HCPCS C9137: Recombinant Pegylated Factor VIII Injection, per 1 i.u.

HCPCS Level II code C9137 denotes the injection of recombinant, pegylated factor VIII (antihemophilic factor), billed per 1 international unit. This code captures administration of a long-acting hemophilia A replacement therapy used for bleed prevention and treatment. Nationally, accurate use of C9137 matters for specialty pharmacy billing, medical benefit management, and payer coverage determinations due to the high cost and dosing variability of recombinant clotting factors.

Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context, typical sites of service (infusion centers, hospital outpatient departments, ambulatory clinics), and the primary reasons this code is tracked: billing specificity for per-unit dosing, alignment with medical benefit policies, and implications for utilization management.

The publication provides benchmarks for code use, summaries of relevant policy considerations and prior authorization trends, and clinical context on factor VIII pegylated products and their dosing per international unit. Where input data is unavailable, the text notes that information is not provided. The goal is to inform coding, billing, and payer policy stakeholders about the operational and clinical dimensions tied to HCPCS Level II code C9137.

Billing Code Overview

HCPCS Level II code C9137 describes an injection of factor VIII (antihemophilic factor), recombinant, pegylated, measured per 1 international unit (i.u.). The service represents administration of a long-acting recombinant clotting factor product used to treat or prevent bleeding in people with hemophilia A.

Service type: Therapeutic infusion/injection of a recombinant coagulation factor.
Typical site of service: Infusion center, hospital outpatient department, or ambulatory clinic capable of handling intravenous or subcutaneous biologic infusions.

Clinical Context

A typical patient is a male or female with hemophilia A or an acquired factor VIII deficiency requiring prophylaxis or treatment of bleeding. The patient presents to an infusion clinic, outpatient infusion center, or hospital outpatient department for intravenous administration of C9137 (injection, factor VIII, recombinant, pegylated, 1 i.u.). The clinical workflow includes verification of diagnosis and weight-based dosing, review of prior factor usage and inhibitor status, premixing and preparation under sterile conditions by pharmacy or an infusion nurse, baseline vital signs and venous access assessment, IV infusion or bolus administration per product directions, monitoring for infusion reactions during and after administration, documentation of lot number and units administered, and scheduling follow-up doses or monitoring of factor activity levels if indicated. Typical sites of service are infusion centers, hospital outpatient departments, and home infusion under supervision by a home health or specialty infusion provider. Payors commonly involved include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA, and Medicare.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	When separately reporting the professional component of a related pharmacologic service (rare for drug administration; typically not used for single-drug billing)

Taxonomy Code	Specialty	Notes
`207RH0000X`	Hematology	Specialists who manage hemophilia patients and prescribe factor replacement
`163W00000X`	Pediatric Hematology-Oncology	Pediatric specialists who manage congenital hemophilia in children
`332B00000X`	Infusion Therapy	Providers and facilities focused on administering infusion therapies in outpatient settings
`363L00000X`	Pharmacy	Specialty pharmacists who compound and dispense recombinant factor products
`261QM1800X`	Home Health Care	Home infusion providers who administer or supervise home-based factor infusions

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`D66`	Hereditary factor VIII deficiency (hemophilia A)	Primary congenital indication for replacement with recombinant factor VIII products such as `C9137`
`D68.4`	Acquired coagulation factor VIII inhibitor	Patients with inhibitors may receive specialized factor VIII products or dosing strategies; monitoring and specialist involvement required
`D68.9`	Coagulation defect, unspecified	Used when a specific coagulation disorder is present but not fully specified; may be proximate reason for factor VIII therapy
`Z79.01`	Long term (current) use of anticoagulants	While not an indication for factor VIII, this code may appear in medication history and affect management; document concurrently when applicable
`T88.6XXA`	Anaphylactic reaction due to adverse effect of correct drug or medicament, initial encounter	Relevant as a potential, though rare, adverse reaction to factor products; supports monitoring and emergency preparedness

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`96365`	Intravenous infusion, for therapy, prophylaxis, or diagnosis; initial, up to 1 hour	May be used to report administration time-based infusion services when `C9137` is administered as an infusion lasting up to 1 hour in outpatient settings
`96366`	Intravenous infusion, each additional hour (list separately in addition to code for primary infusion)	Used when infusion of `C9137` extends beyond the first hour and time-based infusion billing is appropriate
`96372`	Therapeutic, prophylactic, or diagnostic injection (specify substance or drug); subcutaneous or intramuscular	Occasionally used for non-intravenous routes if applicable to co-administered supportive medications, not for IV factor administration itself
`36415`	Collection of venous blood by venipuncture	Performed for baseline labs, factor activity levels, or inhibitor testing before or after administration of `C9137`
`96374`	Therapeutic, prophylactic, or diagnostic injection; each additional sequential intravenous push of a new substance/drug	Used when multiple distinct IV push medications are administered during the same encounter in addition to `C9137`

OpenPayer

Summary & Overview