Allergy Immunotherapy Insurance Denied? How to Appeal SCIT and SLIT Denials

Allergy immunotherapy is the only treatment for allergic disease that modifies the underlying immune response rather than just suppressing symptoms. For patients with allergic rhinitis, allergic asthma, allergic conjunctivitis, and insect venom hypersensitivity, immunotherapy can reduce symptoms, decrease medication use, and prevent progression to asthma. Despite its long clinical history and strong evidence base, insurance denials for allergy immunotherapy are common — and often preventable or reversible.

Two Types of Allergy Immunotherapy

Subcutaneous immunotherapy (SCIT) — allergy shots — involves injecting gradually increasing doses of allergen extracts under the skin over a build-up phase (typically 6–12 months of weekly injections) followed by a maintenance phase (monthly injections for 3–5 years). SCIT is the most established form of immunotherapy with the longest evidence record.

Sublingual immunotherapy (SLIT) involves placing allergen extracts under the tongue, either as drops or tablets. FDA-approved SLIT tablets are available for grass pollen (Grastek, Oralair), ragweed (Ragwitek), house dust mite (Odactra), and tree pollen (Itulazax). SLIT drops (aqueous allergen extracts given sublingually) are widely used off-label in the US and are standard of care in Europe and many other countries.

Common Denial Reasons for SCIT

"Allergy testing not performed or results not on file." Most payers require documented positive allergy testing — either skin prick testing (SPT) or specific IgE blood testing (RAST, ImmunoCAP) — before authorizing SCIT. If testing was performed but results were not submitted with the authorization request, resubmission with test results resolves this.

"Physician supervision requirements not met." SCIT carries a risk of systemic allergic reaction and requires administration in a medical setting with a 20–30 minute observation period and access to emergency medications (epinephrine). Medicare and most commercial payers require physician supervision of SCIT administration. Denials occur when shots are administered in settings that do not meet supervision criteria, or when the supervising physician is not an allergist or immunologist.

"Visit frequency exceeds plan limits." Some plans limit the number of allergy injection visits per year. During the build-up phase, injections may be given 1–2 times per week. If you exceed an annual visit limit before completing the build-up phase, document the clinical necessity of the visit frequency.

"Duration of treatment exceeds covered period." Some plans limit immunotherapy to a specified number of years (e.g., 3 years). However, the clinical evidence — including ACAAI (American College of Allergy, Asthma and Immunology) and AAAAI guidelines — supports 3–5 years of treatment for sustained benefit. If your clinical response at 3 years supports continued treatment, document this with outcome measures and request an extension.

Common Denial Reasons for SLIT

"SLIT is not covered." Many plans explicitly exclude sublingual immunotherapy or classify SLIT drops as not covered because they are administered outside a physician's office. This is particularly common for SLIT drops (off-label), less so for FDA-approved SLIT tablets.

"Experimental or investigational." For FDA-approved SLIT tablets, this denial is incorrect — these products have undergone rigorous FDA review. Cite the specific FDA approval date and product label for the relevant tablet product.

For SLIT drops (off-label), the "experimental" argument has more traction with payers, but substantial published evidence supports SLIT drops for common aeroallergens. Appeals citing systematic reviews and World Allergy Organization (WAO) SLIT position papers can be persuasive.

"Not administered under physician supervision." SLIT is designed for home administration after an initial observed dose in the office. Insurers may deny coverage for home SLIT. Document the initial supervised dose and the prescribing allergist's clinical rationale for home administration.

Allergy Testing Requirements and When to Challenge Them

Most payers require positive allergy testing before authorizing immunotherapy. This requirement is clinically appropriate — immunotherapy requires knowledge of what allergens a patient is sensitized to. The issue arises when:

• Testing was performed but results were not submitted correctly
• Testing was performed out-of-network and the insurer questions its validity
• The plan requires a specific type of testing (SPT vs. IgE blood test) not provided

If testing was performed by a board-certified allergist/immunologist using standardized testing protocols, document this in your appeal. Testing methodology (e.g., use of standardized extract concentrations) supports the validity of the results.

Duration of Treatment Appeals

Immunotherapy is a long-term treatment. The ACAAI and AAAAI recommend 3–5 years for sustained benefit and to reduce the risk of relapse after discontinuation. If your insurer limits coverage to a shorter period:

• Document your treatment response using validated symptom scores (Total Nasal Symptom Score, Rhinitis Quality of Life Questionnaire, or asthma control assessments)
• Document ongoing medication use reduction attributable to immunotherapy
• Cite ACAAI/AAAAI practice parameters supporting continued treatment for your clinical situation

Fight Back With ClaimBack

ClaimBack helps allergy patients navigate SCIT and SLIT denials with appeals that address testing requirements, supervision standards, and treatment duration criteria. Our platform generates letters your allergist can sign and submit immediately.

Start your allergy immunotherapy appeal now

Related Reading

• What Is Medical Necessity?
• How to Write an Insurance Appeal Letter
• Common Reasons Insurance Claims Are Denied