CurrentCapital BlueCrossPolicy MP 2.234

Cytochrome P450 Genotype Guided Treatment Strategy

Capital BlueCross clinical policy MP 2.234 defines medical necessity and investigational indications for cytochrome P450 (CYP450) genotyping to guide drug selection or dosing, including specific guidance for CYP2D6, CYP2C9, and CYP2C19 testing and a statement that multi-gene CYP450 panels are investigational. Applies to Capital BlueCross-administered products (with product variations noted).

Policy Summary

PayerCapital BlueCross

PolicyCytochrome P450 Genotype Guided Treatment Strategy

Policy CodePolicy MP 2.234

Change TypeAdministrative coding and reference updates

Effective DateOct 1, 2025

Next Review Date

Key ActionSubmit documentation of the specific clinical indication and genotype results when requesting coverage for CYP2D6, CYP2C9, or CYP2C19 testing to support medical necessity.

SourceLink

POLICY UPDATE CHANGES

Policy statement unchanged across multiple reviews; background, references and coding periodically updated and new CPT/HCPCS codes added or deleted as administrative updates.

3Specific CYP genes with named medically necessary uses (CYP2D6, CYP2C9, CYP2C19)

MultipleICD-10 diagnosis codes listed as covered when medically necessary

ManyCPT/Proprietary molecular procedure codes listed as investigational (not covered)

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Medically Necessary and Not Covered Indications

Medically Necessary

CYP450 genotyping may be considered medically necessary for the following specific drug–indication pairs:

ANY of the following

CYP2D6 genotyping for members with Gaucher disease being considered for treatment with eliglustatdosing determined by CYP2D6 metabolizer status (see policy guidelines)
CYP2D6 genotyping for members with Huntington disease being considered for treatment with tetrabenazinerequired if planned dose > 50 mg/day; for CYP2D6 poor metabolizers max daily dose = 50 mg and max single dose = 25 mg
CYP2C9 genotyping for members with relapsing forms of multiple sclerosis being considered for treatment with siponimod (Mayzent)standard maintenance 2 mg; use 1 mg maintenance for CYP2C9 *1/*3 or *2/*3; contraindicated in CYP2C9 *3/*3
CYP2C19 genotyping to aid choice of clopidogrel (Plavix) versus alternative antiplatelet agents for select members in high-risk clinical scenarios (see policy guidelines)

Investigational / Not Covered

CYP450 genotyping is considered investigational (insufficient evidence of net health benefit) for the following indications and testing approaches:

ALL of the following

Selection or dosing of codeine
Dosing of efavirenz and other antiretroviral therapies for HIV infection
Dosing of immunosuppressants for organ transplantation
Selection or dosing of β-blockers (e.g., metoprolol)
Dosing and management of antitubercular medications

Policy Guidelines / Conditional Use

Situations where testing may be reasonable/considered but is restricted by context or guideline recommendations:

ALL of the following

CYP2C19 testing is not recommended routinely for clopidogrel use in stable CAD but may be considered in select high-risk ACS/PCI patients (e.g., urgent PCI for ACS, elective PCI for unprotected left main disease, last patent vessel PCI, complex lesions, prior stent thrombosis)
The policy notes evidence does not support clopidogrel dose escalation based on CYP2C19 genotype
For eliglustat: dosing depends on CYP2D6 metabolizer status; FDA labeling gives specific dosing and notes reduced effectiveness in ultrarapid metabolizers84 mg twice daily for CYP2D6 EMs and IMs; 84 mg once daily for CYP2D6 PMs
For tetrabenazine: patients requiring >50 mg/day should be CYP2D6 genotyped; PMs should not exceed 50 mg/day (max single dose 25 mg)

Relevant CPT/HCPCS/ICD-10 Codes

Covered when medically necessary - CPT/Proprietary molecularmixedCovered

81226	CYP2C19 genotyping
81227	CYP2D6 genotyping

Covered when medically necessary - ICD-10 diagnoses (examples provided)ICD-10Covered

E75.22	Gaucher disease
E75.27	Pelizaeus-Merzbacher disease
G10	Huntington's disease
G35	Multiple sclerosis
G35A	Relapsing-remitting multiple sclerosis
G35B	Primary progressive multiple sclerosis
G35B0	Primary progressive multiple sclerosis, unspecified
G35B1	Active primary progressive multiple sclerosis
G35B2	Non-active primary progressive multiple sclerosis
G35C	Secondary progressive multiple sclerosis

1–10 of 17

1/2

Covered when medically necessary - CPT (additional)CPTCovered

81225

CYP2C9 genotyping (listed in policy as covered when medically necessary for diagnoses in Table 2)

