CPT 81284 FXN Gene Test Reimbursement

CPT code 81284 identifies a laboratory molecular test for detecting changes in the frataxin gene (FXN), commonly used to identify expanded alleles linked to Friedreich ataxia. Nationally, genetic tests like this are clinically significant for diagnostic confirmation, carrier testing, and family counseling, and they carry implications for coverage policies, prior authorization workflows, and laboratory service billing.

Key payers addressed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context for FXN testing, typical sites of service, common billing modifiers associated with laboratory technical and professional components, and payer coverage patterns where publicly available. The publication outlines common service line placement for molecular diagnostics, benchmarking considerations for reimbursement, and policy or coding updates that affect billing and claims adjudication for genetic testing.

This resource helps coding professionals, laboratory managers, and policy teams understand how CPT code 81284 is used in clinical practice, what stakeholders typically review for medical necessity, and where to look for payer-specific requirements. Data not available in the input is noted where applicable.

Billing Code Overview

CPT code 81284 describes a laboratory molecular diagnostic test that detects changes in the frataxin gene (FXN), typically to identify expanded allele sequences associated with Friedreich ataxia. The procedure represents the technical laboratory analysis of DNA to determine the presence of abnormal FXN alleles.

Service type: Genetic molecular diagnostic testing (laboratory technical component)

Typical site of service: Clinical laboratory or independent diagnostic testing facility (IDTF)

Clinical Context

A 28-year-old patient with progressive gait instability, limb weakness, and a family history of autosomal recessive neurodegenerative disease is referred by a neurologist for genetic testing to confirm suspected Friedreich ataxia. Blood is collected in the clinic or an outpatient phlebotomy setting and sent to a molecular diagnostics laboratory. The lab performs DNA extraction, then a targeted assay to detect expanded GAA trinucleotide repeats in the frataxin gene (FXN) to identify pathogenic alleles. Results are reported to the ordering provider and genetic counselor for diagnostic confirmation, family counseling, and management planning. Typical site of service is an outpatient laboratory or hospital-based molecular diagnostics laboratory; specimen collection occurs in an ambulatory clinic, neurology office, or hospital inpatient unit.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when billing only the professional interpretation or reporting component if separated from the technical lab processing.
`TC`	Technical component	Use when billing only the technical component (laboratory processing and equipment) without professional interpretation.

Taxonomy Code	Specialty	Notes
207RG0100X	Neurology	Neurologists commonly order FXN testing for patients with progressive ataxia and neuropathy.
208Z00000X	Medical Genetics	Medical geneticists interpret and coordinate genetic testing, diagnosis, and family counseling.
208000000X	Pathology	Molecular pathology/laboratory directors oversee testing methodology, quality, and reporting.
207Q00000X	Pediatric Neurology	Pediatric neurologists order FXN testing when symptoms present in children or adolescents.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`G11.1`	Early-onset cerebellar ataxia	Frequent clinical indication for FXN testing when progressive ataxia presents in younger patients.
`G11.3`	Other hereditary ataxias	Directly relevant as Friedreich ataxia is a hereditary ataxia diagnosed by FXN testing.
`G60.0`	Hereditary motor and sensory neuropathy	Peripheral neuropathy accompanies Friedreich ataxia and may prompt genetic testing.
`R26.89`	Other abnormalities of gait and mobility	Non-specific gait disturbance that often triggers neurologic evaluation and genetic testing.
`Z13.79`	Encounter for other screening for genetic and chromosomal anomalies	Used for asymptomatic family testing or cascade screening in relatives of affected individuals.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`81284`	Detection of expanded GAA trinucleotide repeat in the frataxin gene (FXN) (e.g., Friedreich ataxia)	Primary molecular diagnostic assay to detect pathogenic expansions in FXN; the core billed test.
`81225`	SMN1 (survival motor neuron 1) gene analysis; detection of deletions/duplications	Commonly ordered in differential diagnosis of hereditary ataxia and neuromuscular weakness to evaluate spinal muscular atrophy in overlapping presentations.
`81291`	HFE gene analysis, common variants (hemochromatosis)	Ordered in differential workups for systemic causes of neuromuscular symptoms or metabolic contributors when clinically indicated.
`81292`	HFE sequencing full gene analysis	More comprehensive hemochromatosis testing when indicated after initial screens.
`81479`	Unlisted molecular pathology procedure	Used when a specific specialized molecular assay related to FXN is performed that lacks a dedicated CPT code (billing requires documentation).

OpenPayer

Summary & Overview

CPT 81284: Frataxin (FXN) Gene Expansion Detection