What is ICD-10 code G47.411?

G47.411 is the ICD-10-CM diagnosis code for Narcolepsy with cataplexy. A sleep disorder where a person experiences sudden, uncontrollable episodes of muscle weakness or paralysis (cataplexy) triggered by strong emotions, along with excessive daytime sleepiness. G47.411 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G47.411 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. G47.411 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. G47.411 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for G47.411?

G47.411 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards G47.411 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting G47.411?

Cataplexy is a key distinguishing feature - document whether muscle weakness episodes are present Narcolepsy type 1 includes cataplexy; ensure documentation supports this diagnosis before coding

G47.411 ICD-10 Code: Narcolepsy with cataplexy

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupG47.411Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Episodic and paroxysmal disorders (G40-G47)

G47.411

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Narcolepsy with cataplexy

A sleep disorder where a person experiences sudden, uncontrollable episodes of muscle weakness or paralysis (cataplexy) triggered by strong emotions, along with excessive daytime sleepiness.

Buddy Insight

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 355

Narcolepsy

RAF 0.0

Code Trumping

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Code Book Path

Official

G47.4Narcolepsy and cataplexy

G47.41Narcolepsy

G47.411Narcolepsy with cataplexy

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for G47.411 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for G47.411 in this effective period.

Related Child Codes

Official

G47.419Narcolepsy without cataplexy

Includes

Official

ICD-10-CM does not list Includes notes for G47.411 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for G47.411 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for G47.411 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for G47.411 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for G47.411 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Diagnosis of narcolepsy with documented excessive daytime sleepiness

Cataplexy episodes documented: sudden bilateral loss of muscle tone triggered by strong emotions

Sleep study results: Multiple Sleep Latency Test (MSLT) showing mean sleep latency <=8 minutes with >=2 sleep-onset REM periods

OR cerebrospinal fluid hypocretin-1 levels <=110 pg/mL (definitive for Type 1)

MEAT Support

HCC Buddy guidance

Diagnosis of narcolepsy with documented excessive daytime sleepiness

Cataplexy episodes documented: sudden bilateral loss of muscle tone triggered by strong emotions

Sleep study results: Multiple Sleep Latency Test (MSLT) showing mean sleep latency <=8 minutes with >=2 sleep-onset REM periods

OR cerebrospinal fluid hypocretin-1 levels <=110 pg/mL (definitive for Type 1)

Audit Caution

HCC Buddy guidance

Not documenting cataplexy episodes specifically — 'with cataplexy' requires documented sudden muscle tone loss triggered by emotions

Coding primary narcolepsy when an underlying causative condition exists (or vice versa)

Using secondary narcolepsy codes (G47.42x) when no underlying cause is identified

Not documenting sleep study results (MSLT) that confirm the narcolepsy diagnosis

Common Mistakes

HCC Buddy guidance

G47.419 (Narcolepsy without cataplexy) — Type 2 narcolepsy; lacks the cataplexy component

G47.10 (Hypersomnia, unspecified) — nonspecific excessive sleepiness without narcolepsy diagnosis

G47.421 (Narcolepsy in conditions classified elsewhere, with cataplexy) — use when narcolepsy is secondary to another condition

F51.11 (Hypersomnia due to a mental disorder) — psychiatric cause of excessive sleepiness

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is G47.411 an HCC code?

No. G47.411 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 355, Narcolepsy

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

MEAT Criteria for G47.411

For G47.411to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed G47.411 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

G47.411 is the ICD-10-CM diagnosis code for narcolepsy with cataplexy. A sleep disorder where a person experiences sudden, uncontrollable episodes of muscle weakness or paralysis (cataplexy) triggered by strong emotions, along with excessive daytime sleepiness. G47.411 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering episodic and paroxysmal disorders (g40-g47).

G47.411 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Maps to RxHCC 355 (Narcolepsy and Cataplexy) with a RAF weight of 0.000 in the prescription drug model. No mapping to CMS-HCC V28 or V24 payment models, so this code does not directly affect Medicare Advantage capitation payments. The RxHCC mapping reflects pharmacy costs for wake-promoting agents (modafinil, armodafinil, solriamfetol, pitolisant) and sodium oxybate for cataplexy. No hierarchies apply within payment models.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G47.411 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Cataplexy is a key distinguishing feature - document whether muscle weakness episodes are present
•Narcolepsy type 1 includes cataplexy; ensure documentation supports this diagnosis before coding

Clinical Significance

Narcolepsy with cataplexy (Type 1 narcolepsy) is a chronic neurological disorder caused by loss of hypocretin/orexin-producing neurons, resulting in excessive daytime sleepiness and sudden loss of muscle tone triggered by emotions. This is the most severe form of narcolepsy and significantly impacts patient safety (driving, operating machinery) and quality of life. It maps to RxHCC 355, reflecting the substantial pharmacy costs of wake-promoting agents and cataplexy-specific medications.

Documentation Requirements

✓Diagnosis of narcolepsy with documented excessive daytime sleepiness
✓Cataplexy episodes documented: sudden bilateral loss of muscle tone triggered by strong emotions
✓Sleep study results: Multiple Sleep Latency Test (MSLT) showing mean sleep latency <=8 minutes with >=2 sleep-onset REM periods
✓OR cerebrospinal fluid hypocretin-1 levels <=110 pg/mL (definitive for Type 1)
✓Impact on daily functioning and safety assessment documented
✓Current medication regimen (stimulants, sodium oxybate, pitolisant, solriamfetol)
✓Exclusion of other causes of excessive daytime sleepiness

Commonly Confused Codes

•G47.419 (Narcolepsy without cataplexy): Type 2 narcolepsy; lacks the cataplexy component
•G47.10 (Hypersomnia, unspecified): nonspecific excessive sleepiness without narcolepsy diagnosis
•G47.421 (Narcolepsy in conditions classified elsewhere, with cataplexy): use when narcolepsy is secondary to another condition
•F51.11 (Hypersomnia due to a mental disorder): psychiatric cause of excessive sleepiness
•G47.31-G47.39 (Sleep apnea): can cause excessive daytime sleepiness but is a respiratory disorder

Child Codes

G47.411Narcolepsy with cataplexy

G47.419Narcolepsy without cataplexy

Code Hierarchy

└G47Sleep disorders └G47.4Narcolepsy and cataplexy └G47.41Narcolepsy └G47.411Narcolepsy with cataplexy

└G47.411Narcolepsy with cataplexy

G47.411 ICD-10-CM Code: Narcolepsy with cataplexy

HCC Buddy Code Card

G47.411

Is G47.411 an HCC code?

HCC Category Mapping

MEAT Criteria for G47.411

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Commonly Confused Codes

Child Codes

Code Hierarchy

Open G47.411 in the Interactive Encoder