ICD-10-CM 2027 diagnosis code
M26.641Arthritis of right temporomandibular joint
M26.641 is a valid, billable ICD-10-CM code for arthritis of right temporomandibular joint. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Code last changed in FY2021 (effective October 1, 2020). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About M26.641
M26.641 is the ICD-10-CM diagnosis code for arthritis of right temporomandibular joint. It belongs to category M26 (dentofacial anomalies [including malocclusion]), block M26-M27 (dentofacial anomalies [including malocclusion] and other disorders of jaw) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within M26.64 (arthritis of temporomandibular joint), M26.641 is specifically for arthritis of right temporomandibular joint. Related codes cover left temporomandibular joint (M26.642), bilateral temporomandibular joint (M26.643) and unspecified temporomandibular joint (M26.649).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 157 (Dental and Oral Diseases with MCC, relative weight 1.809), DRG 158 (Dental and Oral Diseases with CC, relative weight 0.9366) and DRG 159 (Dental and Oral Diseases without CC/MCC, relative weight 0.6893), in Pre-MDC and MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It was added in FY2021, effective October 1, 2020.
Notes that apply from higher levels
Instructions written at a parent level also apply to M26.641.
Broader instructions also apply from M26-M27 Dentofacial anomalies [including malocclusion] and other disorders of jaw and Chapter 13: Diseases of the musculoskeletal system and connective tissue.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC PRE · Pre-MDC
MDC 03 · Diseases and Disorders of the Ear, Nose, Mouth and Throat
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2021 (effective 10/1/2020): Added
- No changes since FY2021.
Common questions about M26.641
Is M26.641 billable?
- Yes. M26.641 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M26.641 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M26.641 as a principal diagnosis.
Is M26.641 a CC or MCC?
- No. M26.641 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does M26.641 group to?
- M26.641 is used in the MS-DRG v44.0 logic for MS-DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC), MS-DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC), MS-DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC), MS-DRG 157 (Dental and Oral Diseases with MCC), MS-DRG 158 (Dental and Oral Diseases with CC) and MS-DRG 159 (Dental and Oral Diseases without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.