2026 ICD-10-CM Diagnosis Code M79.7Fibromyalgia

ICD-10-CM Codes›M00–M99›M70-M79›M79

ICD-10-CM M79.7
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M79.7 is a billable ICD-10-CM diagnosis code for fibromyalgia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 555 through 556. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified connective tissue disease.

Code Identity

ICD-10-CM Code
M79.7
Billable Status
Yes — Valid for Submission
Code Describes
Fibromyalgia
Short Description
Fibromyalgia
Same as the full description in the CMS dataset.
Parent Code
M79
Other and unspecified soft tissue disorders, not elsewhere classified

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM70-M79Other soft tissue disorders
CategoryM79Other and unspecified soft tissue disorders, not elsewhere classified
This CodeM79.7Fibromyalgia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Fibromyalgia
  • Fibromyositis
  • Fibrositis
  • Fibrositis and nodular fasciitis
  • Fibrositis of neck
  • Muscular rheumatism
  • Primary fibromyalgia syndrome
  • Primary fibrositis
  • Scapulohumeral fibrositis
  • Secondary fibrositis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Fibromyositis
  • Fibrositis
  • Myofibrositis

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.

    • Fibromyalgia
    • Fibromyositis
    • Fibrositis(periarticular)
    • Myofibrositis

Clinical ClassificationClinical

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

CCSR MUS025
Other specified connective tissue disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Fibromyalgia

    a common nonarticular rheumatic syndrome characterized by myalgia and multiple points of focal muscle tenderness to palpation (trigger points). muscle pain is typically aggravated by inactivity or exposure to cold. this condition is often associated with general symptoms, such as sleep disturbances, fatigue, stiffness, headaches, and occasionally depression. there is significant overlap between fibromyalgia and the chronic fatigue syndrome (fatigue syndrome, chronic). fibromyalgia may arise as a primary or secondary disease process. it is most frequent in females aged 20 to 50 years. (from adams et al., principles of neurology, 6th ed, p1494-95)

  • Fibromyositis

    inflammation and fibrous degeneration of a muscle.

Patient EducationClinical

Fibromyalgia

Fibromyalgia is chronic (long-lasting) condition that causes pain all over the body, fatigue, and other symptoms. There is no cure, but treatments can help with the symptoms.

The full article covers:

  • What causes fibromyalgia?
  • Who is at risk for fibromyalgia?
  • What are the symptoms of fibromyalgia?
  • How is fibromyalgia diagnosed?
  • What are the treatments for fibromyalgia?

Read the full article at MedlinePlus

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

Convert M79.7 to ICD-9-CMHistory

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

ICD-9-CM
729.1 Myalgia and myositis NOS
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 M79.7Overview

Is M79.7 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report fibromyalgia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M79.7 group to?

When fibromyalgia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 555, 556, with relative weights from 0.8306 to 1.3218 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M79.7?

Under the General Equivalence Mappings, fibromyalgia converts to ICD-9-CM 729.1 (myalgia and myositis NOS). 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.