Summary & Overview
HCPCS Level II Q0243: Injection, casirivimab and imdevimab, 2400 mg
HCPCS Level II code Q0243 denotes an injection of casirivimab and imdevimab, 2400 mg, a monoclonal antibody combination used for passive immunization. Nationally, this code is important for tracking use and payment of high-cost biologic therapies administered in outpatient infusion settings during public health responses and routine therapeutic care.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna, UnitedHealthcare, and Medicare. The coverage landscape for Q0243 has implications for provider billing, patient access to monoclonal antibody treatment, and reimbursement policy for outpatient infusion services.
Readers will find benchmarks and payment context for this HCPCS Level II code, summaries of payer coverage approaches, clinical context around the therapy type and typical sites of service, and notes on coding considerations where available. The publication highlights policy updates and payer-specific guidance when present, and it flags areas where input data were not provided. This summary is national in scope and focuses on operational and policy-relevant information for health systems, coders, and payer relations teams.
Billing Code Overview
HCPCS Level II code Q0243 represents an injection of casirivimab and imdevimab, 2400 mg. This entry describes a monoclonal antibody combination product provided as an intravenous or subcutaneous therapeutic infusion for passive immunization against certain viral infections.
Service type: Therapeutic monoclonal antibody infusion/injection
Typical site of service: Outpatient infusion center, hospital outpatient department, or clinic-based infusion setting
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical adult patient with confirmed mild-to-moderate COVID-19 who is at high risk for progression to severe disease presents to an outpatient infusion center or hospital-based infusion clinic within the early days of symptom onset. The clinical workflow involves screening for eligibility (risk factors such as age, obesity, chronic cardiopulmonary disease, immunocompromise), confirming positive SARS-CoV-2 testing, obtaining informed consent, verifying contraindications and current medications, and documenting baseline vital signs and allergy history. The medication Q0243 (Injection, casirivimab and imdevimab, 2400 mg) is prepared by pharmacy under aseptic technique, administered as an intravenous infusion over the recommended time with monitoring for infusion-related reactions, and the patient is observed post-infusion for adverse events. Documentation includes indication, lot numbers, dose administered, infusion start and stop times, consent, and any adverse reactions. Typical sites of service are outpatient infusion centers, emergency departments, and hospital-based infusion clinics. Common modifier usage for billing includes SH when the service is provided under the Public Health Emergency or similar supply source designation.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
SH | Drug or biological furnished directly by the health department, a state, local, tribal, or territorial public health agency |