Allergy & Immunology Billing Services That Get the Units Right

Allergy and immunology billing is unlike any other specialty in one crucial respect: more than anywhere else in medicine, it lives or dies on unit counts. Percutaneous testing is billed per test, immunotherapy preparation is billed per vial or dose, and the rules governing those counts — especially the immunotherapy code 95165 — are among the most commonly miscounted, and under-billed, in all of healthcare.

The under-billing is the quiet crisis. Immunotherapy preparation is billed in units that correspond to the doses prepared from an antigen vial, and practices routinely bill fewer units than they’re entitled to — out of caution, out of confusion over payer-specific interpretations, or simply because the counting is tedious. Every under-counted vial is revenue the practice earned and never collected, month after month, invisibly.

Testing carries its own unit discipline. Percutaneous (scratch) and intradermal testing are billed per test performed (95004 and related), and the number of tests has to match the documentation exactly. Overstate it and you invite an audit; understate it and you lose revenue on services you provided. Serial dilution testing adds further per-payer rules that a generic scrubber has no way to apply.

On top of the unit work sits the high-cost biologic layer. Infusible and injectable biologics for severe asthma and chronic urticaria — agents like omalizumab — require prior authorization, step-therapy documentation, and precise J-code unit billing, and a denied biologic can leave the practice holding a very expensive bag.

What’s included, specifically:

• Percutaneous and intradermal testing billed per-unit, matched exactly to documentation
• Immunotherapy preparation (95165) unit counts done correctly — the specialty’s most common under-bill
• Serial dilution and provocative testing rules applied per payer
• Biologic (J-code) billing with unit accuracy and prior authorization
• Spirometry and pulmonary function test capture
• Injection administration coding coordinated with antigen preparation
• Denial and under-payment review focused on unit-count accuracy

Payer variation makes allergy billing even trickier, because the rules for immunotherapy units and serial dilutions aren’t uniform — different carriers interpret the same preparation differently, and a count that’s correct for one payer can be wrong for another. RevPath applies each payer’s specific interpretation rather than a single blanket rule, which both protects against denials and ensures the practice bills the full, defensible number of units every payer actually allows.

The transparency matters as much as the units. Because immunotherapy revenue is easy to under-bill invisibly, RevPath’s monthly reporting breaks out exactly how testing and immunotherapy are performing, so the practice can see its unit capture rather than trusting that it’s happening. For an allergy practice, watching that number stabilize at its correct level is often the clearest proof that revenue which used to slip away is finally being collected.

Consider a maintenance immunotherapy patient. Each visit involves administering doses drawn from previously prepared vials, and periodically preparing new vials — and the preparation is where the revenue concentrates. If the practice bills, say, ten preparation units when the documentation supports the full amount actually prepared, the shortfall repeats with every batch, for every patient on immunotherapy, all year. RevPath counts and bills those units to what the documentation actually supports, which for a busy allergy practice often surfaces meaningful revenue that was simply never captured — without adding a single patient.

This precision matters most for dedicated allergy and immunology specialty practices where immunotherapy is a revenue backbone. It leans on meticulous medical coding and sharp denial management tuned specifically to unit-count accuracy.

Because the errors here are subtle and systematic, correcting them tends to produce an outsized result — practices frequently recover more in the first months from fixing immunotherapy unit counts than from any other single change, on top of the 25–35% revenue growth our track record covers.

In allergy and immunology, getting the units right isn’t a detail — it’s the whole revenue model. RevPath counts them precisely, every batch, every visit.