Circadian rhythm sleep disorder, free running type

This code describes a chronic circadian rhythm sleep disorder characterized by a progressive, non-entrained sleep-wake cycle that is longer than 24 hours. Individuals with this condition experience a daily delay in their sleep and wake times, leading to a recurring pattern of insomnia and excessive daytime sleepiness as their internal clock drifts out of sync with the 24-hour light-dark cycle. It is most commonly seen in blind individuals.

Use this code when documentation clearly indicates a diagnosis of free-running type circadian rhythm sleep disorder, often confirmed through sleep diaries, actigraphy, or polysomnography. This applies to patients whose sleep-wake cycle consistently advances or delays, failing to entrain to environmental cues. Supporting documentation should detail the patient's persistent inability to maintain a stable 24-hour sleep-wake rhythm.

• Differentiate from other circadian rhythm disorders like jet lag disorder (G47.21) or shift work disorder (G47.26) which have distinct etiologies and patterns.
• Ensure the documentation specifies "free-running type" to accurately assign this code.
• Consider co-occurring conditions such as blindness (H54.x) which are frequently associated with this disorder.