Summary & Overview

CPT 86619: Borrelia Relapsing Fever Antibody Immunoassay

CPT code 86619 denotes a laboratory immunoassay to detect antibodies to Borrelia species that cause relapsing fever. As a targeted serologic diagnostic, this code supports clinical decision-making for suspected relapsing fever and public health surveillance of Borrelia infections. Nationally, accurate coding for specialized infectious disease testing affects laboratory reporting, reimbursement consistency, and epidemiologic tracking.

Key payers in this review include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication outlines payer coverage patterns, coding and billing considerations, and clinical context for when testing is appropriate. Benchmarks and reimbursement trends are summarized where available; readers will also find notes on typical sites of service and the laboratory workflow implications for ordering and reporting results.

Readers will learn: the clinical purpose of the assay, where the test is commonly performed, which payers are typically involved in coverage discussions, and what informational gaps exist in the available input. Data not available in the input is indicated explicitly in relevant sections of the full publication.

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Billing Code Overview

CPT code 86619 describes an immunoassay performed by a laboratory analyst to detect antibodies to Borrelia species associated with relapsing fever. The test evaluates a patient’s blood specimen for serologic evidence of infection by Borrelia organisms that cause relapsing fever.

Service type: Laboratory diagnostic immunoassay

Typical site of service: Clinical or hospital laboratory, reference laboratory, or other outpatient laboratory setting

Clinical & Coding Specifications

Clinical Context

A patient presents to an outpatient infectious disease clinic or primary care office with recurrent fevers, headache, myalgias, and a history of exposure in an area known for relapsing fever (tick or louse exposure). The clinician documents symptoms, exposure history, and performs a physical exam noting fever and possibly splenomegaly. A blood specimen is collected and sent to the laboratory for serologic testing. The laboratory analyst performs an immunoassay to detect antibodies to Borrelia species associated with relapsing fever, reported under CPT 86619. Typical workflow: specimen accessioning, serum separation, running the immunoassay on an automated platform, quality controls, result verification by a qualified technologist, and transmission of results to the ordering provider. Typical sites of service are outpatient clinics, hospital outpatient labs, public health laboratories, and reference laboratories. Patients are often adults or children with suspected relapsing fever; testing may be ordered alongside acute diagnostics (blood smear, PCR) and after initial empiric therapy to document seroconversion or support diagnosis.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when billing separately for the professional interpretation/oversight of the immunoassay if the facility bills technical component.
`TC`	Technical component	Use when billing only the technical component (laboratory processing, reagents, instrumentation) of the test.
`59`	Distinct procedural service	Use when a separate, distinct laboratory procedure is performed at a different session or anatomic site and must be identified as distinct from other billed services.
`90`	Reference laboratory	Use when the service is performed by an independent outside laboratory (reference lab) as opposed to the ordering facility.
`52`	Reduced services	Use when the test was partially performed or limited in scope (e.g., blocked by insufficient specimen) and payment reduction is appropriate.
`53`	Discontinued procedure	Use when testing was started but discontinued for documented clinical reasons (e.g., hemolyzed sample discovered before assay completion).
`59`	Distinct procedural service	Use when another laboratory test performed on the same day requires distinct identification to avoid bundling.
`90`	Reference laboratory	Use when an outside laboratory performs the testing and reports results back to the originating facility.
`QX`	CLIA waived or moderate complexity personnel	Use when the personnel performing the test meets CLIA requirements and billing needs to indicate personnel qualifications (per payer rules).
`QY`	CLIA certificate of compliance	Use when the test was performed in a laboratory certified under the Clinical Laboratory Improvement Amendments (CLIA) and payer requires this indicator.
`AS`	Physician assistant, nurse practitioner, clinical nurse specialist services	Use when an advanced practice clinician orders and/or supervises specimen collection in applicable billing contexts.
`22`	Increased procedural services	Use when performing this assay required substantially greater resources or complexity than typical (e.g., extensive troubleshooting, validation).
`78`	Unplanned return to the operating/procedure room	Not typically applicable to this lab test; included when institutional billing systems require tracking of unplanned returns related to specimen collection procedures.
`59`	Distinct procedural service	Use to indicate a distinct lab service not normally reported together; apply carefully per payer guidance.

Taxonomy Code	Specialty	Notes
207RG0300X	Infectious Disease	Infectious disease physicians commonly order and interpret Borrelia serologies.
207L00000X	Emergency Medicine	Emergency clinicians evaluate febrile patients with exposure history and may order acute testing.
208D00000X	Family Medicine	Primary care and family medicine clinicians frequently initiate testing in outpatient settings.
207RH0000X	Internal Medicine	Hospitalists and internists order serologies for inpatients and outpatients.
261QM0800X	Pathology	Pathologists and laboratory directors oversee test validation, quality control, and result review.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`A69.2`	Other specified spirochetal infections	Includes relapsing fever due to Borrelia species; directly relevant as the primary indication for `86619`.
`A69.20`	Relapsing fever, unspecified	Used when relapsing fever is diagnosed but causative species is unspecified; serology supports diagnosis.
`A69.21`	Louse-borne relapsing fever	Specific form of relapsing fever; serologic testing for Borrelia species assists in confirmation.
`A69.22`	Tick-borne relapsing fever	Common exposure history for Borrelia species causing relapsing fever; serology used for diagnosis.
`R50.9`	Fever, unspecified	Symptom code frequently used at presentation prompting serologic testing for infectious etiologies including relapsing fever.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`86619`	Immunoassay for antibodies to Borrelia species (relapsing fever)	Primary code describing the immunoassay performed to detect antibodies to relapsing fever Borrelia.
`86617`	Immunoassay for antibodies to Borrelia burgdorferi (Lyme disease)	Often ordered concurrently or as part of differential serologic testing when assessing tick-borne illnesses.
`87481`	Infectious agent detection by nucleic acid (PCR), Borrelia burgdorferi	Molecular testing may be ordered alongside serology for early or acute-stage diagnosis.
`87070`	Culture, bacterial; blood	Blood culture can be performed when bacteremia is suspected in febrile patients and may accompany serologic testing.
`80053`	Comprehensive metabolic panel	Routine laboratory panels are commonly ordered concurrently to assess organ function during infectious disease evaluation.