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ICD-10-CM 2027 diagnosis code

M79.11Myalgia of mastication muscle

✓ Billable / specific

M79.11 is a valid, billable ICD-10-CM code for myalgia of mastication muscle. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code last changed in FY2019 (effective October 1, 2018). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About M79.11

M79.11 is the ICD-10-CM diagnosis code for myalgia of mastication muscle. It belongs to category M79 (other and unspecified soft tissue disorders, not elsewhere classified), block M70-M79 (other soft tissue disorders) 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 M79.1 (myalgia), M79.11 is specifically for myalgia of mastication muscle. Related codes cover unspecified site (M79.10), of auxiliary muscles, head and neck (M79.12) and other site (M79.18).

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 555 (Signs and Symptoms of Musculoskeletal System and Connective Tissue with MCC, relative weight 1.2913) and DRG 556 (Signs and Symptoms of Musculoskeletal System and Connective Tissue without MCC, relative weight 0.8211), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), 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 FY2019, effective October 1, 2018.

Notes that apply from higher levels

Instructions written at a parent level also apply to M79.11.

› From M79.1 Myalgia
Excludes1
› From M79 Other and unspecified soft tissue disorders, not elsewhere classified
Excludes1
  • psychogenic rheumatism (F45.8)
  • soft tissue pain, psychogenic (F45.41)

Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.

Alphabetic index entries

1 entries

Terms in the official ICD-10-CM index that lead to M79.11.

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.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2019 (effective 10/1/2018): Added
  • No changes since FY2019.

Common questions about M79.11

Is M79.11 billable?

Yes. M79.11 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can M79.11 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict M79.11 as a principal diagnosis.

Is M79.11 a CC or MCC?

No. M79.11 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does M79.11 group to?

M79.11 is used in the MS-DRG v44.0 logic for MS-DRG 555 (Signs and Symptoms of Musculoskeletal System and Connective Tissue with MCC) and MS-DRG 556 (Signs and Symptoms of Musculoskeletal System and Connective Tissue without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.