Allergy testing and immunotherapy: where the units go wrong
Allergy and immunology is a unit-driven specialty, and that is where the revenue leaks. Percutaneous and intracutaneous testing are billed by the number of separate tests performed, patch testing by the number of patches, and antigen preparation by the number of doses prepared — not by the encounter. A practice that reports one unit for a fifty-test panel, or that miscounts vials against doses, loses money on every single visit without ever seeing a denial.
Immunotherapy adds a second layer, because the injection service and the antigen preparation are paid separately and follow different rules depending on whether one injection or multiple injections are given. When a physician supplies and prepares the extract as well as administering it, both components belong on the claim; when the extract came from elsewhere, only the administration does. We audit the vial and dose math against the schedule so the billed units match what was actually prepared and given.
Coding and documentation focus
- ✓Test counts as billed units — Percutaneous, intracutaneous, and patch testing are all reported per test or per patch, so the count in the note drives the claim.
- ✓Antigen preparation per dose — Preparation is billed by doses prepared from the vial, which requires the dose schedule to be documented, not just the vial volume.
- ✓Single versus multiple injections — The administration code differs when two or more injections are given on the same date, and the two are not stacked.
- ✓Office visit alongside testing — A visit billed on a testing or injection day needs a separately documented reason and the appropriate modifier.
Denials we prevent on these claims
- ✓One unit reported for a multi-test panel — our pre-bill audit reconciles test counts to units.
- ✓Dose counts that do not match the prepared vial — verified against the immunotherapy schedule.
- ✓Administration billed when the practice did not supply the extract — routed to the correct single component.
- ✓Same-day visit denied as bundled into the injection — corrected with documented, separate intent.
Frequently asked questions
How should allergy testing units be counted?
By the number of individual tests, not by the session. If forty skin tests are placed, forty units are supported, provided the note lists the antigens tested. The same logic applies to patch testing, which is billed by the number of patches applied.
Can antigen preparation and the injection both be billed?
Yes, when your practice both prepares and supplies the extract and administers it, the preparation and the administration are separate payable services. If the extract was supplied by another provider, only the administration is billable by you.