Summary & Overview
CPT 88289: Additional High-Resolution Chromosome Analysis
CPT code 88289 represents an additional high-resolution chromosome analysis performed by a cytogenetics analyst to visualize chromosomal features too small for routine analysis. This supplemental cytogenetic study enhances detection of subtle structural abnormalities and can affect diagnostic and management decisions in genetics, oncology, prenatal, and pediatric contexts. Nationally, high-resolution cytogenetic testing remains an important adjunct to standard karyotyping and molecular methods for specific clinical indications.
Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical purpose of this service, expected sites of service, and the common billing context for laboratories and hospital-based cytogenetics programs. The publication summarizes benchmark considerations for coverage and coding, typical documentation elements that support medical necessity, and how this procedure fits alongside other cytogenetic and molecular diagnostic services. Data not available in the input will be noted where applicable. The content is intended for national audiences including billing managers, laboratory directors, and policy analysts who need concise context about CPT code 88289 and its clinical billing implications.
Billing Code Overview
CPT code 88289 describes an additional high-resolution chromosome analysis performed by a cytogenetics analyst. This service involves a more detailed examination of chromosomes to detect structural features and abnormalities that are too small to be seen during routine chromosome analysis. The procedure is an extension of standard cytogenetic testing intended to increase diagnostic sensitivity for chromosomal abnormalities.
Service type: High-resolution cytogenetic study / Chromosome analysis (additional high resolution study)
Typical site of service: Clinical cytogenetics laboratory or hospital laboratory
Clinical & Coding Specifications
Clinical Context
A patient is referred to a clinical cytogenetics laboratory after an abnormal prenatal screening or a postnatal evaluation for congenital anomalies, developmental delay, or multiple congenital malformations. The ordering clinician (maternal-fetal medicine specialist, neonatologist, pediatric geneticist, or clinical geneticist) requests a high-resolution chromosome study because routine karyotype at standard resolution was nondiagnostic or subtle structural abnormalities are suspected. Typical workflow: specimen collection (amniotic fluid, chorionic villus sample, peripheral blood, or bone marrow) is sent to the cytogenetics lab; cultures are established when required; a routine chromosome analysis is performed first. If routine analysis appears normal but clinical suspicion remains (for example, unexplained multiple congenital anomalies, growth restriction, intellectual disability, or abnormal first-trimester screen), the laboratory analyst performs an additional high-resolution study (88289) to detect smaller banding differences and submicroscopic structural changes not visible on routine analysis. Results are interpreted by the laboratory director or clinical cytogeneticist and reported to the ordering provider, with genetic counseling offered when clinically indicated. Typical site of service: hospital-based cytogenetics laboratory, independent reference cytogenetics laboratory, or academic medical center; specimen collection may occur in outpatient clinic, ambulatory surgery center, inpatient unit, or prenatal diagnostic center. Typical patient scenario: a 28-week fetus with ultrasound-detected cardiac and renal anomalies after normal routine karyotype, or a child with unexplained developmental delay where routine cytogenetics was nondiagnostic and high-resolution analysis is indicated.
Coding Specifications
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