Summary & Overview

CPT 0583U: Rapid Genome Sequencing Family Member Comparator

CPT code 0583U designates a Proprietary Laboratory Analyses (PLA) test — the Rapid Genome Sequencing Family Member Comparator from Mayo Clinic — which performs rapid whole genome sequencing of a family member to compare against the proband’s genomic data. This code is significant nationally because rapid genomic comparator testing can accelerate diagnosis for critically ill patients, influence clinical decision-making, and intersect with evolving coverage policies for advanced molecular diagnostics. Key payers in the national landscape include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of what this code represents, payer coverage considerations, and the clinical context in which the service is used. The publication summarizes common billing modifiers associated with similar services, typical site-of-service settings, and practical coding notes tied to the PLA designation. It also outlines the implications of PLA coding — namely that the code is proprietary to a single manufacturer or laboratory — and highlights how that affects claim recognition and policy language. Data not available in the input is identified where applicable, and the content focuses on national relevance rather than state-specific policy.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare0583UCPTProprietary Laboratory Analysesrapid whole genome sequencinggenomic testingmolecular diagnosticsfamily member comparatorlaboratory billingprecision medicine

Billing Code Overview

CPT code 0583U is a Proprietary Laboratory Analyses (PLA) code for the Rapid Genome Sequencing Family Member Comparator offered by Mayo Clinic. The test uses rapid whole genome sequencing of a family member to compare genomic results with the proband (the primary patient) to aid in diagnostic interpretation.

Service type: Genomic diagnostic testing using rapid whole genome sequencing for family-member comparator analysis

Typical site of service: Clinical molecular diagnostics laboratory or specialized genomic testing center; results support inpatient or outpatient clinical care as needed

Clinical & Coding Specifications

Clinical Context

A newborn in the neonatal intensive care unit (NICU) presents with unexplained, rapidly progressive multisystem abnormalities including refractory seizures, hypotonia, metabolic instability, and organ dysfunction. Initial metabolic and infectious workups are inconclusive. The neonatology team, genetics consult service, and clinical laboratory coordinate expedited genomic testing. A rapid whole genome sequencing (rWGS) is performed on the proband to identify a likely pathogenic variant, and family member comparator testing is ordered to sequence a parent or sibling to aid interpretation of variants of uncertain significance and determine inheritance (de novo vs inherited). The comparator sample is collected from a blood draw or buccal swab from the chosen family member, sent to the Mayo Clinic laboratory under urgent transport with clear labeling for the 0583U Rapid Genome Sequencing Family Member Comparator. Results are integrated into the clinical genetics report to support diagnostic classification, immediate management decisions (e.g., targeted therapies, medication avoidance), and genetic counseling for the family. Typical site of service is the hospital inpatient setting (NICU or pediatric ward) or an affiliated outpatient genetics clinic when rapid sequencing is indicated but the patient is not currently hospitalized. Service type: Proprietary Laboratory Analyses (PLA) — laboratory diagnostic genomic testing performed by Mayo Clinic specific assay 0583U.

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier — standard reporting	Use when no special billing circumstance applies and full test performed as usual.
`22`	Increased procedural services	Use when the laboratory documents substantially greater effort or resources than typical for the assay (e.g., extensive reanalysis or extended interpretation time) in accordance with payer policies.
`52`	Reduced services	Use when the family member comparator testing is partially performed or limited relative to the full service (e.g., incomplete sample or partial analyte failure) and reduced service is documented.
`53`	Discontinued procedure	Use when testing was started but discontinued due to specimen inability or preanalytic failure before results could be reported.
`59`	Distinct procedural service	Use when billing multiple distinct laboratory genomic services on the same date that are not bundled by payer rules (verify payer bundling policies before application).
`90`	Reference (outside) laboratory	Use when the ordering provider indicates testing performed by an outside laboratory in coordination with the Mayo Clinic assay (subject to payer rules for PLA codes).
`91`	Repeat clinical diagnostic laboratory test	Use when the same family member comparator test is repeated for confirmation within a timeframe acceptable to payers.
`96`	Habilitative services	Rarely used; apply only if payer requires distinction for habilitative vs rehabilitative laboratory reporting (verify payer policy).
`RT`	Right side	Not typically applicable to genomic testing; included for completeness when paired laterality modifiers are required by payer (rare).
`LT`	Left side	Not typically applicable to genomic testing; included for completeness when paired laterality modifiers are required by payer (rare).

Taxonomy Code	Specialty	Notes
207Q00000X	Medical Genetics	Clinical geneticists ordering and interpreting rWGS and family comparator analysis.
2080P0208X	Pediatrics	Neonatologists and pediatric hospitalists caring for critically ill infants who prompt rapid testing.
2085R0202X	Pathology	Molecular genetic pathologists overseeing laboratory testing, validation, and final reports.
363L00000X	Clinical Laboratory	Laboratory directors and genetic testing laboratory personnel managing specimen processing and analysis.
2086S0102X	Pediatric Neurology	Pediatric neurologists involved when early-onset seizures or neurodevelopmental regression prompt rapid genomic sequencing.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`P91.9`	Neonatal encephalopathy, unspecified	Rapid genomic sequencing is used in neonates with unexplained encephalopathy to identify genetic causes.
`G40.8`	Other epilepsy and recurrent seizures	Early-onset refractory seizures often prompt rapid genomic evaluation to find actionable genetic etiologies.
`P28.5`	Other respiratory distress of newborn	Severe multisystem presentations may include respiratory failure where rapid diagnosis can guide care.
`E88.0`	Inborn errors of metabolism, not elsewhere classified	Suspected metabolic disorders are a common indication for rapid genomic testing in infants.
`Q87.8`	Other specified congenital malformation syndromes affecting multiple systems	Syndromic presentations with multiple anomalies prompt comprehensive genomic evaluation.
`R62.0`	Delayed milestone in childhood	Early neurodevelopmental regression or delay can trigger expedited genomic testing in infants and young children.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`0583U`	Rapid Genome Sequencing Family Member Comparator (Mayo Clinic)	Primary PLA code for the family member comparator analysis used alongside proband rapid genome sequencing to determine inheritance and aid variant interpretation.
`81415`	Exome sequencing, proband only (includes interpretation and report)	Common complementary test if exome sequencing is chosen for the proband instead of or prior to whole genome sequencing; not specific to Mayo Clinic PLA.
`81425`	Genome sequencing, interpretation and report (when reported for proband)	Related genomic sequencing procedure for the proband; comparator testing (`0583U`) is billed in addition to the proband sequencing when performed.
`81479`	Unlisted molecular pathology procedure	Used rarely when a specific proprietary PLA is not available to the payer and an unlisted code is required; payer approval often needed.
`88240`	Chromosome analysis, less than 20 cells	Cytogenetic testing that may be performed earlier in diagnostic workflows for some congenital anomalies; not a substitute for genomic sequencing but may be ordered alongside other genetic tests.