Allergy testing billing is one of those areas where the CPT code structure looks straightforward until you start counting units.
Percutaneous skin tests bill per test, intradermal tests bill per test, and specific IgE blood tests bill per allergen — but the documentation, ordering requirements, and payer-specific quantity limits differ across all three.
A practice that bills 80 percutaneous tests without documenting the clinical rationale for testing that many allergens will see a medical necessity denial that retrospective documentation can’t fix.
In this guide, we’ll go through the CPT code families for allergy testing and immunotherapy, and where the billing rules differ from what most practices assume:
- Specific IgE (in vitro) blood test coding
- Common denial patterns and prevention controls
- Intradermal testing codes and when they’re appropriate
- Medical necessity documentation and payer quantity limits
- The unit-counting rules that produce the most billing errors
- Percutaneous (prick/scratch) testing codes and unit counting
- Immunotherapy administration and antigen preparation codes
TLDR: Billing for allergy testing
- Percutaneous testing uses CPT 95004 (up to 2025) or 95017 (2026+) — billed per test
- Intradermal testing uses CPT 95024 (sequential/incremental) or 95028 (delayed reaction)
- Specific IgE blood testing uses CPT 86003 — billed per allergen
- Most payers limit the number of tests per session without documented clinical justification
- Immunotherapy administration (95115/95117) and antigen preparation (95165) are billed separately
- Medical necessity documentation must explain why the specific panel of allergens was tested
- Quantity limits and prior authorization rules vary significantly by payer
Which CPT codes apply to percutaneous skin testing?
Percutaneous (prick/scratch) testing is the first-line method for identifying IgE-mediated allergies. The coding changed for 2026 — practices need to know both the legacy and current codes.
Legacy codes (through 2025)
| CPT code | Description |
| 95004 | Percutaneous tests (scratch, puncture, prick) with allergenic extracts, immediate type reaction — per test |
Current codes (2026+)
| CPT code | Description |
| 95017 | Percutaneous (scratch/prick) allergy skin tests, initial set — check current CPT for unit structure |
Unit counting
Each individual allergen tested counts as one unit. A panel testing 40 allergens is reported as 40 units of the applicable code. The documentation must list each allergen tested and the clinical indication for the panel.
Medical necessity
Payers don’t deny allergy testing because the codes are wrong — they deny because the documentation doesn’t justify testing that many allergens.
A patient presenting with seasonal rhinitis being tested for 80 allergens including foods, molds, and occupational exposures needs documentation explaining why each category was clinically indicated.
Which CPT codes apply to intradermal testing?
Intradermal testing involves injecting a small amount of allergen extract under the skin. It’s more sensitive than percutaneous testing and is typically used as a follow-up when percutaneous results are negative but clinical suspicion remains.
| CPT code | Description |
| 95024 | Intracutaneous (intradermal) tests, sequential and incremental — per test |
| 95028 | Intracutaneous (intradermal) tests for delayed type reactivity — per test |
When intradermal is appropriate
- Negative percutaneous test with persistent clinical suspicion
- Venom allergy testing (bee, wasp, hornet)
- Drug allergy confirmation
Documentation requirement
The note must document why percutaneous testing was insufficient and why intradermal follow-up was clinically necessary. Billing intradermal testing without prior percutaneous testing on the same allergens — or without documenting the clinical rationale for skipping prick testing — triggers denials from most payers.
How does specific IgE blood testing work?
In vitro allergen-specific IgE testing (blood test) is an alternative to skin testing — used when skin testing isn’t feasible or appropriate.
| CPT code | Description |
| 86003 | Allergen-specific IgE, quantitative or semiquantitative — per allergen |
| 86005 | Allergen-specific IgE, qualitative, multiallergen screen |
When blood testing is preferred
- Very young children
- Patients on antihistamines that can’t be discontinued
- Patients with severe anaphylaxis risk from skin testing
- Severe dermatologic conditions preventing skin testing
- Geographic or logistical barriers to in-office skin testing
Unit counting
86003 is billed per individual allergen. A panel testing 35 specific allergens is 35 units of 86003. Payer quantity limits apply — many commercial plans cap the number of allergen-specific IgE tests per session or per year without prior authorization for additional tests.
How does immunotherapy billing work?
Immunotherapy (allergy shots) is a separate service from the testing that identifies the allergens. Both the antigen preparation and the injection administration carry their own CPT codes.
Antigen preparation
| CPT code | Description |
| 95165 | Professional services for allergen immunotherapy — single or multiple antigens, per dose |
95165 covers the preparation of the antigen extract. It’s billed per dose prepared, not per injection administered.
Injection administration
| CPT code | Description |
| 95115 | Professional services for allergen immunotherapy — single injection |
| 95117 | Professional services for allergen immunotherapy — two or more injections |
Supervision requirements
Most payers require the patient to remain in the office for a monitoring period (typically 20–30 minutes) after each injection. The supervision time is not separately billable — it’s included in the administration code.
