CPT codes standardize the billing and reporting of medical services in healthcare. CPT Code 95165 is used in allergy treatment for the preparation of patient-specific medication. This code identifies the professional services associated with the supervision and provision of antigens used in allergen immunotherapy. It allows providers to bill for customized extracts formulated to desensitize patients to specific environmental triggers like pollen, dust mites, or mold. The code covers the professional work and materials involved in creating the treatment serum, separate from the physical injection itself.
The Core Service Defined
CPT Code 95165 covers the laboratory work and professional oversight required to create a patient’s personalized allergy serum. This service encompasses the selection, measuring, and mixing of specific allergen extracts, which must be precisely tailored to the individual’s allergy profile and sensitivity level. The allergist or qualified healthcare professional develops the unique treatment plan that dictates the components and concentrations of the final product.
The preparation involves compounding multiple allergen components and various dilutions into vials for the build-up or maintenance phases of therapy. This process requires specialized training to maintain sterile conditions and ensure the stability and potency of the final extract. The preparation service is billed only once per batch of extract, regardless of the number of vials or dilutions created from that batch.
Understanding Unit Calculation and Frequency
Billing for CPT Code 95165 is based on the number of doses prepared, not on the number of physical vials provided to the patient. For most payers, including Medicare, a billable unit is defined as one cubic centimeter (1 cc) of antigen extract from a single multidose vial. This definition is a billing convention distinct from the actual volume of a clinical dose the patient receives during an injection.
When preparing a multidose vial, providers typically bill a maximum of ten units per vial. If a patient requires two separate multidose vials—one for tree pollen and one for dust mites—and each is prepared to hold ten anticipated doses, the provider reports a total of 20 units of 95165. The number of units billed must reflect the anticipated doses at the time the extract is prepared and should not be changed later. This preparation service is billed on the date the extracts are mixed, not on the date the patient receives an injection. Many insurance plans impose annual limits on the number of units that can be billed, often ranging from 120 to 250 doses per calendar year.
Differentiation from Administration Services
CPT Code 95165 covers the provision and professional supervision of the extract preparation, but not the physical act of administering the injection. Administration is a distinct professional service reported with separate CPT codes. CPT Code 95115 is used for a single injection of allergen immunotherapy.
If a patient receives two or more separate injections on the same day (e.g., one in each arm from different vials), CPT Code 95117 is reported. These administration codes cover the professional time and supplies involved in delivering the shot, including patient assessment, monitoring for reactions, and the physical injection itself. Preparation (95165) is typically billed only a few times a year when a new batch of serum is formulated, while administration (95115 or 95117) is billed every time the patient comes in for an injection appointment.
This separation is necessary because preparation and administration services are often performed by different entities or on different dates. For instance, an allergist’s office might prepare the serum, and the patient might receive injections at their primary care physician’s office. The preparation service is the upstream laboratory work, and administration is the downstream clinical delivery.
Required Documentation and Compliance
Accurate documentation is necessary to justify the use of CPT Code 95165 and ensure compliance with payer guidelines. The medical record must identify the physician who established the initial allergy treatment plan, confirming the medical necessity of the immunotherapy. Providers must maintain a detailed mixing log that specifies the exact components, concentrations, and total volume of the allergenic extract prepared.
This documentation must include the date the antigens were mixed and the total number of doses anticipated and billed. Clinical notes detailing the patient’s symptoms and diagnosis are required to support the need for the specific allergens included in the serum. Preparation must be performed under the direct supervision of a physician, meaning the physician must be present in the office suite and immediately available to provide assistance.