2026 ICD-10-CM Diagnosis Code M26.639Articular disc disorder of temporomandibular joint, unspecified side

ICD-10-CM Codes›M00–M99›M26-M27›M26

ICD-10-CM M26.639
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M26.639 is a billable ICD-10-CM diagnosis code for articular disc disorder of temporomandibular joint, unspecified side. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 157 through 159. Coders also document this condition as abnormal form of articular disk of temporomandibular joint. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Any dental condition including traumatic injury, Disorders of jaw, and Nontraumatic dental conditions.

Code Identity

ICD-10-CM Code
M26.639
Billable Status
Yes — Valid for Submission
Code Describes
Articular disc disorder of temporomandibular joint, unspecified side
Short Description
Articular disc disorder of TMJ joint, unspecified side
Parent Code
M26.63
Articular disc disorder of temporomandibular joint

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM26-M27Dentofacial anomalies [including malocclusion] and other disorders of jaw
CategoryM26Dentofacial anomalies [including malocclusion]
This CodeM26.639Articular disc disorder of temporomandibular joint, unspecified side

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal form of articular disk of temporomandibular joint
  • Abnormal form of temporomandibular joint fossa
  • Articular disc disorder of temporomandibular joint
  • Derangement of temporomandibular joint
  • Injury of meniscus of temporomandibular joint
  • Temporomandibular joint disc displacement
  • Temporomandibular joint disc displacement without reduction with limited opening
  • Temporomandibular joint disc displacement, with reduction
  • Temporomandibular joint disc displacement, without reduction

Clinical ClassificationClinical

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

CCSR DEN001
Any dental condition including traumatic injury
Default principal diagnosis: inpatient No · outpatient No
CCSR MUS029
Disorders of jaw
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR DEN002
Nontraumatic dental conditions
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Temporomandibular Disorders

Temporomandibular disorders (TMDs) are a group of more than 30 conditions that affect your temporomandibular joints (TMJs). You have two TMJs; one on each side of your jaw. They connect your lower jaw to your skull.

The full article covers:

  • What are temporomandibular disorders (TMDs)?
  • What causes temporomandibular disorders (TMDs)?
  • Who is more likely to develop a temporomandibular disorder (TMD)?
  • What are the symptoms of temporomandibular disorders (TMDs)?
  • How are temporomandibular disorders (TMDs) diagnosed?
  • What are the treatments for temporomandibular disorders (TMDs)?

Read the full article at MedlinePlus

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

Convert M26.639 to ICD-9-CMHistory

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

ICD-9-CM
524.63 Articular disc disorder
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement M26.639 replaces the following previously assigned code(s):

  • M26.63 - Articular disc disorder of temporomandibular joint
FY 2018AddedAdded to the ICD-10-CM code setEffective October 1, 2017.
FY 2019–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M26.639Overview

Is M26.639 (Articular disc disorder of temporomandibular joint) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report articular disc disorder of temporomandibular joint, unspecified side on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M26.639 group to?

When articular disc disorder of temporomandibular joint, unspecified side is the principal diagnosis on an inpatient stay, it groups to MS-DRG 157, 158, 159, with relative weights from 0.7085 to 1.7168 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M26.639?

Under the General Equivalence Mappings, articular disc disorder of temporomandibular joint, unspecified side converts to ICD-9-CM 524.63 (articular disc disorder). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.