CPT 0044U: Tick–Borne Relapsing Fever Borrelia ImmunoBlot IgG Test

CPT code 0044U identifies a Proprietary Laboratory Analyses (PLA) test: the Tick–Borne Relapsing Fever (TBRF) Borrelia ImmunoBlots IgG produced by IGeneX Inc. The code designates a single manufacturer-specific serologic assay that detects IgG antibodies to four Borrelia species implicated in tick-borne relapsing fever. Nationally, PLA codes like 0044U matter because they enable distinct reporting, tracking, and payment for proprietary diagnostics that do not map to general test families.

Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the test’s clinical purpose, typical service setting, and payer landscape. The publication outlines common billing modifiers and procedural context where available, summarizes implications for claims submission and coding accuracy, and places the assay in clinical context for diagnosing Borrelia-related infections. This content provides actionable reference material for coding professionals, laboratory billing teams, and policy analysts seeking clarity on how a PLA-designated serologic assay is reported and where it fits within national diagnostic coding and payer frameworks.

Data not available in the input: Associated taxonomies, ICD-10 diagnoses, related codes, and specific payer policy details.

Billing Code Overview

CPT code 0044U is a Proprietary Laboratory Analyses (PLA) code that describes a single, manufacturer- or laboratory-specific test: the Tick–Borne Relapsing Fever (TBRF) Borrelia ImmunoBlots IgG from IGeneX Inc. The test detects IgG antibodies to four species of Borrelia, the tick-borne bacteria associated with relapsing fever and related Borrelia infections.

Service Type: Laboratory serologic diagnostic test for tick-borne Borrelia infection

Typical Site of Service: Clinical laboratory or reference laboratory setting, with specimen collection commonly performed in outpatient clinics, physician offices, or phlebotomy centers.

Clinical Context

A 38-year-old patient presents to an infectious disease clinic with a history of multiple tick exposures while hiking in a region endemic for relapsing fever. The patient reports recurrent febrile episodes, headache, myalgias, and a transient rash over the prior several weeks. Prior routine Lyme serology was negative or equivocal. The clinician orders the proprietary Tick–Borne Relapsing Fever (TBRF) Borrelia ImmunoBlots IgG (0044U) from IGeneX Inc. to detect IgG antibodies to four Borrelia species associated with tick-borne relapsing fever.

Workflow:

The ordering clinician documents clinical suspicion for relapsing fever or nonspecific tick-borne illness in the outpatient chart and places the laboratory order for 0044U.
A phlebotomist obtains a serum specimen at an ambulatory clinic or outpatient lab; typical site of service is an outpatient clinic, physician office, or independent laboratory collection center.
The specimen is sent to the performing laboratory (IGeneX Inc.) with appropriate test requisition and clinical history; the lab performs the immunoblot and reports qualitative IgG results for the four Borrelia species.
Results are reviewed by the ordering clinician; positive IgG may support a diagnosis of prior or ongoing tick-borne relapsing fever infection and guide additional clinical evaluation or therapy. Negative results may prompt consideration of acute testing, alternative diagnoses, or repeat testing based on timing of exposure and symptom onset.
Billing for the test uses the PLA code 0044U with appropriate modifier(s) as clinically indicated and the laboratory’s CLIA and payer contractual details applied during claims submission.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when reporting only the professional interpretation component if split billing between facility and physician occurs.

| TC | Technical component | Use when reporting only the technical component (laboratory processing) by the performing lab.

| QY | Ordering/servicing laboratory modifier for CLIA-waived tests (historical use) | Use per specific payer rules when distinguishing test performance location or Medicare requirements if accepted by the payer.

| QX | Modifier certifying assistant-at-surgery (when applicable) | Rare for lab testing; include only if billing rules require distinguishing personnel roles per payer guidance.

| QK | Medical direction of two, three, or four qualified individuals (historical) | Not typical for lab tests; include only if the performing lab’s billing meets payer-specific medical direction rules.

