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ICD-10-CM · FY 2026 APRIL UPDATE

T40.3

Poisoning by, adverse effect of and underdosing of methadone

Diagnosis reference

Nonbillable category

This entry is a category or subcategory. Choose the appropriate billable descendant based on the clinical documentation.

Effective periodOctober 1, 2026–September 30, 2027
SourceCMS ICD-10-CM order file
ClassificationDiagnosis · clinical modification

Related entries

Up to 30 descendants in this category

CODEDESCRIPTIONTYPE
T40.3XPoisoning by, adverse effect of and underdosing of methadoneCategory
T40.3X1Poisoning by methadone, accidental (unintentional)Category
T40.3X1APoisoning by methadone, accidental (unintentional), initial encounterBillable
T40.3X1DPoisoning by methadone, accidental (unintentional), subsequent encounterBillable
T40.3X1SPoisoning by methadone, accidental (unintentional), sequelaBillable
T40.3X2Poisoning by methadone, intentional self-harmCategory
T40.3X2APoisoning by methadone, intentional self-harm, initial encounterBillable
T40.3X2DPoisoning by methadone, intentional self-harm, subsequent encounterBillable
T40.3X2SPoisoning by methadone, intentional self-harm, sequelaBillable
T40.3X3Poisoning by methadone, assaultCategory
T40.3X3APoisoning by methadone, assault, initial encounterBillable
T40.3X3DPoisoning by methadone, assault, subsequent encounterBillable
T40.3X3SPoisoning by methadone, assault, sequelaBillable
T40.3X4Poisoning by methadone, undeterminedCategory
T40.3X4APoisoning by methadone, undetermined, initial encounterBillable
T40.3X4DPoisoning by methadone, undetermined, subsequent encounterBillable
T40.3X4SPoisoning by methadone, undetermined, sequelaBillable
T40.3X5Adverse effect of methadoneCategory
T40.3X5AAdverse effect of methadone, initial encounterBillable
T40.3X5DAdverse effect of methadone, subsequent encounterBillable
T40.3X5SAdverse effect of methadone, sequelaBillable
T40.3X6Underdosing of methadoneCategory
T40.3X6AUnderdosing of methadone, initial encounterBillable
T40.3X6DUnderdosing of methadone, subsequent encounterBillable
T40.3X6SUnderdosing of methadone, sequelaBillable

Use the complete reference

This reference does not reproduce the full tabular hierarchy, inclusion notes, Excludes1/2 notes, sequencing instructions, or seventh-character rules. Review the official tables and coding guidelines.

Open official CMS files

ICD-10-CM codes describe diagnoses. They do not have an independent Medicare PFS reimbursement amount, and billability alone does not establish coverage.