Summary & Overview
CPT 86510: Histoplasma capsulatum Skin Antigen Test
CPT code 86510 represents a diagnostic skin antigen test for Histoplasma capsulatum in which a laboratory analyst reads and interprets the patient’s response to an intradermal antigen injection. Nationally, the test is relevant for assessing prior exposure to histoplasmosis and for certain clinical and epidemiologic evaluations of fungal sensitization. Coverage and utilization can affect public health surveillance and specialty infectious disease workflows.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The document outlines payer coverage patterns, typical sites of service, and coding context for clinicians and billing staff.
Readers will find clinical context on when the Histoplasma skin antigen test is used, operational details such as typical laboratory and outpatient clinic settings, and benchmarks or policy considerations that influence billing and coverage. Where available, the analysis summarizes reimbursement benchmarks, common billing practices, and implications for coding accuracy. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 86510 describes a laboratory procedure in which the lab analyst evaluates a patient's immunologic response to a skin injection of antigens derived from the fungus Histoplasma capsulatum. This test assesses delayed-type hypersensitivity and is used to determine prior exposure or immune sensitization to Histoplasma.
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Service type: Diagnostic skin antigen testing (fungal antigen skin test)
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Typical site of service: Laboratory or outpatient clinic with skin testing capability
Clinical & Coding Specifications
Clinical Context
A 45-year-old patient with a history of chronic respiratory symptoms and travel or environmental exposure is referred to an infectious disease or pulmonary clinic for evaluation of possible prior exposure to the fungus Histoplasma capsulatum. The clinician orders intradermal histoplasmin skin testing to assess delayed-type hypersensitivity indicating prior sensitization. In the clinic workflow, a trained nurse or clinician prepares the antigen, documents informed consent and allergy history, performs the intradermal injection on the volar forearm, and records the injection site. The patient returns at 48 to 72 hours for measurement of induration and erythema; the clinician documents the size of induration in millimeters and clinical interpretation (positive, negative, or indeterminate). Specimen handling is minimal because this is an in vivo skin test; billing uses laboratory test code 86510 for the analytic interpretation of the skin test response when reported by the laboratory or lab analyst. Typical site of service is an outpatient clinic, ambulatory care center, or public health clinic. Typical patient scenario includes evaluation for prior histoplasmosis exposure in patients with respiratory complaints, pre-employment or epidemiologic screening in endemic areas, or assessment of immune response in patients with suspected compromised cellular immunity.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component |