Coding and coverage · ICD-10-CM
Instructional notes
Chapter 6
Excludes2Not included here: the patient may have both; report both when both are present.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
G47.1
Excludes2Not included here: the patient may have both; report both when both are present.
- 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 due to a mental disorder (F51.13)
- hypersomnia not due to a substance or known physiological condition (F51.1-)
- primary hypersomnia (F51.11)
- sleep apnea (G47.3-)
This code
Inclusion terms
- Idiopathic hypersomnia NOS
Chapter 6: Diseases of the nervous system · G40-G47 Episodic and paroxysmal disorders (G40-G47)
Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.
Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.