CPT 0073U: CYP2D7–2D6 Hybrid Gene Targeted Sequence Analysis

CPT code 0073U designates a proprietary laboratory analysis for the CYP2D7–2D6 Hybrid Gene Targeted Sequence Analysis developed by the Mayo Clinic Laboratory. It is a targeted follow‑up genetic sequencing test performed when the initial 0070U assay does not resolve a patient’s CYP2D6 genotype. This genotype can influence metabolism of multiple commonly prescribed medications, making accurate determination clinically relevant for pharmacogenomic decision‑making nationwide.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will find a concise briefing on the code’s clinical purpose, typical service setting, and where it fits in diagnostic workflows. The publication summarizes payer coverage considerations, common billing modifiers, and implications for laboratory billing operations. It also highlights practical benchmarks and policy context relevant to proprietary laboratory analyses (PLA) codes and molecular diagnostics reimbursement.

This summary is intended for a national audience of laboratory administrators, billing professionals, and clinicians seeking a clear explanation of CPT code 0073U, its clinical role as a follow‑up CYP2D6 genotype test, and the administrative considerations that commonly arise when billing PLA molecular assays.

Billing Code Overview

CPT code 0073U is a Proprietary Laboratory Analyses (PLA) code for the CYP2D7–2D6 Hybrid Gene Targeted Sequence Analysis, developed by the Mayo Clinic Laboratory. This test is a follow‑up molecular diagnostic assay used when the initial 0070U test does not determine a patient’s CYP2D6 genotype, which can affect drug metabolism.

Service type: Follow‑up targeted genetic sequencing / molecular diagnostic test

Typical site of service: Clinical molecular or specialty laboratory

Clinical Context

A 52-year-old patient on chronic opioid therapy for chronic pain is being evaluated after inconsistent clinical response and reported adverse effects when prescribed multiple CYP2D6-metabolized medications. The treating clinician ordered initial targeted pharmacogenomic testing for CYP2D6 using the test represented by code 0070U. The initial assay did not resolve the patient’s CYP2D6 genotype due to a complex hybrid allele suspected between CYP2D6 and CYP2D7. The clinician requests follow-up targeted sequence analysis using the Mayo Clinic Laboratory’s CYP2D7–2D6 Hybrid Gene Targeted Sequence Analysis, reported with 0073U, to clarify the genotype and guide medication selection and dosing.

The clinical workflow: a sample (blood or buccal) is collected at an outpatient phlebotomy site or specialty clinic and sent to the reference laboratory. The laboratory performs targeted sequence analysis focused on detecting CYP2D6/CYP2D7 hybrid alleles. Results are returned to the ordering clinician and incorporated into the patient’s medication management plan, particularly for drugs highly dependent on CYP2D6 metabolism (for example, certain antidepressants, antipsychotics, and opioids). Typical sites of service include outpatient clinic, ambulatory surgery center for specimen collection, or a reference laboratory performing the proprietary test.

Coding Specifications

Modifier	Description	When to Use

Taxonomy Code	Specialty	Notes
`208000000X`	Clinical Pathology	Laboratory directors and clinical pathologists overseeing molecular testing
`207L00000X`	Molecular Genetic Pathology	Specialty focused on molecular diagnostics and interpretation
`2085R0200X`	Medical Genetics	Clinical geneticists who may order or interpret pharmacogenomic testing
`207K00000X`	Clinical Chemistry	Laboratory specialists involved in assay validation and reporting
`363LF0000X`	Pharmacist	Clinical pharmacists who integrate pharmacogenomic results into medication management

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`Z13.79`	Encounter for other screening for genetic and chromosomal anomalies	Used when pharmacogenomic screening is being done proactively to guide therapy
`Z15.09`	Genetic susceptibility to other disease	Applicable when documenting genetic susceptibility affecting drug metabolism
`F32.9`	Major depressive disorder, single episode, unspecified	Antidepressant selection and dosing may be influenced by CYP2D6 genotype
`G47.00`	Insomnia, unspecified	Medications metabolized by CYP2D6 may be considered for treatment; genotype affects dosing and selection
`M54.5`	Low back pain	Chronic pain management often uses opioids metabolized by CYP2D6; genotype may guide opioid selection/dosing
`T40.2X5A`	Poisoning by other opioids, accidental (initial encounter)	Relevant when adverse drug response possibly linked to altered CYP2D6 metabolism is investigated
`Z79.899`	Other long term (current) drug therapy	Used to indicate ongoing medication therapy where pharmacogenomic testing may inform management

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`0070U`	CYP2D6 Copy Number and Variant Analysis, targeted genotyping assay	Often performed prior to `0073U`; `0073U` is the follow-up when `0070U` fails to resolve genotype
`81406`	Pharmacogenomic testing of multiple genes (stacked molecular pathology procedures); targeted sequence analysis, 1-5 genes	Alternative or complementary pharmacogenomic panels that may be ordered in broader assessment of drug metabolism
`81162`	CYP2D6 (cytochrome P450, family 2, subfamily D) (eg, variant analysis)	Related single-gene molecular diagnostic code that may be used for reporting other CYP2D6 assays
`81175`	CYP2C19 gene analysis	Frequently ordered alongside CYP2D6 testing to evaluate metabolism of other drug classes
`0064U`	CYP2D6 Copy Number Variant analysis (example PLA)	Other proprietary CYP2D6-focused PLA tests that may be ordered in the pharmacogenomic workup

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Summary & Overview