Summary & Overview
HCPCS M0221: Tixagevimab and Cilgavimab Pre-Exposure Prophylaxis
HCPCS Level II code M0221 represents the administration of tixagevimab and cilgavimab for pre‑exposure prophylaxis against SARS‑CoV‑2 in eligible individuals. It applies to adults and pediatric patients aged 12 years and older weighing at least 40 kg who have no known exposure and who either are moderately to severely immunocompromised or cannot receive COVID‑19 vaccination due to a history of severe adverse reaction. Nationally, this code is important for payers and providers managing access to monoclonal antibody prophylaxis in high‑risk populations and for documenting home‑based administration and monitoring.
Key payers covered in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise account of clinical context, common billing practice considerations, and the service setting — emphasizing that M0221 bundles the injectable medication with post‑administration monitoring conducted in the patient’s home or residence. The publication provides benchmarks and policy context relevant to coverage and claim submission for home‑based monoclonal antibody prophylaxis, highlights billing implications for hospital‑designated homes during the COVID‑19 public health emergency, and outlines where input data is not available. Data not available in the input will be noted where applicable.
Billing Code Overview
HCPCS Level II code M0221 covers injection of tixagevimab and cilgavimab for pre-exposure prophylaxis against SARS‑CoV‑2. The code applies to certain adults and pediatric individuals aged 12 years and older weighing at least 40 kg who have no known SARS‑CoV‑2 exposure and who either have moderate to severely compromised immune systems or for whom COVID‑19 vaccination is not recommended because of a history of severe adverse reaction to a COVID‑19 vaccine or vaccine component.
Service type: Medication administration with post‑administration monitoring in the home or residence. The description explicitly includes the injection and observation period provided in a beneficiary’s home, including homes that were made provider‑based to a hospital during the COVID‑19 public health emergency.
Typical site of service: Home or residence (including home designated provider‑based to a hospital during the COVID‑19 public health emergency).
Data not available in the input for associated taxonomies, specific ICD‑10 diagnoses, and related codes.
Clinical & Coding Specifications
Clinical Context
A 58-year-old patient with a history of renal transplant on chronic immunosuppressive therapy is scheduled to receive pre-exposure prophylaxis with tixagevimab and cilgavimab at home. The patient has no known SARS-CoV-2 exposure and is not a candidate for COVID-19 vaccination due to a prior anaphylactic reaction to a vaccine component. A home health nurse performs pre-visit screening for active COVID-19 symptoms, verifies patient identity and informed consent, confirms weight ≥ 40 kg and age ≥ 12 years, and reviews relevant allergies and current medications. The nurse reconstitutes and prepares the intramuscular injections, administers the doses per manufacturer guidance, monitors the patient on site for the required post-administration observation period, documents lot numbers and injections in the medical record, and communicates administration details to the patient’s transplant clinic. Billing occurs using M0221 with appropriate modifier(s) to indicate site of service or circumstances (for example, home administration or provider-based status). Typical documentation includes indication (immunocompromised state or vaccine contraindication), consent, medication dosing and lot numbers, observation time, and any adverse events.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
AS | Physician assistant, nurse practitioner, or clinical nurse specialist services furnished in part-time, intermittent, or other settings under a supervising physician |