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.

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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.

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

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

Customize your policy alerts

Sign up for cpt 0044U policy alerts

Get alerted when payer policies referencing 0044U are released or updated.

Monitor payer policy activity

Receive email alerts as soon as relevant payer policies are published or updated.

Billing Code Overview

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 & Coding Specifications

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.

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.

Related Modifiers

5 rows

Modifier
26
52
53
22
78

Related Provider Taxonomies

8 rows

Taxonomy Code
207Q00000X
207L00000X
207LP2900X
207T00000X
193200000X
207ZP0105X
225XG0600X
156FX1201X

CPT 0001U: PreciseType HEA Multiplex Erythrocyte Antigen Assay

CPT-0002U-POLYPDX-URINE-METABOLOMIC-ASSAY-ADENOMATOUS-POLYP-RISK

CPT 0002U: Urine Metabolomic Polyp Risk Assay (PolypDX™)

CPT-0003U-OVAR-A-NEXT-GENERATION-OVARIAN-CANCER-RISK-ASSAY

CPT 0003U: Overa™ (OVA1 Next Generation) Ovarian Cancer Risk Assay

CPT-0005U-PROSTATE-EXOSOMEDX-INTELLISCORE-GENE-EXPRESSION-URINE-TEST

CPT 0005U: ExosomeDx Prostate (IntelliScore) Urine Gene Expression Risk Test

CPT-0007U-TOXPROTECT-URINE-DRUG-SCREEN-WITH-DNA-AUTHENTICATION

CPT 0007U: ToxProtect Urine Drug Screen with DNA Authentication

CPT-0008U-H-PYLORI-ANTIBIOTIC-RESISTANCE-SEQUENCING-PANEL

CPT 0008U: H. pylori Antibiotic Resistance Panel, Gene Sequence Analysis

CPT-0009U-DEPARRAY-HER2-FISH-TUMOR-CELL-ISOLATION

CPT 0009U: DEPArray HER2 Tumor‑Cell Isolation with FISH Analysis

CPT-0010U-BACTERIAL-TYPING-WHOLE-GENOME-SEQUENCING-MAYO-CLINIC

CPT 0010U: Bacterial Typing by Whole Genome Sequencing, Mayo Clinic

CPT-0011U-CORDANT-CORE-ALGORITHMIC-ORAL-FLUID-DRUG-TEST

CPT 0011U: Cordant CORE™ Oral Fluid Drug Test with Algorithmic Steady‑State Comparison

CPT-0016U-BCR-ABL1-MAJOR-MINOR-FUSION-TRANSCRIPT-TESTING

CPT 0016U: BCR–ABL1 Major and Minor Breakpoint Fusion Transcript Testing

Showing 1–10 of 536

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

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Clinical & Coding Specifications

Clinical Context

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.

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.

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

Related Modifiers

5 rows

Modifier
26
52
53
22
78

Related Provider Taxonomies

8 rows

Taxonomy Code
207Q00000X
207L00000X
207LP2900X
207T00000X
193200000X
207ZP0105X
225XG0600X
156FX1201X

CPT 0001U: PreciseType HEA Multiplex Erythrocyte Antigen Assay

CPT-0002U-POLYPDX-URINE-METABOLOMIC-ASSAY-ADENOMATOUS-POLYP-RISK

CPT 0002U: Urine Metabolomic Polyp Risk Assay (PolypDX™)

CPT-0003U-OVAR-A-NEXT-GENERATION-OVARIAN-CANCER-RISK-ASSAY

CPT 0003U: Overa™ (OVA1 Next Generation) Ovarian Cancer Risk Assay

CPT-0005U-PROSTATE-EXOSOMEDX-INTELLISCORE-GENE-EXPRESSION-URINE-TEST

CPT 0005U: ExosomeDx Prostate (IntelliScore) Urine Gene Expression Risk Test

CPT-0007U-TOXPROTECT-URINE-DRUG-SCREEN-WITH-DNA-AUTHENTICATION

CPT 0007U: ToxProtect Urine Drug Screen with DNA Authentication

CPT-0008U-H-PYLORI-ANTIBIOTIC-RESISTANCE-SEQUENCING-PANEL

CPT 0008U: H. pylori Antibiotic Resistance Panel, Gene Sequence Analysis

CPT-0009U-DEPARRAY-HER2-FISH-TUMOR-CELL-ISOLATION

CPT 0009U: DEPArray HER2 Tumor‑Cell Isolation with FISH Analysis

CPT-0010U-BACTERIAL-TYPING-WHOLE-GENOME-SEQUENCING-MAYO-CLINIC

CPT 0010U: Bacterial Typing by Whole Genome Sequencing, Mayo Clinic

CPT-0011U-CORDANT-CORE-ALGORITHMIC-ORAL-FLUID-DRUG-TEST

CPT 0011U: Cordant CORE™ Oral Fluid Drug Test with Algorithmic Steady‑State Comparison

CPT-0016U-BCR-ABL1-MAJOR-MINOR-FUSION-TRANSCRIPT-TESTING

CPT 0016U: BCR–ABL1 Major and Minor Breakpoint Fusion Transcript Testing

Showing 1–10 of 536

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

Published by

Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

OpenPayer

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

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Billing Code Overview

OpenPayer

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

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Billing Code Overview

Clinical & Coding Specifications

Clinical Context

Related Diagnoses

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related Codes

References

Clinical & Coding Specifications

Clinical Context

Related Diagnoses

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related Codes

References