Summary & Overview
CPT 86403: Particle Agglutination (PA) Serologic Screening Test
CPT code 86403 represents a particle agglutination (PA) serologic screening test performed on a patient specimen, most often blood. Nationally, this laboratory code is relevant for clinical diagnostics and payer coverage decisions because PA tests support immune-status assessment and the detection of infectious or immunologic conditions. Use of 86403 impacts lab billing workflows, outpatient laboratory reporting, and claims adjudication for serology testing.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for the PA test, typical sites of service, and the kinds of benchmarks and policy implications that affect reimbursement and coding practices. The publication also summarizes common modifiers associated with laboratory services and highlights data availability issues where input data are not provided.
This report is written for a national audience and focuses on: the clinical role of CPT code 86403; how payers commonly approach laboratory serology claims; expected service settings; and the practical elements of billing and documentation that influence claim processing. Data not provided in the input are noted where applicable.
Billing Code Overview
CPT code 86403 describes a particle agglutination (PA) test performed by a laboratory analyst on a patient specimen, typically a blood specimen. The test is a laboratory screening assay used to evaluate a patient’s immune status or to assist in the detection of a variety of infectious and immunologic conditions.
Service type: Laboratory diagnostic test (serologic screening)
Typical site of service: Clinical laboratory or hospital laboratory; specimen collection commonly occurs in outpatient clinics, physician offices, or hospital outpatient settings.
Clinical & Coding Specifications
Clinical Context
A typical scenario involves an outpatient or hospital laboratory receiving a blood specimen from a patient for immune-status screening or for evaluation of infectious or autoimmune conditions. A primary care provider, infectious disease specialist, or rheumatologist orders the particle agglutination (PA) test when there is need to detect specific antibodies or antigens that aggregate particulate carriers (for example, to assess prior exposure or immune response). The clinical workflow: the patient presents to a clinic, ambulatory lab, emergency department, or inpatient unit; phlebotomy collects a serum or plasma specimen; the specimen is labeled and sent to the clinical laboratory; a qualified lab analyst performs the PA assay under the laboratory’s standard operating procedure; results are validated, documented in the laboratory information system, and reported to the ordering provider for interpretation and subsequent care decisions. Typical sites of service include outpatient clinics, hospital laboratories, reference labs, and ambulatory phlebotomy centers. Typical patient presentations include screening for prior infection, assessing immune response where antibody detection is indicated, or part of a diagnostic workup for suspected infectious or autoimmune disease.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component |