Summary & Overview
CPT 88264: Chromosome Analysis with Karyotype, 20–25 Cells
CPT code 88264 represents a detailed cytogenetic chromosome analysis that includes counting chromosomes and preparing karyotypes for 20 to 25 cells. This test is used to detect aneuploidy and structural chromosomal abnormalities relevant to prenatal diagnosis, infertility workups, hematologic malignancies, and constitutional genetic evaluations. Nationally, chromosome analysis remains a core diagnostic service in clinical genetics and pathology laboratories, with implications for diagnosis, patient counseling, and downstream care pathways.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find national-level context on the clinical purpose of the procedure, typical sites of service, common billing modifiers, and how this code fits into laboratory service lines. The publication outlines benchmarking considerations, coding relationships, and administrative elements that affect claims submission and reimbursement workflows. Where specific payer policy details or utilization metrics are unavailable in the input, the text notes that Data not available in the input. The goal is to provide a concise operational and policy-oriented overview for billing, compliance, and laboratory management audiences.
Billing Code Overview
CPT code 88264 describes a chromosome analysis in which the analyst examines and counts chromosomes in 20 to 25 cells and prepares a karyotype for each cell examined. This service is a cytogenetic laboratory procedure used to assess chromosomal number and structural integrity for diagnostic and clinical management purposes.
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Service type: Cytogenetic chromosome analysis
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Typical site of service: Clinical laboratory or hospital laboratory performing cytogenetic testing
Clinical & Coding Specifications
Clinical Context
A patient, typically an adult or pediatric individual referred from genetics, hematology, obstetrics, or oncology, presents for chromosome analysis (karyotype) to evaluate suspected chromosomal abnormalities. Common clinical scenarios include: prenatal evaluation for abnormal ultrasound or positive screening, assessment of developmental delay or congenital anomalies in a child, investigation of infertility or recurrent pregnancy loss in adults, and characterization of hematologic malignancies (e.g., leukemia) where cytogenetic abnormalities guide prognosis and treatment. The clinical workflow begins with specimen collection (peripheral blood, amniotic fluid, chorionic villus sampling, bone marrow) and accessioning in the cytogenetics laboratory. The analyst cultures cells as required, harvests and prepares metaphase spreads, stains them, and analyzes 20–25 cells for chromosome counts and structural abnormalities. A karyotype is prepared for each examined cell and a report is issued with interpretation by a cytogeneticist. Results are routed to the ordering clinician and incorporated into patient management, counseling, and possible further molecular testing.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional (interpretation) portion of the cytogenetic service performed by the laboratory director or pathologist. |
TC | Technical component | Use when billing only the technical portion (laboratory processing, culture, slide preparation) of the service. |
59 | Distinct procedural service | Use when a separate, distinct cytogenetic procedure is performed in the same session that is not normally billed together. |
90 | Reference (outside) laboratory | Use when the test was performed by an outside reference laboratory and an outside lab performed the analysis. |
91 | Repeat clinical diagnostic laboratory test | Use when the test is a repeated analysis on the same specimen to confirm prior results (repeat testing). |
90 | Reference (outside) laboratory | Use when the service was performed by an external laboratory (billing lab reports reference lab). |
76 Not applicable | Data not available in the input. | Data not available in the input. |
22 | Increased procedural services | Use when the cytogenetic analysis required substantially greater resources or complexity than usual. |
52 | Reduced services | Use when the test is partially reduced or not fully performed (e.g., culture fails, partial analysis). |
53 | Discontinued procedure | Use when the testing process was started but discontinued for reasons outside the provider’s control (e.g., specimen contamination). |
90 | Reference (outside) laboratory | Use when testing performed by another laboratory; provider reports reference lab involvement. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 207RG0100X | Anatomic and Clinical Pathology | Pathologists oversee cytogenetic interpretation and reporting. |
| 2080P0002X | Medical Genetics | Clinical geneticists order and interpret karyotype results for inherited conditions. |
| 207U00000X | Clinical Cytogenetics Laboratory | Cytogeneticists and laboratory directors responsible for technical and interpretive services. |
| 207K00000X | Hematology & Oncology | Hematologists/oncologists order cytogenetics for malignancy diagnosis and prognosis. |
| 261Q00000X | Obstetrics & Gynecology | OB/GYNs order prenatal cytogenetic testing for fetal anomaly evaluation. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
Q90.9 | Down syndrome, unspecified | Karyotype is used to confirm trisomy 21 and characterize chromosomal origin. |
Q93.9 | Chromosomal abnormality, unspecified | General indication for diagnostic chromosome analysis when a chromosomal abnormality is suspected. |
R62.0 | Delayed milestone in childhood | Developmental delay often prompts chromosomal analysis to identify underlying genetic causes. |
N97.9 | Female infertility, unspecified | Cytogenetic testing is used in infertility workups to detect balanced translocations or sex chromosome abnormalities. |
O03.9 | Spontaneous abortion, incomplete/unspecified | Products of conception may undergo karyotype to determine chromosomal causes of pregnancy loss. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
88262 | Chromosome analysis, single cell analysis (e.g., high-resolution), analysis of one cell | May be used for limited or single-cell analyses when fewer cells are evaluated; sometimes billed in conjunction for specialized analyses. |
88271 | FISH, each probe; qualitative or quantitative (single probe) | Fluorescence in situ hybridization is commonly performed after abnormal karyotype or to target specific chromosomal regions for confirmation. |
88265 | Cytogenomic constitutional microarray analysis | Microarray testing is often ordered following or instead of karyotype for higher-resolution detection of copy number variants. |
88267 | Cytogenetic analysis requiring interpretation by a physician (e.g., culture and analysis of additional cells) | Used for extended or supplemental cytogenetic interpretive services beyond standard cell counts. |
88399 | Unlisted pathology procedure | Used when a specific cytogenetic-related procedure does not have an assigned CPT code (rarely used). |