Covered for cardiology-related diagnoses (ICD-10 Table 2 examples)ICD-10Covered

I20.0	Unstable angina
I20.1	Angina pectoris with documented spasm
I20.81	Angina pectoris with coronary microvascular dysfunction
I20.89	Other forms of angina pectoris
I20.9	Angina pectoris, unspecified
I21.01	STEMI involving the left main coronary artery
I21.02	STEMI involving left anterior descending coronary artery
I21.09	STEMI involving other coronary artery of anterior wall
I21.11	STEMI involving right coronary artery
I21.19	STEMI involving other artery of inferior wall

1–10 of 24

1/3

Investigational / Not Covered - Procedure codesmixedNot Covered

0434U	Proprietary molecular procedure code listed as investigational
0438U	Proprietary molecular procedure code listed as investigational
0461U	Proprietary molecular procedure code listed as investigational
0516U	Proprietary molecular procedure code listed as investigational
0533U	Proprietary molecular procedure code listed as investigational
81230	Molecular/genetic procedure code listed as investigational
81231	Molecular/genetic procedure code listed as investigational
81418	Molecular/genetic procedure code listed as investigational
0392U	Proprietary molecular procedure code listed as investigational

Procedure / Proprietary Codes mentioned in revision historymixed

81418	Added effective 01/01/2023 (no additional detail in this part)
0380U	Added 04/01/2023; later deleted effective 01/01/2025
0392U	Added effective 07/01/2023
0434U	Added as INV, effective 01/01/2024
0438U	Added as INV, effective 01/01/2024
0461U	Added effective 07/01/2024
0516U	Added effective 10/01/2024
0533U	Added effective 04/01/2025

Prior Authorization, Documentation, and Billing Rules

Prior Authorization

Medical necessity required for coverage

CYP2D6, CYP2C9, and CYP2C19 genotyping are covered only when the specific medical necessity criteria in this policy are met (for example: CYP2D6 testing for eliglustat in Gaucher disease or for tetrabenazine when planned dose >50 mg/day; CYP2C9 testing for siponimod in relapsing MS; CYP2C19 testing in select high‑risk clopidogrel scenarios). Providers must submit documentation supporting the clinical indication for testing to obtain coverage.

81226
81227
81225

Documentation Required

Genotype-based dosing requirements from FDA labeling

When genotyping is used to inform drug dosing or to determine contraindication per FDA labeling (for example eliglustat, tetrabenazine, siponimod), document the genotype results and the metabolizer status (e.g., poor, intermediate, normal/extensive, ultrarapid) that was used to select the dose or to determine that the drug is contraindicated.

Clinical Background

Pharmacogenomics evaluates inherited genetic variation that affects drug metabolism and response. Variants in the cytochrome P450 (CYP450) enzyme family — notably CYP2D6, CYP2C19, CYP2C9, CYP3A5, and CYP2B6 — are common and can substantially alter pharmacokinetics, leading to important differences in drug efficacy and toxicity across patients.

Many CYP450 enzymes are polymorphic, producing predictable clinical metabolizer phenotypes: poor metabolizers (PMs), intermediate metabolizers (IMs), normal/extensive metabolizers (NM/EM), and ultrarapid metabolizers (UMs). These phenotypes influence blood drug or active metabolite concentrations — for example, UMs may not reach therapeutic concentrations for active drugs at usual doses, while PMs can experience increased drug exposure and adverse events; the opposite can occur for prodrugs that require bioactivation by a CYP enzyme.

Genotyping to identify CYP450 metabolizer status can inform drug selection or dosing when the drug has a narrow therapeutic window, when treatment failure or toxicity would be serious, or when alternative agents/doses are available and recommended by labeling or guidelines. Specific examples with explicit genotype-based recommendations in FDA labeling include CYP2D6 testing for eliglustat (Gaucher disease) and for tetrabenazine when planned doses exceed 50 mg/day, and CYP2C9 testing for siponimod (relapsing multiple sclerosis); CYP2C19 status is the most validated predictor of clopidogrel response and may guide agent selection in select high‑risk PCI/ACS scenarios rather than routine testing in stable CAD.

Key Terms

Definitions

GenotypeThe pair of genes present for a particular characteristic or protein.

PolymorphismThe state or quality of existing or occurring in several different forms.

MP 2.234Policy number for Cytochrome P450 genotype-guided treatment strategy (Cytochrome P450 Genotype Guided Treatment Strategy).

Policy Updates

2025-04-01coding update

New proprietary procedure code 0533U added effective 04/01/2025.

2025-01-01coding update

Procedure code 0380U deleted effective 01/01/2025.

2024-10-01coding update

New proprietary procedure code 0516U added effective 10/01/2024.