2026 ICD-10-CM Diagnosis Code G43.C1Periodic headache syndromes in child or adult, intractable

ICD-10-CM CodesG00–G99G40-G47G43

ICD-10-CM G43.C1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G43.C1 is a billable ICD-10-CM diagnosis code for periodic headache syndromes in child or adult, intractable. 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 episodic migraine. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Headache; including migraine.

Code Identity

ICD-10-CM Code
G43.C1
Billable Status
Yes — Valid for Submission
Code Describes
Periodic headache syndromes in child or adult, intractable
Short Description
Periodic headache syndromes in child or adult, intractable
Same as the full description in the CMS dataset.
Parent Code
Periodic headache syndromes in child or adult

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG43Migraine
This CodeG43.C1Periodic headache syndromes in child or adult, intractable

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Episodic migraine
  • Intermittent headache

Tabular List NotesGuidance

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

Inclusion Terms

  • Periodic headache syndromes in child or adult, with refractory migraine

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.

    • Headache
      • periodic syndromes in adults and children
        • with refractory migraine
    • Headache
      • periodic syndromes in adults and children
        • intractable

Clinical ClassificationClinical

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

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

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.C1 to ICD-9-CMHistory

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

ICD-9-CM
346.21 Vrnt mgrn w ntrc mgr NEC
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 G43.C1Overview

Is G43.C1 (Periodic headache syndromes in child or adult) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report periodic headache syndromes in child or adult, intractable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does G43.C1 group to?

When periodic headache syndromes in child or adult, intractable 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.C1?

Under the General Equivalence Mappings, periodic headache syndromes in child or adult, intractable converts to ICD-9-CM 346.21 (vrnt mgrn w ntrc mgr NEC). The mapping is approximate, so confirm the match fits the documentation.

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.