Poisoning by oth drug/meds/biol subst, undetermined, sequela

This code signifies a long-term health condition or complication resulting from a past, unspecified poisoning event involving drugs, medications, or biological substances. The original poisoning's intent (accidental, intentional self-harm, assault) could not be determined at the time of the acute event. The patient is now presenting for treatment of a residual effect directly attributable to that past poisoning.

Apply this code when a patient is being treated for a chronic or permanent condition (e.g., organ damage, neurological deficits, persistent mental health issues) that is a direct consequence of a prior poisoning by a drug, medicament, or biological substance, and the intent of the original poisoning was never established. This code is used for subsequent encounters after the acute phase of the poisoning has resolved.

• Always sequence this code after the code(s) for the specific sequela being treated.
• Ensure documentation clearly links the current condition to a past, undetermined poisoning event.
• Do not use for acute poisoning events; this code is exclusively for sequelae.