2026 ICD-10-CM Diagnosis Code G47.10Hypersomnia, unspecified

ICD-10-CM Codes›G00–G99›G40-G47›G47

ICD-10-CM G47.10
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G47.10 is a billable ICD-10-CM diagnosis code for hypersomnia, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as always sleepy. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sleep wake disorders.

Code Identity

ICD-10-CM Code
G47.10
Billable Status
Yes — Valid for Submission
Code Describes
Hypersomnia, unspecified
Short Description
Hypersomnia, unspecified
Same as the full description in the CMS dataset.
Parent Code
G47.1
Hypersomnia

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG47Sleep disorders
This CodeG47.10Hypersomnia, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Always sleepy
  • Disorder of excessive somnolence
  • Excessive somnolence
  • Hypersomnia
  • Hypersomnia with sleep apnea
  • Oversleeps

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Hypersomnia NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Hypersomnia(organic)

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS016
Sleep wake disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Grade 1 Hypersomnia, CTCAE|Grade 1 Hypersomnia

    mild increased need for sleep

  • Grade 2 Hypersomnia, CTCAE|Grade 2 Hypersomnia

    moderate increased need for sleep

  • Grade 3 Hypersomnia, CTCAE|Grade 3 Hypersomnia

    severe increased need for sleep

  • Hypersomnia

    a sleep disorder characterized by excessive sleepiness.

  • Hypersomnia, CTCAE|Hypersomnia|Hypersomnia

    a disorder characterized by characterized by excessive sleepiness during the daytime.

  • Idiopathic Hypersomnia|Primary Hypersomnia|Primary Hypersomnia

    a disorder of central nervous system etiology characterized by excessive sleepiness during the daytime.

  • IDS-C - Hypersomnia|IDSC1-Hypersomnia|IDSC1-Hypersomnia|IDSC104

    inventory of depressive symptomatology clinician-rated version (ids-c) please circle one response to each item that best describes the patient for the last seven days: hypersomnia.

  • QIDS-C - Hypersomnia|QIDSC1-Hypersomnia|QIDSC1-Hypersomnia|QIDSC104

    quick inventory of depressive symptomatology clinician-rated version (qids-c) please circle one response to each item that best describes the patient for the last seven days: hypersomnia.

  • Hypersomnia, CTCAE|Hypersomnia|Hypersomnia

    a disorder characterized by excessive sleepiness during the daytime.

Patient EducationClinical

Sleep Disorders

Sleep is a complex biological process. While you are sleeping, you are unconscious, but your brain and body functions are still active. They are doing a number of important jobs that help you stay healthy and function at your best. So when you don't get enough quality sleep, it does more than just make you feel tired.

The full article covers:

  • What is sleep?
  • What are sleep disorders?
  • What causes sleep disorders?
  • What are the symptoms of sleep disorders?
  • How are sleep disorders diagnosed?
  • What are the treatments for sleep disorders?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G47.10 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
327.10 Organic hypersomnia NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
780.54 Hypersomnia NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G47.10Overview

Is G47.10 (Hypersomnia) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report hypersomnia, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of G47.10?

Under the General Equivalence Mappings, hypersomnia, unspecified converts to ICD-9-CM 327.10 (organic hypersomnia NOS) and 780.54 (hypersomnia NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.