2026 ICD-10-CM Diagnosis Code G44.011Episodic cluster headache, intractable

ICD-10-CM Codes›G00–G99›G40-G47›G44

ICD-10-CM G44.011
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G44.011 is a billable ICD-10-CM diagnosis code for episodic cluster headache, 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 cluster headache. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Headache; including migraine.

Code Identity

ICD-10-CM Code
G44.011
Billable Status
Yes — Valid for Submission
Code Describes
Episodic cluster headache, intractable
Short Description
Episodic cluster headache, intractable
Same as the full description in the CMS dataset.
Parent Code
G44.01
Episodic cluster headache

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG44Other headache syndromes
This CodeG44.011Episodic cluster headache, intractable

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cluster headache
  • Episodic cluster headache
  • Intractable episodic cluster headache

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
      • cluster
        • episodic
          • 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

Clinical InformationClinical

  • Cluster Headache

    a primary headache disorder that is characterized by severe, strictly unilateral pain which is orbital, supraorbital, temporal or in any combination of these sites, lasting 15-180 min. occurring 1 to 8 times a day. the attacks are associated with one or more of the following, all of which are ipsilateral: conjunctival injection, lacrimation, nasal congestion, rhinorrhea, facial sweating, eyelid edema, and miosis. (international classification of headache disorders, 2nd ed. cephalalgia 2004: suppl 1)

  • Cluster Headache

    a headache disorder that is characterized by periodic severe, unilateral orbital, supraorbital, and/or temporal pain, and is associated with ipsilateral cranial autonomic symptoms.

Patient EducationClinical

Headache

Almost everyone has had a headache. Headache is the most common form of pain. It's a major reason people miss days at work or school or visit the doctor.

Read the full article at MedlinePlus

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

Convert G44.011 to ICD-9-CMHistory

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

ICD-9-CM
339.01 Episodc cluster headache
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 G44.011Overview

Is G44.011 (Episodic cluster headache) a billable code?

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

What MS-DRG does G44.011 group to?

When episodic cluster headache, 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 G44.011?

Under the General Equivalence Mappings, episodic cluster headache, intractable converts to ICD-9-CM 339.01 (episodc cluster headache). 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.