Late effect of toxic effects of nonmedical substances

This code signifies a health condition that is a residual effect or sequela of a past poisoning or adverse reaction to a nonmedical substance. These are long-term or permanent problems that manifest after the acute phase of the toxic exposure has resolved. Examples include neurological damage, organ dysfunction, or mental health disorders resulting from prior substance abuse or accidental poisoning.

Apply this code when documentation clearly indicates a current condition is a direct consequence of a previous toxic exposure to a nonmedical substance (e.g., illicit drugs, pesticides, industrial chemicals). The patient is no longer experiencing the acute toxic effects, but rather a lasting complication. Supporting documentation should specify the causal link between the past exposure and the current sequela.

• Always sequence this code after the specific condition or manifestation being treated (e.g., chronic hepatitis due to past solvent exposure).
• Do not use for acute toxic effects; those require codes from the 960-989 range.
• Ensure the documentation explicitly states the "late effect" or "sequela" of a nonmedical substance to differentiate from adverse effects of therapeutic drugs.