Allergy and immunology groups routinely deliver complex care in a single encounter: E/M, diagnostic testing, immunotherapy preparation and administration, and sometimes telehealth follow up. When the billing is not as precise as the medicine, payers respond with denials, downcodes, and post‑payment audits.
Most leaders in these practices are not struggling because they lack effort. The real issue is that allergy and immunology billing sits at the intersection of high-volume testing, longitudinal therapy, and strict medical necessity rules. If your team does not connect CPT, ICD‑10, and modifiers in exactly the way payers expect, legitimate revenue quietly disappears.
This guide walks through a practical, operations-focused approach to allergy and immunology billing. It focuses on how to structure coding and documentation around real workflows, reduce denials, and build a revenue cycle that can scale with patient demand.
1. Start With the Allergy & Immunology Billing “Stack”: E/M, Testing, Therapy
Allergy encounters are rarely single-code visits. A typical new patient might receive an evaluation and management (E/M) service, targeted history, skin testing, and a treatment discussion. Established patients may receive immunotherapy injections, observation, and asthma or rhinitis management in one session. Treat this as an integrated billing stack, not a collection of unrelated codes.
For most practices, that stack includes:
- E/M services: 99202–99215 for new and established patient visits, often driven by medical decision making around asthma control, rhinitis, immunodeficiency, or food allergy risk.
- Allergy testing codes: 95004–95078 for skin prick, intradermal, patch, and challenge testing, or 86003/86005 for serum IgE testing when skin testing is not appropriate.
- Immunotherapy codes: 95115–95117 for administration, and 95120–95199 series for preparation and supply of allergen extracts.
Why this matters: each category is governed by different policies. Payers apply separate edits to E/M, to diagnostic testing, and to immunotherapy. If your internal workflows treat “the visit” as a single item instead of a structured stack, coders may miss billable components or trip payer edits that assume services were bundled.
Operational framework for leaders:
- Define standard visit types such as “New allergy workup with testing” or “Maintenance immunotherapy visit with asthma management.” For each, build a standard set of candidate CPT codes and documentation prompts.
- Embed the stack into your EHR templates. For example, a new allergy workup template should prompt for testing indications, number of allergens, and counseling time so coders do not guess later.
- Map each visit type to expected revenue per visit. When you see large variation for the same visit type, you have a billing and documentation problem, not simply case mix.
Executives should review these visit types monthly. If an expected stack (for example E/M plus testing) routinely appears as E/M only, that indicates a charge capture or coding gap that is suppressing reimbursement.
2. Use ICD‑10 To Prove Medical Necessity, Not Just Describe the Allergy
Allergy billing often fails at the diagnosis level, not at the CPT level. Payers use ICD‑10 to decide whether the testing volume, type of immunotherapy, or number of injections is medically reasonable. If the ICD‑10 does not tell the full story, the claim looks unnecessary and gets denied or downcoded.
Commonly used codes in this space include:
- J30.1 (allergic rhinitis due to pollen) and related rhinitis codes for seasonal and perennial symptoms.
- J45.909 (unspecified asthma, uncomplicated) or more specific asthma codes that reflect severity and control status.
- T78.1XXA (other adverse food reactions, initial encounter) when evaluating suspected food allergy episodes.
- D80.* series for immunodeficiency, such as D80.1 (nonfamilial hypogammaglobulinemia), when long-term immunology follow up is required.
The issue is not simply choosing the “right” code. The issue is aligning the diagnosis with:
- The type of testing or therapy.
- The volume (for example number of allergens tested).
- The timing (for example repeat testing or step-up immunotherapy).
Example: Billing skin prick testing (95004) for 60 aeroallergens attached only to J30.9 (unspecified allergic rhinitis) is a red flag for many payers. It suggests non-specific symptoms with an unusually broad test panel. In contrast, documenting seasonal symptoms, failure of prior therapy, and using codes such as J30.1 (pollen) plus codes for conjunctivitis or asthma better supports the testing intensity.
Practical steps for leaders:
- Build ICD‑10 “bundles” for common scenarios such as seasonal allergic rhinitis with asthma, perennial rhinitis with dust mite exposure, food-induced anaphylaxis, or chronic urticaria. Teach providers and coders to use these bundles instead of single vague codes.
- Audit the top 20 diagnosis codes quarterly. Check how often they appear with high-cost tests or immunotherapy. When you see high utilization of nonspecific codes (for example J30.9) with high-cost procedures, target provider education.
- Align documentation prompts to coverage policies. If your major commercial payer expects failure of pharmacotherapy before extensive testing, build that into the note templates and pre-visit planning.
Good ICD‑10 strategy does not just reduce denials. It also lowers audit risk by making the logic of your care plan obvious to anyone reviewing the chart months or years later.
