CPT code 87542 represents a molecular diagnostic assay that quantifies Legionella pneumophila using a nucleic acid probe technique. This test supports detection and measurement of a pathogen associated with Legionnaires’ disease and is important for outbreak investigation, infection control in facilities, and targeted clinical management. Nationally, accurate and timely laboratory identification of L. pneumophila is a public health priority given potential for rapidly spreading, aerosolized exposures.

Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical context for the assay, typical settings where the service is performed, and the kinds of benchmarks and payment considerations that are commonly reviewed by payers and laboratories. The publication covers service-level details, common billing scenarios, and the policy and coding issues that affect coverage and claims processing for molecular diagnostic tests.

The report also highlights where input data are unavailable and identifies topics for operational attention, including documentation needed to support medical necessity, typical sites of service, and how laboratories report molecular quantification assays. Data not available in the input.