Summary & Overview
CPT 0621U: TruD MDS Lyme Disease DNA Methylation Test
CPT code 0621U designates a Proprietary Laboratory Analyses (PLA) test for TruD MDS Lyme Disease from TruDiagnostic™ Inc. The assay evaluates DNA methylation at more than 10,000 sites from a whole blood specimen and uses a proprietary algorithm to generate a positive or negative risk report for Lyme borreliosis. As a PLA code, 0621U is specific to a single manufacturer’s assay and is used to identify this unique molecular diagnostic service on claims.
This publication covers national payer handling and policy context for CPT code 0621U, with payers referenced including Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical application of the test, typical sites of service (clinical and reference laboratories with outpatient specimen collection), and the operational implications of PLA coding for coverage and claims processing.
The briefing summarizes what to expect in payer engagement and billing: how the PLA designation affects code specificity, areas of likely coverage review for an infectious disease methylation assay, and common documentation elements payers may require. It also outlines benchmarks and policy updates relevant to proprietary molecular diagnostics and highlights clinical context for Lyme borreliosis testing. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 0621U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to the TruD MDS Lyme Disease test from TruDiagnostic™ Inc. The assay analyzes DNA methylation at more than 10,000 sites using a whole blood sample and applies a proprietary algorithm to report a positive or negative risk for Lyme borreliosis (Lyme disease).
Service Type: Infectious disease molecular diagnostic test (proprietary laboratory analysis)
Typical Site of Service: Clinical laboratory or reference laboratory, whole blood specimen collection in outpatient or ambulatory collection settings
Clinical & Coding Specifications
Clinical Context
A typical patient scenario involves an adult or pediatric patient presenting with signs or history suspicious for Lyme borreliosis (for example, tick exposure, erythema migrans, migratory arthralgia, cranial nerve palsy, or persistent non-specific symptoms after prior treatment). A clinician in an outpatient specialty setting (infectious disease clinic, primary care, or a genomic testing referral center) orders the TruD MDS Lyme Disease test (0621U) when there is diagnostic uncertainty after standard serologic testing or when a provider seeks additional molecular-level risk stratification.
Workflow: the clinician documents the clinical indication, obtains a whole blood sample per the laboratory’s specimen collection instructions, and sends the specimen to TruDiagnostic™ Inc. The laboratory performs DNA methylation analysis at >10,000 CpG sites, applies its proprietary algorithm, and returns a report indicating a positive or negative risk for Lyme borreliosis. Results are reviewed by the ordering clinician, correlated with clinical findings, and used to support diagnostic decision-making and management planning.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing only the professional interpretation component if separated by the laboratory (rare for PLAs where single-entity billing applies). |
TC | Technical component | When billing only the technical component if the performing laboratory bills separately. |
59 | Distinct procedural service | When this PLA test is billed on the same day as another diagnostic test and the service is distinct and separate. |
24 | Unrelated evaluation and management service by the same physician during a postoperative period | If an unrelated E/M occurs in the global period for a surgical episode (unlikely but included for completeness). |
25 | Significant, separately identifiable E/M service on the same day | When an E/M is performed and documented separately from ordering the test. |
GA | Waiver of liability statement on file (advanced beneficiary notice equivalent) | When the provider has a voluntary payer-specific waiver or attestation regarding test payment responsibility. |
BK | Used by some payers to indicate redesignation of PLA code ownership (payer-specific) | When a payer requires a specific modifier for proprietary test identification (payers vary). |
QW | CLIA waived test | Not typical for this PLA; used only if a test meets CLIA waived criteria (usually not applicable). |
90 | Reference (outside) laboratory | When the performing lab is an outside/reference laboratory billing for the technical component. |
91 | Repeat clinical diagnostic laboratory test | When the identical test is repeated on the same day and payer requires modifier for repeat testing. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207Q00000X | Infectious Disease Specialist | Common ordering specialty for suspected Lyme disease evaluation. |
207L00000X | Allergy & Immunology | May order testing when evaluating tick-borne immune-mediated presentations. |
207RC0000X | Pathology-Laboratory Medicine | Laboratory directors and clinical pathologists oversee molecular testing quality and reporting. |
208D00000X | Family Medicine | Primary care physicians frequently order or coordinate testing for Lyme disease. |
207K00000X | Internal Medicine | Internists evaluate adult patients with suspected tick-borne illness and order advanced diagnostics. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
A69.20 | Lyme disease, unspecified | General code for Lyme borreliosis; directly relevant when evaluating for Lyme infection. |
A69.21 | Lyme meningitis | Neurologic manifestation of Lyme disease; testing may support diagnosis in complex cases. |
A69.22 | Lyme carditis | Cardiac manifestation; molecular/epigenetic risk information may contribute to diagnostic assessment. |
A69.23 | Other neurologic disorders in Lyme disease | Includes cranial neuropathies and radiculoneuritis; relevant when serology is equivocal. |
A69.29 | Other conditions associated with Lyme disease | For other clinical presentations where confirmatory testing is sought. |
R53.83 | Other fatigue | Non-specific symptom that may prompt evaluation for Lyme disease in appropriate epidemiologic context. |
M79.7 | Fibromyalgia | Chronic pain syndromes sometimes in the differential diagnosis for post-treatment Lyme symptoms; testing may be requested during evaluation. |
Z20.820 | Contact with and (suspected) exposure to Lyme disease | Use when documenting history of exposure prompting diagnostic testing. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
36415 | Collection of venous blood by venipuncture | Typical specimen collection method for whole blood sent for the test. |
81025 | Urine pregnancy test, by visual color comparison methods (single test) | Performed prior to some treatments (e.g., before antibiotics that are teratogenic) in women of childbearing potential when clinically indicated; may be part of workflow though not required by the test itself. |
80053 | Comprehensive metabolic panel | Common accompanying laboratory tests to evaluate baseline organ function prior to treatment decisions influenced by diagnostic results. |
86328 | Antibody; Lyme disease (Borrelia spp.), multiplex or specific serologic assays | Standard serologic testing often performed before or alongside advanced molecular/epigenetic testing for Lyme disease. |
81479 | Unlisted molecular pathology procedure | Occasionally used for reporting molecular tests when no specific PLA or CPT exists, though 0621U is the specific PLA for TruD MDS Lyme and should be used when applicable. |