers the drug per institutional infusion rate guidelines while monitoring for infusion-related reactions, dermatologic events, or immune-mediated adverse effects. Post-infusion observation occurs per protocol, documentation of drug lot and amount is recorded in the medical record, and appropriate billing with J9204 plus any applicable modifiers is completed. Typical sites of service are outpatient hospital infusion centers, physician office-based infusion suites, and specialty oncology clinics.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|