Summary & Overview
HCPCS C9135: Factor IX (alprolix), Recombinant, Per I.U.
HCPCS Level II code C9135 designates Factor IX (antihemophilic factor, recombinant), alprolix, billed per international unit. This biologic therapy is central to care for patients with hemophilia B and carries significance for national spending on specialty pharmaceuticals and outpatient infusion services. Payers manage coverage and utilization through medical benefit pathways, prior authorization, and specialty pharmacy or infusion arrangements. Key payers addressed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find concise clinical context for C9135, typical sites of service, and what to expect in payer coverage patterns. The publication outlines benchmarks and policy-relevant considerations such as billing per unit dosing, site-of-service implications for reimbursement, and where authorizations commonly appear in payer workflows. It also highlights clinical implications for factor replacement therapy and administrative practices that affect coding and claims processing. Data not available in the input is noted where applicable; the focus remains on national relevance for providers, payers, and administrators handling specialty coagulation factor billing.
Billing Code Overview
HCPCS Level II code C9135 represents Factor IX (antihemophilic factor, recombinant), alprolix, per international unit (I.U.). This itemized biologic product is used for replacement therapy in patients with hemophilia B (factor IX deficiency).
-
Service type: Injectable biologic therapy for coagulation factor replacement
-
Typical site of service: Hospital outpatient departments, infusion centers, and physician offices for supervised intravenous administration
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult or pediatric male with hemophilia B (congenital Factor IX deficiency) who requires replacement therapy for prevention or control of bleeding. The patient presents to an infusion center, hospital outpatient department, or receives home infusion managed by a hematology clinic. A hematologist evaluates recent bleeding history, weight, baseline factor IX activity, and dosing history. Laboratory tests include factor IX activity level and hemoglobin/hematocrit as needed. The provider orders C9135 (Factor IX recombinant, alprolix, per IU) and calculates the dose in international units based on weight and target factor IX activity. Pharmacy/infusion staff reconstitute and prepare the product, verify dose, patient identity, and venous access. Infusion is administered intravenously with monitoring for infusion reactions and efficacy. Post-infusion, the patient is observed briefly, provided documentation of lot number and dose, and given follow-up instructions for activity restrictions and bleeding precautions. Typical sites of service include an outpatient infusion center, hospital outpatient department, or home infusion program coordinated by a specialty pharmacy.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | Use when unusually high drug preparation complexity or time is required beyond typical for factor replacement. |
| Professional component | Use if physician interpretation or oversight is billed separately from facility/infusion services.