Summary & Overview
CPT 95120: Allergen Immunotherapy Injection, Single Dose
CPT code 95120 represents a single allergen immunotherapy injection administered as part of a graduated series of shots intended to induce tolerance to specific allergens. This code captures the administration event when a provider gives one injection during a dosing session rather than multiple concurrent injections. Nationally, allergen immunotherapy is a common treatment for allergic rhinitis, allergic conjunctivitis, and some cases of allergic asthma, making accurate billing for individual injections important for clinical documentation and payment consistency.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of coding context, expected sites of service, and common clinical scenarios in which 95120 is used. The publication outlines typical payer considerations and common modifiers reported in practice. It also summarizes benchmarking points and recent policy clarifications where available. This resource is intended to help billing managers, revenue cycle staff, and clinicians understand when to use CPT code 95120, what settings typically report it, and what topics to review in payer policies and internal billing protocols. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 95120 describes a single injection administered as part of an allergen immunotherapy series. This procedure is used when a provider gives one injection of an allergenic extract during a session in a graduated dosing schedule designed to achieve clinical tolerance to specific allergens.
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Service type: Allergen immunotherapy injection (single administration within a series)
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Typical site of service: Outpatient clinic or office setting where allergy shots are provided, including allergy/immunology offices and primary care practices that administer immunotherapy.
Clinical & Coding Specifications
Clinical Context
A 35-year-old patient with seasonal allergic rhinitis and demonstrated sensitivity to grass and tree pollen presents to an allergy clinic for maintenance immunotherapy. Following an initial build-up phase of gradually increasing allergen extract concentrations, the patient attends routine visits every 2–4 weeks for a single subcutaneous injection of the maintenance allergenic extract. The clinical workflow includes check-in and screening for acute illness or recent systemic reactions, focused pre-injection assessment (vital signs and review of medications/anticoagulants), confirmation of the correct allergen extract and dose by the nurse or allergy clinician, administration of a single subcutaneous injection with observation in the clinic for 20–30 minutes for potential local or systemic allergic reactions, and documentation of the lot number, dose, site, and any immediate adverse events in the medical record. Billing uses 95120 for the single injection administered at the session as part of the immunotherapy series.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier | Standard reporting when no modifier is applicable |
22 |