Summary & Overview

CPT 0310U: HART KD® Plasma Biomarker Risk Score for Kawasaki Disease

CPT code 0310U is a Proprietary Laboratory Analyses (PLA) code for the HART KD® test from Prevencio Inc., a plasma-based biomarker assay that uses an algorithm to produce a risk score for diagnosing Kawasaki Disease (KD). This pediatric diagnostic test matters nationally because KD can lead to serious coronary artery complications if not identified and managed promptly; a standardized PLA code enables consistent reporting and tracking of use and coverage. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will learn how CPT code 0310U is defined and used, the clinical context of the HART KD® assay, and the typical service delivery setting. The publication summarizes payer coverage patterns and benchmark considerations, highlights policy and coding implications for proprietary laboratory tests, and outlines common billing modifiers associated with laboratory services. The content provides clinical context around KD diagnosis and the role of biomarker-based algorithmic tests in supporting care decisions. Data not available in the input are identified where applicable, and technical billing elements such as associated taxonomies, ICD-10 diagnosis codes, and related codes are noted as unavailable when not provided.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare0310UCPTProprietary Laboratory AnalysisKawasaki Diseasebiomarker assaylaboratory testdiagnostic algorithmpediatric cardiology

Billing Code Overview

CPT code 0310U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to the HART KD® test from Prevencio Inc. The test measures levels of three specified plasma biomarkers and uses an algorithmic analysis to generate a risk score for diagnosing Kawasaki Disease (KD), a pediatric inflammatory condition that can cause coronary artery damage.

Service Type: Proprietary laboratory diagnostic test using plasma biomarker analysis with algorithmic risk scoring

Typical Site of Service: Clinical laboratory or hospital outpatient laboratory (specimen collected in a clinical setting and analyzed in a specialized laboratory)

Clinical & Coding Specifications

Clinical Context

A 3-year-old child presents to the pediatric emergency department with 5 days of persistent high fever, conjunctival injection, erythematous cracked lips, swollen hands and feet, and a polymorphous rash. The pediatrician suspects Kawasaki Disease (KD) and orders laboratory evaluation to support diagnosis and risk stratification. A peripheral blood draw is performed; a plasma specimen is sent to the reference laboratory performing the proprietary HART KD® test (Prevencio Inc.). The laboratory measures the three biomarkers specified by the proprietary assay and applies the manufacturer’s algorithm to generate a risk score indicating likelihood of KD and potential coronary artery involvement. Results are returned to the ordering clinician to inform cardiology consultation and decisions about echocardiography, intravenous immunoglobulin (IVIG) therapy, and inpatient monitoring.

Typical site of service: outpatient pediatric clinic, urgent care, emergency department, or hospital laboratory when a plasma sample is drawn and sent to the performing laboratory.

Service type: proprietary laboratory analysis (PLA) — analytic laboratory test performed and reported by the single-source manufacturer/lab for diagnostic risk scoring of Kawasaki Disease.

Typical clinical workflow:

The clinician documents signs and symptoms consistent with suspected KD and places the order for the HART KD® test.
A blood specimen is collected (plasma) and prepared per lab instructions; couriered to the performing laboratory if offsite.
The performing laboratory runs the proprietary assay, applies the algorithm, and issues a report with the KD risk score.
The ordering clinician reviews the report, integrates it with clinical and imaging data (for example, echocardiography), and documents decisions about IVIG therapy, cardiology referral, and follow-up monitoring.

