T40.3X4A
✓ BillablePoisoning by methadone, undetermined, initial encounter
Injury, poisoning and certain other consequences of external causes (S00-T88)
⚠️ Excludes2
inheritedRules inherited from parent codes.
- • drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.-F19.-)
Clinical Description
ICD-10-CM code T40.3X4A represents poisoning by methadone, undetermined, initial encounter. This code falls under the Injury, poisoning and certain other consequences of external causes (S00-T88) classification. It is a billable/specific code valid for HIPAA-covered transactions as of October 1, 2025 (FY2026). This code can be used to indicate a diagnosis for reimbursement purposes on insurance claims.
This is a 8-character code at the 7th level of specificity. This is the most specific code available in this subcategory.
Frequently Asked Questions
What is ICD-10 code T40.3X4A?
ICD-10-CM code T40.3X4A is "Poisoning by methadone, undetermined, initial encounter". It belongs to the category: Injury, poisoning and certain other consequences of external causes (S00-T88).
Is T40.3X4A a billable ICD-10 code?
Yes, T40.3X4A is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
Can T40.3X4A be coded with other codes?
T40.3X4A has 1 Excludes2 note(s). These conditions can be coded together if both are documented in the patient record.
Related Codes in T40.3X4
Other codes in the same category that may be relevant for differential coding:
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Data Source
CMS ICD-10-CM 2026 Tabular List
Updated October 1, 2025 (FY2026)