F51.1

ICD-10Non-billable category

Hypersomnia not due to a substance or known physiol cond

Official ICD-10-CM descriptor (FY2026)

Hypersomnia not due to a substance or known physiological condition

F51.1 is a category heading, not a billable code. CMS does not accept it on a claim; report one of the more specific codes beneath it.

Excludes2

Not included here. The condition is not part of this code, but a patient may have both, and both codes may be reported together.

  • 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-)

More specific codes under F51.1

Related codes in F51

Where this code sits

Parent code
F51

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Source

ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.

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