3. Structure Allergy Testing Billing Around Volume, Method, and Policy Limits
Allergy testing is a high-revenue and high-scrutiny area. Codes like 95004, 95024, 95044, and 86003 are billed “per test” or “per allergen,” which means small documentation gaps scale into large financial risk. Payers routinely review testing claims for medical necessity, duplication, and adherence to published limits.
To manage this effectively, your billing playbook for testing should cover three dimensions:
3.1 Volume and counting logic
Each payer may interpret “per test” slightly differently. For skin prick testing (95004), most require:
- Documentation of each allergen tested.
- Clear indication of controls used.
- A total count that matches the billed units.
For intradermal testing (95024), payers often expect it to follow inconclusive or borderline prick testing, not as a first-line approach. Patch testing (95044) needs a documented panel and reading schedule. Serum IgE testing (86003) is typically limited to specific scenarios, such as severe eczema, dermatographism, or patients who cannot stop interfering medications.
3.2 Medical necessity and stepwise logic
Testing should appear as a rational escalation from history, physical examination, and prior therapy. For example:
- Initial history and examination: trial of pharmacotherapy for rhinitis.
- Persistent symptoms despite therapy: targeted prick testing based on exposure history.
- Inconclusive results and strong suspicion: intradermal testing for selected allergens.
Claims that show large, non-targeted test panels at the first visit are more likely to be denied or flagged for audit.
3.3 Payer-specific limits and frequency controls
Many payers publish limits on the total number of allergens per year or per testing episode, as well as rules on repeat testing. Operationally, you need:
- A payer policy library for allergy testing that coders and providers can access easily.
- Front-end checks in the EHR or practice management system when ordering more than a given threshold of tests for certain plans.
- Pre-service review for atypical scenarios such as very large food panels, multiple patch test series, or frequent repeat IgE panels.
From a revenue cycle perspective, your testing program should be tracked using KPIs such as:
- Denial rate specific to allergy testing CPT codes.
- Average revenue per testing encounter by payer.
- Percentage of testing claims that require appeals before payment.
If testing denials exceed 5 to 8 percent of submitted charges, it is usually a signal that policies are not fully understood by either providers or coders and that documentation is not tightly aligned with those policies.
4. Manage Immunotherapy Billing Across the Full Course of Treatment
Immunotherapy is not a single event. It is a multi-year plan with extract preparation, dose build-up, maintenance schedules, observation time, and sometimes dose adjustments after systemic reactions or missed visits. Successful billing requires a longitudinal view instead of a “visit by visit” mentality.
Key components include:
- Extract preparation and supply: Codes in the 95120–95165 range reflect preparation of single or multiple antigen vials. Some payers require documentation of antigen composition and concentration in the chart.
- Administration codes: 95115 (single injection) and 95117 (two or more injections) are tied to each session. They often cannot be billed with certain other procedures unless the encounter is clearly distinct.
- Observation and reaction management: While observation is generally included in the administration service, significant adverse reactions that require additional E/M work may justify separate billing with appropriate modifiers and documentation.
Revenue leaders should think of immunotherapy as a managed program with these controls:
- Plan-level documentation: A written immunotherapy plan that covers indications, antigen selection, concentration, schedule, and expected duration. This supports the initial extract billing and sets the context for future injections.
- Tracking missed or late injections: When a patient misses multiple injections, many protocols call for dose reduction or “backing up” on the schedule. Your documentation should show the clinical reasoning. This can be critical if a reaction occurs after a dose change and the payer reviews the chart.
- Authorization and benefit checks: Some payers require prior authorization not just for the initial extract but for continued therapy after a certain duration. A lack of process here can lead to sudden, large-volume denials for ongoing immunotherapy.
Useful immunotherapy KPIs include:
- Average paid amount per immunotherapy patient per year, by payer.
- Percentage of immunotherapy charges denied for “coverage exceeded” or “authorization required.”
- Rate of appeal success on immunotherapy denials, which reveals whether your documentation is persuasive.
Practices that monitor these metrics quarterly can intervene early, for example by tightening eligibility checks or updating templates to reflect payer-specific long-term treatment rules.
5. Use Modifiers To Separate E/M, Testing, and Procedures Without Triggering Audits
Modifiers are often the only way to tell a payer that an E/M service and diagnostic or therapeutic procedure were genuinely separate on the same day. Used correctly, they secure legitimate revenue. Used loosely, they invite denials and potential post‑payment review.
Three modifiers are particularly important in allergy and immunology billing:
- Modifier 25: Indicates a significant, separately identifiable E/M service on the same day as a procedure or other service.
- Modifier 59: Indicates a distinct procedural service that is not normally reported together with another service but is appropriate in the specific circumstance.
- Modifier 76: Indicates a repeat procedure by the same physician or qualified professional on the same day.
Operational guidance for each:
5.1 Modifier 25 on allergy visits
This modifier should appear when the physician or advanced practice provider performs a full E/M service that goes beyond the work inherent in allergy testing or immunotherapy administration. For example, a patient with poorly controlled asthma and allergic rhinitis is evaluated, medication changes are made, and skin testing is performed in the same visit. The E/M covers history, exam, and decision-making about chronic disease management. Testing is a separate service that informs that management.