Coding Specifications

Modifier	Description	When to Use
`00`	No modifiers applicable	Rarely used; default when no other modifier applies
`26`	Professional component	Use when billing only the professional component of a split service (interpretation) if applicable — typically not applicable for fully performed PLA tests but used if a professional interpretation separate from the lab technical component is billed
`52`	Reduced services	Use when the service was partially reduced from the full procedure (for example, an incomplete specimen precluding full testing)
`53`	Discontinued procedure	Use when testing was started but discontinued for documented clinical reasons before completion
`62`	Two surgeons or providers	Rare for lab tests; use if two qualified independent practitioners are required and documented
`78`	Return to operating room for related procedure	Not typical for this test; reserved for intraoperative returns if applicable
`80`	Assistant at surgery	Not typically applicable for laboratory testing but listed if an assistant’s role is billed in a related procedural context
`QK`	Medical direction of two or more qualified health care professionals	Use if medical direction rules apply to related services and are documented
`QX`	CRNA service: personal services of a CRNA	Not applicable to the lab test itself; included for related anesthesia billing when relevant
`QY`	CRNA service: medical direction of two or more CRNAs	Same as above; applies to anesthesia contexts
`TC`	Technical component	Use when billing only the technical component of the test (laboratory processing) — commonly used by performing laboratories
`SH`	Diagnostic supply and equipment cost ancillary to the main procedure	Use when separate supply billing rules apply for associated diagnostic disposables used in specimen collection or processing
`SJ`	Sign, symptoms, or history modifier	Use when reporting additional documentation of clinical circumstances that affect coding or coverage determination
`TG`	Both technical and professional components not separately payable	Use when payer rules require a single bundled payment rather than separate TC/26 billing

Taxonomy Code	Specialty	Notes
208000000X	Pediatrics	Ordering clinicians for suspected KD; inpatient and outpatient pediatrics manage workup and treatment
207Q00000X	Pediatric Cardiology	Performs echocardiography and coronary artery assessment; consults on KD risk and management
207L00000X	Pathology/Clinical Laboratory	Laboratory medical directors and pathologists oversee test performance and result validation
208000000X-1	Emergency Medicine	Emergency physicians frequently order diagnostic labs for febrile children with suspected KD
208000000X-2	Family Medicine	Primary care providers who may order the test in outpatient settings

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`M30.3`	Mucocutaneous lymph node syndrome [Kawasaki]	Primary diagnosis for which the HART KD® test is intended to assist risk stratification and diagnostic support
`R50.9`	Fever, unspecified	Common presenting symptom prompting evaluation for Kawasaki Disease and ordering of KD-specific laboratory testing
`R21`	Rash and other nonspecific skin eruption	Typical feature of KD; supports clinical suspicion when present with fever and mucocutaneous findings
`H10.9`	Conjunctivitis, unspecified	Conjunctival injection is a classic KD sign; presence increases pretest probability and justifies targeted testing
`R68.83`	Swelling, not elsewhere classified	Extremity swelling and edema occur in KD and may prompt diagnostic laboratory evaluation
`I51.4`	Myocarditis, unspecified	Cardiac involvement is a serious KD complication; elevated suspicion leads to combined lab and imaging assessment
`Z03.89`	Encounter for observation for other suspected diseases and conditions ruled out	Used when KD is suspected and diagnostic evaluation (including HART KD® testing) is performed to rule in or out the diagnosis

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`0310U`	HART KD® (Prevencio Inc.) — Proprietary laboratory analysis reporting a risk score for Kawasaki Disease based on three plasma biomarkers and algorithmic analysis	Primary PLA code for the specific proprietary assay performed by the manufacturer or designated laboratory
`80053`	Comprehensive metabolic panel (CMP)	Commonly ordered alongside specialized PLA tests to assess general metabolic status and aid clinical evaluation in febrile pediatric patients
`85025`	Complete blood count (CBC) with automated differential	Routinely ordered in suspected KD to evaluate leukocytosis, anemia, and platelet counts; informs diagnosis and monitoring
`83970`	Cardiac enzyme assay (example: troponin)	May be ordered when there is concern for cardiac involvement; assists in evaluating myocardial injury in severe presentations
`93306`	Echocardiography, transthoracic, real-time with image documentation, complete	Performed to assess coronary artery dimensions and cardiac function in patients with suspected or confirmed KD; often ordered after lab results inform risk stratification
`96372`	Therapeutic injection, subcutaneous or intramuscular (e.g., for IVIG administration preparation may require injections)	Associated with treatment workflows when IVIG or adjunctive therapies are administered after diagnosis; included to reflect related interventional services