F51.1
Non-billableHypersomnia not due to a substance or known physiological condition
F51.1 is the ICD-10-CM code for Hypersomnia not due to a substance or known physiological condition. It is a non-billable category code — use a more specific child code such as F51.11 for billing.
F01-F99 Mental, Behavioral and Neurodevelopmental disorders
Hypersomnia is defined as a condition of either excessive daytime sleepiness and sleep attacks (not accounted for by an inadequate amount of sleep) or prolonged transition to the fully aroused state upon awakening. In the absence of an organic factor for the occurrence of hypersomnia, this condition is usually associated with mental disorders.
What this means — in plain language
MedlinePlus · NIHWhat is sleep? While you are sleeping your brain and body functions are still active. Sleep is a natural process that helps your body restore energy, supports learning and memory, and keeps you healthy. It's not just the number of hours of sleep you get that matters. The quality of your sleep is also important. During the night, your brain cycles through different stages of non-rapid eye movement (non-REM) sleep and…
Read more about Sleep Disorders at MedlinePlus ↗Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.
Excludes2 — not included here
- •alcohol related hypersomnia (F10.182, F10.282, F10.982)
- •drug-related hypersomnia (F11.182, F11.282, F11.982, F13.182, F13.282, F13.982, F14.182, F14.282, F14.982, F15.182, F15.282, F15.982, F19.182, F19.282, F19.982)
- •hypersomnia NOS (G47.10)
- •hypersomnia due to known physiological condition (G47.10)
- •idiopathic hypersomnia (G47.11, G47.12)
- •narcolepsy (G47.4-)
Frequently asked questions
Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.
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