Summary & Overview
HCPCS C9139: Factor IX (Idelvion) Injection, 1 I.U.
HCPCS Level II code C9139 identifies the recombinant albumin-fusion factor IX product idelvion, billed per international unit. This biologic therapy is used for replacement therapy in individuals with hemophilia B to prevent or control bleeding episodes and for perioperative management. Nationally, high-cost specialty biologics such as idelvion are significant drivers of specialty pharmacy and infusion service utilization and have implications for payer coverage policies, site-of-care decisions, and prior authorization workflows.
Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context and typical settings for administration, expected billing parameters, and an outline of what benchmarking and policy topics are relevant for this code. The publication covers reimbursement benchmarks where available, common coverage and utilization management themes for high-cost coagulation factor products, and clinical considerations that affect coding and site-of-service selection. Data not available in the input is clearly noted where applicable.
Billing Code Overview
HCPCS Level II code C9139 describes the administration of injection, factor IX, albumin fusion protein (recombinant), idelvion, 1 i.u. This code represents a specific recombinant coagulation factor product used to treat or prevent bleeding in patients with hemophilia B by replacing deficient factor IX activity.
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Service type: Therapeutic intravenous or subcutaneous biologic infusion/injection
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Typical site of service: Hospital outpatient infusion center, ambulatory infusion clinic, or physician office
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult or pediatric individual with hemophilia B (congenital factor IX deficiency) who requires prophylactic or on-demand replacement therapy with a recombinant factor IX albumin fusion protein, billed as C9139 per international unit. The clinical workflow begins with a hematology assessment confirming factor IX deficiency severity and bleeding history, selection of C9139 (idelvion) for dosing based on body weight and target trough levels, and ordering by the treating hematologist or infusion specialist. Prior authorization is frequently obtained from the patient’s payer (for example, Aetna, Blue Cross Blue Shield, Cigna, UnitedHealthcare, BUCA, Medicare). The patient presents to an outpatient infusion center, hospital outpatient department, or at-home infusion program staffed by registered nurses trained in hemophilia care. Before administration, vitals and baseline assessment are completed, product reconstitution and dose calculation are verified by two clinicians per facility policy, and the intravenous infusion is delivered with monitoring for allergic reaction, thrombosis, and clinical response. Documentation includes product name C9139, units administered, lot number, expiration date, infusion site, start/stop times, and any adverse events. Follow-up appointments with the hematology team are scheduled to assess bleeding control and adjust future dosing.
Coding Specifications
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