To support Modifier 25:
- Ensure the note clearly separates the E/M assessment from the procedural portion.
- Avoid templated text that simply repeats the testing description as the “assessment.”
- Train providers that “taking a brief history for testing” alone is not enough for an E/M with Modifier 25.
5.2 Modifier 59 on testing combinations
Use Modifier 59 when different testing methods or anatomically distinct services are performed that would otherwise be bundled. For instance, a targeted set of prick tests followed by intradermal tests for a smaller subset of allergens with persistent suspicion. Documentation must show:
- Why the second method was required.
- How it was different in scope or technique from the first.
Without a clear narrative, payers may consider the services redundant and deny the second set of tests even with Modifier 59 attached.
5.3 Modifier 76 for repeat procedures
Occasionally, a repeat test or injection is needed on the same day for clinical reasons, such as an equivocal result that requires confirmation. Modifier 76 signals that the repeat service was intentional and medically necessary. Make sure the note specifies the reason for the repeat and the result that drove that decision.
From a revenue cycle management perspective, you should:
- Monitor usage of Modifiers 25 and 59 per provider and compare against peer benchmarks.
- Sample 10 to 20 records monthly that include these modifiers and confirm that the documentation clearly supports them.
- Address overuse quickly, because excessive use of these modifiers often attracts payer audits.
6. Build a Denial-Resistant Allergy & Immunology Billing Workflow
Isolated coding corrections will not fix systemic allergy billing issues. You need an end‑to‑end workflow that is designed with payer behavior in mind. The highest performing practices approach this as an iterative operations project, not a one-time training.
A practical, denial-resistant framework can include:
6.1 Pre-service checks
- Eligibility and benefits verification focused on testing and immunotherapy benefits, including quantity limits and authorization rules.
- Policy review for atypical orders, such as very large food panels or extensive repeat testing, before the patient ever arrives.
- Documentation prompts in scheduling notes when prior therapy failure or specific triggers must be documented to meet coverage policy.
6.2 Point-of-care documentation discipline
- Use structured fields to capture number of allergens, specific panels, test controls, and observed reactions.
- Ensure providers document the clinical question each test is answering. For instance, “Determine sensitization to perennial indoor allergens in a patient with year-round rhinitis and asthma.”
- In immunotherapy visits, record dose changes, missed injections, and rationale for any protocol deviations.
6.3 Back-office coding, scrubbing, and analytics
- Deploy billing edits that look for inconsistencies, such as high-volume testing with vague ICD‑10 codes or Modifier 25 on low-level E/M with minimal documentation.
- Track denial reasons at the code-group level: segregate testing, immunotherapy, and E/M so problem areas are visible.
- Calculate days in A/R, first-pass resolution rate, and net collection rate specifically for allergy and immunology service lines, not just at the enterprise level.
Once you have this workflow, conduct quarterly “micro‑audits” that follow a small sample of patients from scheduling through payment. Look for gaps such as undocumented medical necessity, miscounted allergens, or missing modifiers. Fix those at the process level rather than through one-off claim corrections.
7. When To Bring In External Billing Expertise
Many independent groups and hospital-owned allergy services reach a point where internal staff are overwhelmed by payer rule changes, technology demands, and audit anxiety. At that stage, leaders should honestly assess whether they have the internal depth to maintain high-performance allergy billing at scale.
Signals that external support might be warranted include:
- Persistent denial rates above 10 percent for allergy testing or immunotherapy.
- Net collection rates that lag comparable specialties even after fee schedule adjustments.
- Heavy reliance on a single senior biller whose departure would create major operational risk.
- Increased payer medical record requests or focused audits targeting allergy services.
If your organization is looking to improve billing accuracy, reduce denials, and strengthen overall revenue cycle performance, working with experienced RCM professionals can make a measurable difference. One of our trusted partners, Quest National Services, specializes in full-service medical billing and revenue cycle support for healthcare organizations navigating complex payer environments.
Whether you keep billing in‑house, partner with an external team, or pursue a hybrid model, executive ownership of allergy and immunology revenue performance remains critical. Leaders should insist on visibility into code-level trends, denial patterns, and documentation quality for this high-value service line.
Ultimately, improving your allergy and immunology billing is not just an administrative exercise. It protects your ability to offer advanced diagnostics and long-term immunotherapy programs without financial instability. If you are ready to review your own performance, start with a focused internal assessment of CPT usage, ICD‑10 alignment, and modifier patterns, then align your team around a concrete improvement plan. When you are prepared to turn that plan into measurable results, you can reach out through our contact page to explore next steps.
References
Centers for Medicare & Medicaid Services. (n.d.). Medicare coverage database: Allergy testing and immunotherapy. Retrieved from https://www.cms.gov/medicare-coverage-database/search.aspx
