Allergy and immunology billing is uniquely difficult because allergen immunotherapy involves a two-part billing model: allergy serum preparation (95165) billed separately from the injection administration (95115, 95117), and most practices systematically underbill one or both components. Add to that the complexity of biologics for severe asthma and chronic urticaria (Xolair, Dupixent, Fasenra), which require prior authorization, step therapy documentation, and J-code billing, and a single coding gap can compound across an entire panel of immunotherapy patients.
Allergy and immunology medical billing demands proficiency in the two-part immunotherapy billing model, serum preparation (95165) and injection administration (95115, 95117), along with skin testing (95004), patch testing (95044), spirometry (94010), and biologic prior authorization and J-code billing (J2357, J0222, J2182). Errors in splitting immunotherapy components or a missed prior authorization can compound across an entire panel of immunotherapy patients and can prompt coding audits. Drawing on our track record in allergy and immunology billing, we provide coding education, timely billing updates, and expertise in recovering previously denied claims.
Billed Right has provided allergy and immunology billing support since 2006, serving practices across the US from our base in Longwood, Florida.
Common Pain Areas
- Allergen immunotherapy underbilling, splitting serum preparation vs. injection administration incorrectly, can quietly compound into significant lost revenue.
- Biologic prior authorization denials for severe asthma and chronic urticaria can stall treatment and delay reimbursement.
- Patch testing billing complexity can leave reimbursable units unbilled without clear per-patch documentation.
- Skin testing bundling errors can result in a same-day E/M visit being denied as included in the testing.
- Spirometry billing documentation gaps can turn a correctly performed test into an undocumented, denied service.
Allergy & Immunology Solutions
- Quick turnaround time in Denial management and follow up to appeal any denied immunotherapy or biologic infusion claims. Once the alert is activated, we will follow up within 24-48 hours and appeal any denied claims within the same timeframe.
- Key Performance Indicators (KPI) to demonstrate if your practice is achieving key business objectives.
- We work with all major EMR (electronic medical records)
- Remote login for easy access.
- Quick and smooth transition.
- No negative impact on your daily operation.
- Bilingual representatives are available.
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Top Denial Reasons
Serum Preparation Not Billed Separately from Administration
Billing only the injection administration (95115/95117) without the serum preparation (95165), or vice versa, leaves reimbursable revenue on the table on every immunotherapy visit.
Biologic Prior Authorization Missing or Expired
Xolair, Dupixent, and similar biologics require authorization renewed on a set schedule, and an expired authorization is an easy, avoidable denial.
Skin Testing Codes Bundled with E/M Visit
Skin testing billed alongside an E/M visit without modifier 25 gets the E/M line denied as included in the testing.
Patch Testing Documentation Insufficient
The number of patch testing units billed has to be clearly supported by documentation of exactly how many allergens were tested and read.
Spirometry Interpretation Not Documented Separately
Spirometry (94010) requires a documented interpretation distinct from the raw test results, and missing it is treated as an undocumented service.
Payer-Specific Considerations
Medicare covers allergen immunotherapy under Part B but has specific rules on how serum preparation (95165) and injection administration (95115, 95117) must be billed separately, and billing them as a single combined service is a routine, avoidable denial. Medicare covers biologics for severe asthma, omalizumab (Xolair, J2357), mepolizumab (Nucala, J2182), benralizumab (Fasenra), and dupilumab (Dupixent, J0222), under Part B when administered in office, but requires prior authorization and step therapy documentation showing failure of inhaled corticosteroids. Commercial payers apply strict prior authorization for all biologics with step therapy requirements that vary by plan, so the same drug can require a different documentation packet from payer to payer.
What to Expect
Billing Review
We audit recent immunotherapy, biologic infusion, skin testing, and patch testing claims and show you exactly where revenue is leaking.
Onboarding & EHR Setup
Payer setup and integration with your existing EHR/PM system, no rip-and-replace.
Credentialing Check
We verify provider enrollment status and handle re-credentialing if needed.
Claims Submission Begins
Correctly coded claims go out under full account management, same business day.
Denial Monitoring & Appeals
Denials are flagged and appealed within 24–48 hours of the alert.
Monthly Reporting
KPI dashboards show collections, A/R days, and denial trends every month.
Results Reflected in Our KPIs
Our medical billing solutions handle claim processing and follow-up on rejections so fewer claims fall through the cracks. Our allergy and immunology billing expertise helps you reduce denials and run a tighter revenue cycle.
Frequently Asked Questions
Serum preparation (95165) is billed per dose prepared, separately from the injection administration codes (95115 for a single injection, 95117 for two or more), and most practices systematically underbill one or the other. Both components have to be documented and billed on their own line to capture full reimbursement for a single immunotherapy visit.
Yes, nearly always. Xolair, Nucala, Fasenra, and Dupixent all require documented step therapy failure of inhaled corticosteroids and prior authorization before the first dose, and most payers require periodic reauthorization. Missing or expired authorization is the leading cause of biologic denials we see in allergy practices.
Percutaneous skin tests (95004) are billed per test, and the number of units billed has to match the documented number of allergens tested. Skin testing performed on the same day as an E/M visit needs modifier 25 on the E/M code, or the payer bundles the visit into the testing and denies it separately.
Patch tests (95044) are billed per patch applied, and the number of units billed has to be clearly supported by documentation of exactly how many allergens were tested and read. Insufficient documentation of the number of patches applied and interpreted is a common, avoidable denial.
Spirometry (94010) includes both the test itself and its interpretation, and the interpretation has to be documented separately from the raw test results to support the code billed. A spirometry claim without a documented interpretation is treated the same as an undocumented service.
Yes, when the biologic is administered in the office, Medicare Part B covers omalizumab (Xolair, J2357), dupilumab (Dupixent, J0222), and mepolizumab (Nucala, J2182) using the appropriate J-code, but still requires prior authorization and documented step therapy failure of inhaled corticosteroids before covering the drug.
More on allergy and immunology billing.
Allergy Coding Updates for 2026: Immunotherapy and Biologic Changes
A rundown of the immunotherapy billing and biologic prior authorization changes allergy practices need to know about this year.
ReadAllergy Immunotherapy Billing Checklist
A quick self-audit checklist for serum preparation vs. injection administration billing and biologic prior authorization before you submit a claim.
Get itAllergy Practice Fixes Immunotherapy Billing and Recovers Lost Revenue
A composite look at how a multi-provider allergy practice corrected immunotherapy and biologic documentation gaps to recover lost revenue.
ReadReady to Strengthen Your Allergy Practice Revenue Cycle?
Schedule a conversation with our allergy billing team. We will review your current claims, identify where revenue is slipping, and show you exactly what we would do differently.