CPT code 86753 designates a laboratory immunoassay to detect serum antibodies to a protozoan when no more specific code applies. This code captures a range of serologic testing used to identify immune responses to protozoan pathogens and is relevant for infectious disease diagnosis, public health surveillance, and laboratory billing standards nationwide. Its use affects clinical reporting and laboratory workflows when targeted, organism-specific codes are not available.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication outlines payer coverage patterns, common modifiers observed with lab services, clinical context for ordering serologic assays, and operational benchmarks for laboratory processing and coding.

Readers will learn the clinical scope of CPT code 86753, typical sites of service where the test is performed, and how this code is applied when more specific protozoan antibody codes are absent. The report also summarizes payer coverage considerations, expected documentation elements, and where to find relevant coding guidance. Data not available in the input are noted where applicable.