Summary & Overview
CPT 0156U: SMASH™ Copy Number Sequence Analysis for Developmental Disorders
CPT code 0156U designates a Proprietary Laboratory Analyses (PLA) test — the SMASH™ assay from New York Genome Center, Marvel Genomics™ — which uses copy number sequence analysis to detect genetic variations associated with physical and mental developmental disorders. As a PLA code, 0156U is specific to a single commercial test and signals unique clinical utility in genetic diagnostics for developmental delay and related phenotypes. Nationally, PLA codes have implications for coverage policy, coding clarity, and lab reimbursement pathways because they identify single-vendor assays rather than broad method classes.
Key payers considered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find concise context on the clinical purpose of the test, the laboratory service setting, and typical use cases in developmental genetics. The publication provides benchmarking information where available, summarizes payer coverage posture and trends for PLA tests, and outlines billing and coding considerations specific to single-source genomic assays. The report is intended to inform coding staff, laboratory billing teams, and policy analysts about the role of CPT code 0156U in current clinical and payer landscapes.
Billing Code Overview
CPT code 0156U is a Proprietary Laboratory Analyses (PLA) code that applies to a single, manufacturer-specific laboratory test. Report CPT code 0156U for the SMASH™ test from New York Genome Center, Marvel Genomics™, which uses copy number sequence analysis to detect genetic variations associated with physical and mental developmental disorders.
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Service type: Clinical genomic laboratory testing using copy number sequence analysis to identify genetic variations linked to developmental disorders
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Typical site of service: Clinical laboratory or reference laboratory setting
Clinical & Coding Specifications
Clinical Context
A pediatric or pediatric-adolescent patient presents to a genetics clinic or neurodevelopmental specialty clinic because of global developmental delay, intellectual disability, autism spectrum disorder, congenital anomalies, or unexplained developmental regression. The referring clinician (pediatrician, pediatric neurologist, clinical geneticist) documents a detailed history, family history, and physical exam noting dysmorphic features or neurologic findings. After initial metabolic, imaging, and chromosomal microarray or targeted testing are considered, the clinician orders the SMASH™ test (0156U) from New York Genome Center, Marvel Genomics™ to perform copy-number sequence analysis for detection of submicroscopic deletions, duplications, and other copy-number variants associated with physical and mental developmental disorders.
Specimen collection is typically peripheral blood drawn in an outpatient clinic, hospital outpatient phlebotomy, or inpatient pediatric unit. The sample is sent to the performing laboratory with accompanying clinical documentation and the appropriate order form. The laboratory performs next-generation sequencing–based copy number analysis, interprets detected variants against established databases and clinical guidelines, and returns a report including pathogenic, likely pathogenic, and variants of uncertain significance relevant to developmental disorders. Results are reviewed by the ordering clinician and genetic counseling is provided when actionable findings are reported. Billing uses the PLA code 0156U for the proprietary SMASH™ test.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
TC | Technical component | Use when billing only the laboratory or technical portion of the test (facility or performing laboratory). |
26 | Professional component | Use when billing only the professional component (interpretation and report) if separated between entities. |
59 | Data not provided in the input. | Data not available in the input. |
52 | Reduced services | Use when the test is partially performed or a limited analysis is completed compared with the full test. |
53 | Discontinued procedure | Use when specimen was collected but testing discontinued prior to completion for patient or technical reasons. |
AD | Physician assistant as billing provider | Use when a physician assistant billable service is relevant to specimen collection or ordering in states where applicable. |
QK | Ordered but not performed by the billing laboratory | Use when the performing laboratory subcontracted the test and another lab performed the analysis. |
QX | Ordering clinician performed part of the service | Use when the ordering practitioner performed the professional component in a split-billing arrangement. |
FY | Out-of-area laboratory test | Use when the test is performed by a lab outside normal payer network or jurisdiction (payer-specific use). |
CO | Routine care covered by workers' compensation | Use when the test is related to a workers' compensation claim and payer-specific reporting is required. |
SH | Physician assistant -- supervising physician not present | Use where applicable to indicate scope of supervision for the billing practitioner. |
SJ | Unusual services or supplies | Use to indicate unexpected supplies or services required to complete the test. |
TG | Technical component performed at an alternate site | Use when the technical processing occurs at a different facility location than usual. |
QY | Ordering physician performed noninterpretive services | Use when ordering physician provided specimen handling or noninterpretive activities tied to the test. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 207Q00000X | Clinical Genetics | Clinical geneticists order, interpret, and communicate results for genomic copy-number testing. |
| 207RH0000X | Pediatric Medicine | Pediatricians and pediatric neurologists frequently initiate testing for developmental delay and congenital anomalies. |
| 2080P0208X | Pathology - Molecular Genetic Pathology | Laboratory directors and molecular pathologists oversee test validation and result interpretation. |
| 363L00000X | Nurse Practitioner | Nurse practitioners in genetics and pediatrics coordinate testing and counseling. |
| 367A00000X | Physician Assistant | Physician assistants in specialty clinics assist with ordering and result communication. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
F84.0 | Autism spectrum disorder | ASD patients often undergo genetic testing for copy-number variants associated with neurodevelopmental phenotypes. |
F79 | Intellectual developmental disorder, unspecified | Unexplained intellectual disability prompts copy-number analysis to identify etiologic CNVs. |
R62.0 | Delayed milestone in childhood | Developmental milestone delays lead to genomic evaluation including CNV testing. |
Q87.8 | Other specified congenital malformation syndromes affecting multiple systems | Syndromic presentations with congenital anomalies warrant copy-number sequence analysis. |
G40.909 | Epilepsy, unspecified, not intractable, without status epilepticus | Seizure disorders in children can be associated with CNVs; testing may clarify genetic etiology. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
81479 | Unlisted molecular pathology procedure | Used when a specific molecular test lacks a covered code; occasionally referenced before PLA codes were established. |
81229 | Chromosome microarray analysis (CMA), copy number variant detection by microarray | Alternative or complementary test for genome-wide copy-number variant detection; may be ordered prior to or alongside the SMASH™ test. |
81415 | Exome sequencing, interpretation and report (when performed) | Broader sequencing analysis that may be performed if copy-number sequencing is nondiagnostic or if single-nucleotide variant analysis is needed in addition to CNV detection. |
96372 | Therapeutic, prophylactic, or diagnostic injection | May be billed separately if intravenous contrast or sedation medications are administered during an associated imaging procedure; not billed for the lab test itself. |
36415 | Collection of venous blood by venipuncture | Billed for specimen collection in outpatient or inpatient settings when separately reportable. |