Wednesday, November 4, 2026

Code T39.1X1S describes a sequela resulting from an accidental or unintentional poisoning by 4-aminophenol derivatives, most commonly known as acetaminophen or paracetamol. The inclusion of the 7th character 'S' signifies that the patient is suffering from late effects or complications long after the acute toxic event has resolved. When assigning this code, it is critical to sequence the specific late manifestation, such as chronic hepatic failure, as the primary diagnosis. Coders must ensure the acute poisoning episode is no longer active before selecting a sequela code.