2027 ICD-10-CM Diagnosis Code G47.419Narcolepsy without cataplexy

ICD-10-CM Codes›G00–G99›G40-G47›G47

ICD-10-CM G47.419
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G47.419 is a billable ICD-10-CM diagnosis code for narcolepsy without cataplexy. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 91 through 93. Coders also document this condition as narcolepsy. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sleep wake disorders.

G47.419 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 355 for payment year 2027.

Code Identity

ICD-10-CM Code
G47.419
Billable Status
Yes — Valid for Submission
Code Describes
Narcolepsy without cataplexy
Short Description
Narcolepsy without cataplexy
Same as the full description in the CMS dataset.
Parent Code
G47.41
Narcolepsy

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG47Sleep disorders
This CodeG47.419Narcolepsy without cataplexy

Medicare Risk Adjustment (HCC)Billing

G47.419 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Part D (RxHCC)
RxHCC 355 — Narcolepsy and Cataplexy
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Narcolepsy
  • Narcolepsy type 1
  • Narcolepsy type 2
  • Sleep attack

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G47.419: its own notes plus those printed at G47 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Narcolepsy NOS

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From G47 Sleep disorders applies to 43 codes
From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • 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)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G47.419, its category, or a range that includes it.

Excludes2 2

These codes carry an Excludes2 note naming G47.419: its condition is not part of those codes, and both may be reported when the patient has both.

  • F51 Sleep disorders not due to a substance or known physiological condition
    organic sleep disorders (G47.-) names G47.-, which includes this code
  • F51.1 Hypersomnia not due to a substance or known physiological condition
    narcolepsy (G47.4-) names G47.4-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

  • Narcolepsy

    a condition characterized by recurrent episodes of daytime somnolence and lapses in consciousness (microsomnias) that may be associated with automatic behaviors and amnesia. cataplexy; sleep paralysis, and hypnagogic hallucinations frequently accompany narcolepsy. the pathophysiology of this disorder includes sleep-onset rapid eye movement (rem) sleep, which normally follows stage iii or iv sleep. (from neurology 1998 feb;50(2 suppl 1):s2-s7)

Patient EducationClinical

Sleep Disorders

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.

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 G47.419 to ICD-9-CMHistory

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

ICD-9-CM
347.00 Narcolepsy w/o cataplexy
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G47.419Overview

What is the ICD-10 code for narcolepsy without cataplexy?

The ICD-10-CM code for narcolepsy without cataplexy is G47.419 (sometimes written as G47419). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G47.419 (Narcolepsy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report narcolepsy without cataplexy on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G47.419 group to?

When narcolepsy without cataplexy is the principal diagnosis on an inpatient stay, it groups to MS-DRG 91, 92, 93, with relative weights from 0.7783 to 1.7050 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of G47.419?

Under the General Equivalence Mappings, narcolepsy without cataplexy converts to ICD-9-CM 347.00 (narcolepsy w/o cataplexy). The mapping is a direct match.

Does G47.419 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: G47.419 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 355 (Narcolepsy and Cataplexy).