| 52 | Reduced services | Use when the laboratory performed a modified or partial procedure relative to the full test method and payer allows reduced service reporting.

| 53 | Discontinued procedure | Use when specimen collection or testing was started but discontinued and payer permits a partial claim; uncommon for finalized immunoblots.

| 59* | Distinct procedural service (Note: not listed in input modifiers) | Data not available in the input.

| 22 | Increased procedural services | Use when work, time, technical effort, or complexity substantially exceeds typical expectations for a single immunoblot and payer allows an increased services modifier.

| 78 | Unplanned return to the operating/procedure room by the same physician following initial procedure (not typically applicable) | Rarely applicable to lab testing; include only if payer rules require reporting for repeat collection under special circumstances.

Associated provider taxonomies

Taxonomy Code	Specialty	Notes
207Q00000X	Infectious Disease	Specialists who commonly order and interpret tick-borne serology tests, including `0044U`.

| 207L00000X | Emergency Medicine | ED clinicians may order testing for suspected acute tick-borne illnesses during evaluation.

| 207LP2900X | Family Medicine | Primary care and family physicians who evaluate patients with tick exposure and order confirmatory serology.

| 207T00000X | Internal Medicine | Hospitalists and internists who assess patients with febrile illnesses and coordinate diagnostic testing.

| 263M00000X | Clinical Laboratory | Laboratory directors and clinical pathologists associated with performance and reporting of 0044U.

*Notes: Only the most clinically relevant modifiers from the provided list are selected. Some listed modifiers in the raw input have limited applicability to a proprietary laboratory immunoblot; payer-specific rules govern final modifier use.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`A69.23`	Lyme disease, unspecified	Lyme serology is part of the differential for tick-borne infections; clinicians may order `0044U` when Lyme tests are negative or to evaluate for other Borrelia species.

| A69.29 | Other specified spirochetal infections | Includes other Borrelia infections that could present similarly to relapsing fever; 0044U detects IgG to relapsing-fever Borrelia species.

| A77.0 | Spirochetal zootic relapsing fever | Directly relevant as it corresponds to tick-borne relapsing fever; 0044U supports serologic diagnosis.

| R50.9 | Fever, unspecified | Non-specific fever coding used when ordering diagnostic testing for suspected infectious causes including relapsing fever.

| R50.81 | Fever presenting with conditions classified elsewhere | Used when fever is documented alongside a specific infectious diagnosis being evaluated with 0044U.

| R53.1 | Weakness | Symptom code commonly accompanying systemic infections and part of the clinical picture prompting serologic testing.

| B99 | Other infectious diseases (unspecified) | Used as a nonspecific infectious disease code when the precise pathogen is pending and testing like 0044U is ordered.

| Z20.820 | Contact with and (suspected) exposure to ticks that may carry infection | Relevant when there is documented tick exposure leading to ordering of 0044U.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`80053`	Comprehensive metabolic panel (CMP)	Performed alongside `0044U` to assess baseline organ function prior to therapy when systemic infection is suspected.

| 86430 | Brucella antibody, serological test (note: example serology code) | Performed in differential serologic workup for febrile tick-borne or zoonotic illnesses; indicates additional serology panels commonly ordered in parallel.

| 87802 | Infectious agent antigen detection by immunoassay with direct optical observation; per single-step method (example rapid antigen) | Represents point-of-care testing that may precede more specific laboratory immunoblots such as 0044U.

| 36415 | Collection of venous blood by venipuncture | The specimen collection code commonly billed or documented when drawing blood for 0044U.

| 99000 | Handling and/or conveyance of specimen for transfer from physician's office to a laboratory (historical/limited use) | Used when additional specimen handling or courier services are billed in association with sending 0044U to a reference laboratory.

Note: If payer or local billing rules require alternate or specific CPT codes for related services (collection, processing, or additional serologic testing), those codes are billed in the clinical workflow surrounding 0044U.

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Summary & Overview