2026 ICD-10-CM Diagnosis Code G43.409Hemiplegic migraine, not intractable, without status migrainosus

ICD-10-CM Codes›G00–G99›G40-G47›G43

ICD-10-CM G43.409
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G43.409 is a billable ICD-10-CM diagnosis code for hemiplegic migraine, not intractable, without status migrainosus. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 102 through 103. Coders also document this condition as familial hemiplegic migraine. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Headache; including migraine.

Code Identity

ICD-10-CM Code
G43.409
Billable Status
Yes — Valid for Submission
Code Describes
Hemiplegic migraine, not intractable, without status migrainosus
Short Description
Hemiplegic migraine, not intractable, w/o status migrainosus
Parent Code
G43.40
Hemiplegic migraine, not intractable

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG43Migraine
This CodeG43.409Hemiplegic migraine, not intractable, without status migrainosus

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Familial hemiplegic migraine
  • Familial hemiplegic migraine type 1
  • Familial hemiplegic migraine type 2
  • Familial hemiplegic migraine type 3
  • Hemiplegic migraine
  • Sporadic hemiplegic migraine

Tabular List NotesGuidance

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

Inclusion Terms

  • Hemiplegic migraine 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.

    • Migraine(idiopathic)
      • hemiplegic
    • Migraine(idiopathic)
      • hemiplegic
        • not intractable
    • Migraine(idiopathic)
      • hemiplegic
        • not intractable
          • without status migrainosus
    • Migraine(idiopathic)
      • hemiplegic
        • without refractory migraine
    • Migraine(idiopathic)
      • hemiplegic
        • without refractory migraine
          • without status migrainosus

Clinical ClassificationClinical

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

CCSR NVS010
Headache; including migraine
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Familial Hemiplegic Migraine

    a migraine disorder characterized by individual and family history of aura that includes motor weakness.

  • Familial Hemiplegic Migraine-1|FHM1

    an autosomal dominant subtype of familial hemiplegic migraine caused by mutation(s) in the cacna1a gene, encoding voltage-dependent p/q-type calcium channel subunit alpha-1a.

  • Sporadic Hemiplegic Migraine

    a migraine disorder characterized by an aura that includes motor weakness and the absence of family history.

  • Familial Hemiplegic Migraine-3|FHM3

    an autosomal dominant subtype of familial hemiplegic migraine caused by mutation(s) in the scn1a gene, encoding sodium channel protein type 1 subunit alpha.

Patient EducationClinical

Migraine

Migraines are a recurring type of headache. They cause moderate to severe pain that is throbbing or pulsing. The pain is often on one side of your head. You may also have other symptoms, such as nausea and weakness. You may be sensitive to light and sound.

The full article covers:

  • What are migraines?
  • What causes migraines?
  • Who is at risk for migraines?
  • What are the symptoms of migraines?
  • How are migraines diagnosed?
  • How are migraines treated?

Read the full article at MedlinePlus

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

Convert G43.409 to ICD-9-CMHistory

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

ICD-9-CM
346.30 Hmplg mgr wo ntrc wo st
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G43.409Overview

Is G43.409 (Hemiplegic migraine, not intractable) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report hemiplegic migraine, not intractable, without status migrainosus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does G43.409 group to?

When hemiplegic migraine, not intractable, without status migrainosus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 102, 103, with relative weights from 0.8363 to 1.1209 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of G43.409?

Under the General Equivalence Mappings, hemiplegic migraine, not intractable, without status migrainosus converts to ICD-9-CM 346.30 (hmplg mgr wo ntrc wo st). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.