2026 ICD-10-CM Diagnosis Code G44.099Other trigeminal autonomic cephalgias (TAC), not intractable

ICD-10-CM Codes›G00–G99›G40-G47›G44

ICD-10-CM G44.099
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G44.099 is a billable ICD-10-CM diagnosis code for other trigeminal autonomic cephalgias (TAC), not 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 autonomic facial cephalgia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Headache; including migraine.

Code Identity

ICD-10-CM Code
G44.099
Billable Status
Yes — Valid for Submission
Code Describes
Other trigeminal autonomic cephalgias (TAC), not intractable
Short Description
Other trigeminal autonomic cephalgias (TAC), not intractable
Same as the full description in the CMS dataset.
Parent Code
G44.09
Other trigeminal autonomic cephalgias (TAC)

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG44Other headache syndromes
This CodeG44.099Other trigeminal autonomic cephalgias (TAC), not intractable

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Autonomic facial cephalgia
  • Trigeminal autonomic cephalalgia

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.

    • Cephalgia, cephalalgia
      • trigeminal autonomic (TAC) NEC
    • Cephalgia, cephalalgia
      • trigeminal autonomic (TAC) NEC
        • not intractable
    • Horton's headache or neuralgia
    • Horton's headache or neuralgia
      • not intractable
    • Neuralgia, neuralgic(acute)
      • Horton's
    • Neuralgia, neuralgic(acute)
      • Horton's
        • not intractable
    • TAC(trigeminal autonomic cephalgia) NEC
    • TAC(trigeminal autonomic cephalgia) NEC
      • not 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

  • Trigeminal Autonomic Cephalalgia

    a headache disorder characterized by episodes of unilateral, short lasting pain and associated 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 G44.099 to ICD-9-CMHistory

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

ICD-9-CM
339.09 Trigem autonmc cephl 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 G44.099Overview

Is G44.099 (Other trigeminal autonomic cephalgias (TAC)) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other trigeminal autonomic cephalgias (TAC), not intractable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does G44.099 group to?

When other trigeminal autonomic cephalgias (TAC), not 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 G44.099?

Under the General Equivalence Mappings, other trigeminal autonomic cephalgias (TAC), not intractable converts to ICD-9-CM 339.09 (trigem autonmc cephl 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.