C9149 teplizumab Reimbursement & Policy

HCPCS Level II code C9149 denotes the provision of teplizumab-mzwv in 5 microgram units as an injectable biologic therapy. Teplizumab is a monoclonal antibody formulation used in targeted immunotherapy, and capturing its administration with a specific HCPCS Level II code supports accurate billing, utilization tracking, and payer coverage determinations for novel biologic agents. Nationally, precise coding for high-cost biologics affects benefit design, prior authorization workflows, and provider reimbursement processes.

Key payers considered include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides readers with benchmarks for coding and billing practices, summaries of payer coverage patterns where available, and clinical context around the service type and sites of administration. It also outlines common modifiers and administrative considerations relevant to injectable biologics.

Readers will learn: the clinical and billing definition of C9149, typical settings where teplizumab-mzwv is administered, how major payers treat coverage at a high level, and where to find related coding resources. Data not available in the input is noted where applicable.

Billing Code Overview

HCPCS Level II code C9149 represents Injection, teplizumab-mzwv, 5 mcg. This code describes a biologic injectable formulation of teplizumab-mzwv provided in 5 microgram increments. The service type is an injectable biologic therapy administered parenterally. The typical site of service is an outpatient infusion or injection setting, such as an ambulatory infusion center, specialty clinic, or physician office that administers biologic injections.

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Clinical Context

A typical patient is a 10–17-year-old with newly diagnosed stage 1 type 1 diabetes mellitus at high risk for clinical progression, presenting to an outpatient pediatric endocrinology infusion center for disease-modifying therapy. The patient arrives with a parent, has baseline vital signs, recent labs (blood glucose, HbA1c, and screening for viral infections), and confirmation of eligibility per prescribing information. The clinical workflow includes verification of identity and consent, review of prior medical history and concomitant medications, pre-infusion assessment for contraindications (active infection, immunosuppression), and preparation of the dose of C9149 (teplizumab-mzwv, 5 mcg unit). A trained infusion nurse or pharmacist administers the intravenous infusion per protocol, monitors for infusion reactions and hypoglycemia, documents start/stop times, and records lot number and NDC. Post-infusion observation occurs for a specified period with documentation of adverse events. Billing captures the HCPCS Level II code C9149 for the administered product, appropriate facility or professional components, and any applicable modifiers for unusual circumstances or payer requirements.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when work, time, or technical difficulty of administration is substantially greater than typical (requires documentation).

Taxonomy Code	Specialty	Notes
207RC0000X	Endocrinology, Pediatric	Pediatric endocrinologists prescribe and oversee teplizumab treatment protocols.
363L00000X	Hematology & Oncology	Infusion centers under these specialists may manage complex biologic infusions.
364SP0800X	Nursing — Infusion Therapy	Infusion nurses perform preparation, administration, and monitoring.
208000000X	Internal Medicine	Adult endocrinologists may manage older adolescents transitioning to adult care.
3336C0003X	Pharmacist	Clinical pharmacists compound, verify dosing, and document drug dispensing.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`E10.9`	Type 1 diabetes mellitus without complications	Common primary diagnosis for patients receiving teplizumab to delay onset or modify disease course.
`E10.21`	Type 1 diabetes mellitus with diabetic nephropathy	Relevant when comorbid kidney disease affects eligibility or monitoring.
`E10.65`	Type 1 diabetes mellitus with hyperglycemia	Active hyperglycemia may influence infusion timing and monitoring needs.
`E10.42`	Type 1 diabetes mellitus with diabetic polyneuropathy	Comorbidity affecting overall disease management during therapy.
`Z79.4`	Long term (current) use of insulin	Documented to show baseline diabetes management context in patients receiving disease-modifying therapy.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`96365`	Intravenous infusion, for therapy, prophylaxis, or diagnosis; initial, up to 1 hour	Often used to report the initial infusion time segment for intravenous biologic administration in infusion centers.
`96366`	Intravenous infusion, each additional hour	Used to bill additional hourly infusion time beyond the initial hour when administration extends longer.
`96372`	Therapeutic, prophylactic, or diagnostic injection (intramuscular); subcutaneous or intramuscular	Used when separate subcutaneous injections are given in conjunction with infusion visits (e.g., supportive meds).
`36415`	Collection of venous blood by venipuncture	Used for pre-infusion or monitoring lab draws tied to the infusion visit.
`99070`	Supplies and materials provided by the physician over and above those usually included with the office visit	Used to bill for special disposables or drug-specific supplies when permitted by payer.

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Summary & Overview

HCPCS C9149: Injection, teplizumab-mzwv, 5 mcg