E/M on the same day
An E/M visit is separately billable on the same day as immunotherapy administration only when a significant, separately identifiable clinical service is provided. Modifier 25 applies. A routine injection visit that includes a brief symptom check doesn’t support a separate E/M.
What are the payer-specific rules that vary most?
Allergy testing is one of the service categories where payer variation produces the most billing surprises.
Quantity limits
- Medicare and most commercial plans limit the number of skin tests per session
- Limits typically range from 40 to 80 tests per session without prior authorization
- Additional tests beyond the limit require documentation of medical necessity and sometimes PA
Prior authorization
- Immunotherapy may require separate PA from the testing
- Some commercial payers require PA for allergy testing above a threshold
- Blood testing (86003) panels above a payer-defined allergen count may need PA
Coverage criteria
- Most payers require documented symptoms consistent with allergic disease
- Failed empiric treatment (antihistamines, nasal corticosteroids) before testing may be required
- Some payers require the ordering provider to have allergy or immunology training
What documentation prevents allergy testing denials?
The documentation burden for allergy testing is heavier than for most diagnostic tests because of the per-allergen billing structure.
Required elements
- Test results recorded per allergen
- Prior treatments attempted and their results
- Patient symptoms consistent with allergic disease
- Interpretation and treatment plan based on results
- Clinical indication for testing (what is the clinical question the testing will answer?)
- Specific allergens tested and the rationale for each category (environmental, food, venom, drug)
What triggers denials
- Intradermal testing without prior percutaneous testing or documented reason for skipping it
- Missing documentation of the clinical question the testing was intended to answer
- Number of allergens tested exceeds payer limits without justification
- Blood testing when skin testing was feasible and not attempted
- Testing performed without documented symptoms
What are the most common allergy billing errors?
These errors produce the highest volume of allergy testing denials.
- Using outdated CPT codes after annual updates
- Not tracking payer-specific quantity limits by plan
- Billing intradermal without documenting why percutaneous was insufficient
- Confusing antigen preparation (95165) with injection administration (95115/95117)
- Billing more units than payer limits allow without PA or documentation justification
- Billing a separate E/M on immunotherapy days without a separately identifiable service
Your allergy testing shouldn’t deny because the panel was bigger than the documentation
Allergy testing denials are almost always quantity or documentation problems — the clinical work was appropriate, but the record didn’t justify the scope of testing to the payer’s satisfaction. Fixing the documentation before submission prevents the denial.
MedHeave reviews allergy testing claims against payer-specific quantity limits and documentation requirements before they ship.
- Percutaneous-to-intradermal sequencing compliance
- Per-allergen unit counting validated against payer limits
- Immunotherapy preparation and administration code pairing
- Medical necessity documentation reviewed before submission
- Performance-based pricing (4–7% of collections) with no lock-in
Contact us if allergy testing denials are hitting your practice and your panel sizes need a documentation review.
Frequently asked questions
Here are some commonly asked questions on this topic:
Percutaneous (prick/scratch) allergy skin testing uses CPT 95004 (through 2025) or CPT 95017 (2026+), billed per individual allergen tested. A panel testing 40 allergens is reported as 40 units. Intradermal testing uses 95024 (sequential/incremental) or 95028 (delayed reaction), also per test. The code captures the testing method — the number of units reflects the number of allergens in the panel. Documentation must list each allergen tested and the clinical indication.
Allergen-specific IgE blood testing uses CPT 86003, billed per individual allergen tested. A multiallergen qualitative screen uses 86005. Blood testing is appropriate when skin testing isn’t feasible — antihistamine use, severe dermatologic conditions, very young patients, or high anaphylaxis risk. Payers frequently impose quantity limits on the number of 86003 units per session or per year. Documentation must explain why blood testing was chosen over skin testing when applicable.
Immunotherapy injection administration uses CPT 95115 (single injection) or 95117 (two or more injections). Antigen preparation uses CPT 95165, billed per dose prepared. These are separate from the testing codes — antigen preparation covers building the extract, administration covers delivering it. The monitoring period after injection (typically 20–30 minutes) is included in the administration code and is not separately billable.
Only when the physician provides a significant, separately identifiable clinical service beyond the injection. Modifier 25 is required on the E/M code. A routine injection visit with a brief symptom check does not support a separate E/M. A visit that addresses an unrelated medical problem, evaluates a new allergic symptom, or adjusts the immunotherapy protocol based on clinical findings may qualify — with documentation supporting the distinct service.
Most denials trace to quantity limits exceeded without documentation justification, intradermal testing billed without prior percutaneous testing or documented rationale, blood testing when skin testing was feasible, or missing documentation of the clinical question the testing was intended to answer. Payers apply per-session or per-year limits on the number of allergen tests covered without prior authorization. Staying within those limits — or documenting why exceeding them was clinically necessary — prevents most allergy testing denials.
