Billable / Specific Code
ICD-10-CM T43.021 is the diagnosis code for Poisoning by tetracyclic antidepressants, accidental (unintentional). This code falls under the section "Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances" within Chapter 19 — Injury, poisoning and certain other consequences of external causes (S00-T88). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
Understanding where T43.021 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, T43.021 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
T43.021 is the ICD-10-CM diagnosis code for "Poisoning by tetracyclic antidepressants, accidental (unintentional)". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of T43.021 is T43.02 ("Poisoning by, adverse effect of and underdosing of tetracyclic antidepressants"). T43.021 provides a more specific classification within this category.
T43.021 is located in Section T36-T50 — "Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances" within Chapter 19 of the ICD-10-CM Tabular List.
Use T43.021 when the patients documented diagnosis matches "Poisoning by tetracyclic antidepressants, accidental (unintentional)" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Poisoning by tetracyclic antidepressants, accidental (unintentional) is T43.021.
Yes, T43.021 can be used as a primary diagnosis code since it is billable and specific.
T43.021 is in Chapter 19 of the ICD-10-CM Tabular List.
Yes, T43.021 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.