F51.1
Hypersomnia not due to a substance or known physiological condition
Not billable — category only FY2026 2025-10-01 → 2026-09-30
Exclusions 8 never code together
F51.1code
Excludes2
- alcohol related hypersomnia (F10.182, F10.282, F10.982)F10.182F10.182F10.282F10.282F10.982F10.982
- 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)F11.182F11.182F11.282F11.282F11.982F11.982F13.182F13.182F13.282F13.282F13.982F13.982F14.182F14.182F14.282F14.282F14.982F14.982F15.182F15.182F15.282F15.282F15.982F15.982F19.182F19.182F19.282F19.282F19.982F19.982
- hypersomnia NOS (G47.10)G47.10G47.10
- hypersomnia due to known physiological condition (G47.10)G47.10G47.10
- idiopathic hypersomnia (G47.11, G47.12)G47.11G47.11G47.12G47.12
- narcolepsy (G47.4-)G47.4-G47.4-
F01-F99chapter
Excludes2
- symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)R00-R99
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 1
F01-F99chapter
Includes
- disorders of psychological development
Index entries leading here filed at null
No alphabetic index entry points at this code.
Alongside this code 6 same parent — F51
Subordinate codes 4
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.