Parasomnia in conditions classified elsewhere

This code identifies parasomnias that are secondary to, or a manifestation of, another underlying medical or psychiatric condition. These are undesirable physical events or experiences that occur during sleep, specific sleep stages, or sleep-wake transitions, and are directly attributable to a co-existing disorder. Examples include sleepwalking or nightmares occurring as a symptom of a neurological disease or substance-related disorder.

Use this code when documentation clearly links a parasomnia to an underlying medical, neurological, or psychiatric condition that is coded elsewhere. This code requires a primary diagnosis for the underlying condition. Supporting documentation should detail the specific parasomnia and explicitly state its relationship to the other classified condition.

• Always sequence the underlying condition first, followed by this code.
• Do not use this code for primary parasomnias (e.g., idiopathic sleepwalking, nightmare disorder) not linked to another condition.
• Ensure the medical record explicitly states the "in conditions classified elsewhere" relationship, rather than just co-occurrence.