ICD-10-CM 2027
ICD-10 code for Myofibrositis
From the official ICD-10-CM alphabetic index entry “Myofibrositis”. Page updated September 29, 2026.
About coding Myofibrositis
The ICD-10-CM code for Myofibrositis is M79.7 (Fibromyalgia).
Within M79 (other and unspecified soft tissue disorders, not elsewhere classified), M79.7 is specifically for Fibromyalgia. Related codes cover rheumatism, unspecified (M79.0), myalgia (M79.1), neuralgia and neuritis, unspecified (M79.2), panniculitis, unspecified (M79.3), hypertrophy of (infrapatellar) fat pad (M79.4), residual foreign body in soft tissue (M79.5), pain in limb, hand, foot, fingers and toes (M79.6), other specified soft tissue disorders (M79.8) and 2 more.
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.
More specific Myofibrositis codes (official index)
- scapulohumeral
Common questions about Myofibrositis ICD-10 codes
What is the ICD-10 code for Myofibrositis?
- M79.7 — Fibromyalgia.
Is M79.7 billable?
- Yes. M79.7 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M79.7 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M79.7 as a principal diagnosis.
Is M79.7 a CC or MCC?
- No. M79.7 is neither a CC nor an MCC under MS-DRG v44.0.