Summary & Overview
CPT 0503U: PrecivityAD2 Blood Beta‑Amyloid and Tau Assay
CPT code 0503U designates a Proprietary Laboratory Analyses (PLA) test for PrecivityAD2™ developed by C2N Diagnostics LLC. The assay quantifies beta amyloid and tau proteins in blood using immunoprecipitation and LC–MS/MS and produces an algorithmic score estimating likelihood of amyloid plaques associated with Alzheimer disease. This PLA code is unique to the single manufacturer and test, which has implications for coverage, billing specificity, and laboratory reporting.
Key national payers in scope include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication summarizes how payers treat PLA-designated tests, typical billing practices for proprietary assays, and payer-specific considerations that influence access and reimbursement nationally.
Readers will find a concise explanation of the clinical context for blood-based Alzheimer biomarkers, benchmarking of common payer coverage approaches, a summary of coding and billing considerations tied to PLA status, and implications for clinical laboratories and ordering clinicians. The report highlights service settings where this test is delivered, common billing modifiers used with laboratory services (input list provided), and notes limitations where input data were not supplied.
Billing Code Overview
CPT code 0503U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to a single commercially available laboratory test. Report 0503U only for PrecivityAD2™ from C2N Diagnostics LLC. The test uses immunoprecipitation and liquid chromatography with tandem mass spectrometry (LC–MS/MS) to measure beta amyloid and tau–protein levels in blood and generates an algorithm score estimating the likelihood of amyloid plaque associated with Alzheimer disease.
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Service type: Proprietary laboratory diagnostic assay providing a quantitative algorithmic blood biomarker score for Alzheimer disease risk assessment
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Typical site of service: Clinical laboratory or outpatient phlebotomy collection site
Clinical & Coding Specifications
Clinical Context
A 68-year-old patient with progressive memory decline is referred by a neurologist for blood-based biomarker testing to assess the likelihood of cerebral amyloid plaque deposition. The clinician documents mild cognitive impairment versus early Alzheimer disease in the history of present illness and orders the proprietary PrecivityAD2™ test to measure plasma beta-amyloid and tau proteins using immunoprecipitation and liquid chromatography–tandem mass spectrometry (LC–MS/MS). A phlebotomy is scheduled at an outpatient laboratory or hospital draw station; the specimen is sent to C2N Diagnostics LLC for analysis. Results provide an algorithm-derived score indicating the probability of amyloid plaque presence, which the ordering clinician integrates with clinical assessment, neuroimaging, and neuropsychological testing to inform diagnostic discussions and care planning.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier; standard reporting | Use when no modifier applies to the laboratory service. |
| 26 | Professional component | Use when reporting only the professional interpretation component if applicable (rare for PLA codes; applies when separate professional interpretation is billed).
| 52 | Reduced services | Use when the test is partially performed or limited in scope compared with the full service.
| 53 | Discontinued procedure | Use when specimen collection or test processing was started but discontinued for patient-related reasons.
| 59 | Data not available in the input. | Data not available in the input.
| 62 | Two surgeons | Use when two qualified independent physicians perform distinct parts of a service; rarely applicable to lab testing workflows.
| 78 | Unplanned return to the operating/procedure room | Use when an unplanned return impacts related services; unlikely for this lab test but retained for clinical relevance.
| 80 | Assistant surgeon | Use when an assistant surgeon is involved; typically not applicable to laboratory testing.
| QK | Medical direction of two, three, or four technicians | Use when the ordering or performing physician provides medical direction over multiple laboratory technicians during complex testing processes.
| QX | Surgical assistant (physical presence) | Use when an assistant meets modifier QX criteria; generally not applicable for PLA reporting.
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 2084P0200X | Neurology | Neurologists commonly order Alzheimer disease biomarker testing to support diagnosis and management. |
| 207RC0000X | Clinical Neurophysiology | Clinicians in neurodiagnostic specialties may be involved in comprehensive cognitive evaluations that include biomarker testing.
| 207L00000X | Clinical Laboratory | Laboratory directors and clinical pathologists oversee specimen processing and analytical quality for specialized PLA tests.
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
G30.9 | Alzheimer disease, unspecified | Common diagnostic consideration when ordering plasma amyloid/tau testing to assess for amyloid pathology. |
| G31.84 | Mild cognitive impairment, so stated | Typical clinical indication for biomarker testing to help determine etiology and progression risk.
| F02.80 | Dementia in other diseases classified elsewhere without behavioral disturbance | Used when dementia is attributed to another disease; biomarkers help differentiate Alzheimer pathology from other causes.
| R41.3 | Other amnesia | Cognitive symptoms such as amnesia may prompt evaluation including blood-based biomarkers.
| R41.81 | Age-related cognitive decline | Biomarker testing can assist in distinguishing age-related decline from neurodegenerative disease.
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
0503U | PrecivityAD2™; plasma beta-amyloid and tau algorithm score by immunoprecipitation and LC–MS/MS (Proprietary Laboratory Analyses code) | The primary PLA code for the proprietary blood-based Alzheimer disease biomarker test performed by C2N Diagnostics LLC. |
| 80053 | Comprehensive metabolic panel; 14 tests | Often ordered concurrently to assess metabolic contributors to cognitive change and to evaluate general medical status before interpretation of biomarker results.
| 80307 | Drug assay, qualitative; multiple drug classes | May be ordered to exclude substance-related cognitive impairment when clinically indicated prior to biomarker-based diagnostic interpretation.
| 81002 | Urinalysis, non-automated, without microscopy | Ordered as part of routine evaluation to screen for reversible causes of cognitive symptoms.
| 96116 | Neurobehavioral status exam, per hour | Neuropsychological testing commonly complements biomarker testing to document cognitive deficits and support diagnostic conclusions.