Allergen Immunotherapy Billing

A step-by-step guide to compliant billing for allergen vial preparation (CPT 95144-95165) in a non-profit healthcare system.

Step 1: Billing on Patient's Date of Absence

It is compliant practice to bill for preparing allergen vials on the date the mixing is completed, even if the patient isn't present.

Rationale: These CPT codes represent the professional service of preparation, which is distinct from the injection service.

Official Guidance

  • Novitas Solutions (Medicare Contractor): Confirms antigen preparation is a billable service on its own, with the date of service being the day the preparation is rendered. Read More
  • AAAAI / ACAAI: A joint statement distinguishing CPT 95165 (preparation) from injection codes, supporting it as a distinct service. Read More

Step 2: Professional (PB) vs. Hospital (HB) Charges

Billing both professional (PB) and hospital (HB) charges depends on your clinic's designation and payer policies.

Professional (PB): Covers the physician’s cognitive work (e.g., determining the formula).

Hospital (HB): Covers overhead like facility use, equipment, and non-physician staff time.

Official Guidance

  • CMS Claims Processing Manual: Details that for a hospital outpatient department, the physician's service can be billed separately from the hospital's resources. Read More (See Page 101)
  • CGS Administrators (Medicare Contractor): In a hospital outpatient setting (POS 19 or 22), the professional service can be billed alongside a facility claim. Read More

Step 3: Assigning Servicing & Billing Providers

Servicing Provider: The physician or qualified healthcare professional who supervises the vial preparation.

Billing Provider: The healthcare system or hospital entity submitting the claim under its group NPI.

Official Guidance

  • Novitas Solutions (Medicare Contractor): Links payment to services "incident to a physician's professional service," making the supervising physician the correct servicing provider. Read More

Step 4: Critical Documentation Requirements

Comprehensive documentation is essential to support medical necessity and billing. Key elements include:

  • A Physician's Signed Order
  • Detailed Allergen Formulation
  • A Mixing Log (dates, lots, preparer)
  • Proof of Medical Necessity
  • Record of Doses Prepared

Official Guidance

  • Novitas Solutions (Medicare Contractor): Their policy requires the medical record to include the diagnosis, plan of care, and antigen levels. Read More
  • AAAAI / ACAAI Joint Guidance: Details what payors expect, including a signed order, ingredient list, and preparer's initials. Read More