2026 ICD-10-CM Diagnosis Code M79.9Soft tissue disorder, unspecified

ICD-10-CM Codes›M00–M99›M70-M79›M79

ICD-10-CM M79.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M79.9 is a billable ICD-10-CM diagnosis code for soft tissue disorder, unspecified. 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
M79.9
Billable Status
Yes — Valid for Submission
Code Describes
Soft tissue disorder, unspecified
Short Description
Soft tissue disorder, unspecified
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 CodeM79.9Soft tissue disorder, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute disease of musculoskeletal system
  • Calcinosis following localized fat necrosis
  • Chest wall lesion excised
  • Chronic disease of musculoskeletal system
  • Deformity of tissue
  • Disorder of musculoskeletal system
  • Disorder of soft tissue
  • Disorder of soft tissue due to diabetes mellitus
  • Disorder of soft tissue of abdominal cavity
  • Disorder of soft tissue of body cavity
  • Disorder of soft tissue of body wall region
  • Disorder of soft tissue of head
  • Disorder of soft tissue of limb
  • Disorder of soft tissue of lower limb
  • Disorder of soft tissue of neck
  • Disorder of soft tissue of pelvis
  • Disorder of soft tissue of thoracic cavity
  • Disorder of soft tissue of trunk
  • Disorder of soft tissue of upper limb
  • Lesion of soft tissue
  • Orthopedic disorders during pregnancy, childbirth and the puerperium
  • Pelvic soft tissue abnormality in pregnancy, childbirth and the puerperium
  • Soft tissue lesion of elbow region
  • Soft tissue lesion of foot region
  • Soft tissue lesion of knee region
  • Soft tissue lesion of lower leg and ankle
  • Soft tissue lesion of pelvic region
  • Soft tissue lesion of wrist and hand

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.

    • Disorder(of)
      • soft tissue
    • Disorder(of)
      • soft tissue
        • ankle
    • Disorder(of)
      • soft tissue
        • foot
    • Disorder(of)
      • soft tissue
        • forearm
    • Disorder(of)
      • soft tissue
        • hand
    • Disorder(of)
      • soft tissue
        • lower leg
    • Disorder(of)
      • soft tissue
        • multiple sites
    • Disorder(of)
      • soft tissue
        • pelvic region
    • Disorder(of)
      • soft tissue
        • shoulder region
    • Disorder(of)
      • soft tissue
        • thigh
    • Disorder(of)
      • soft tissue
        • upper arm

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

Patient EducationClinical

Connective Tissue Disorders

Your connective tissue supports many different parts of your body, such as your skin, eyes, and heart. It is like a "cellular glue" that gives your body parts their shape and helps keep them strong. It also helps some of your tissues do their work. It is made of many kinds of proteins. Cartilage and fat are types of connective tissue.

Read the full article at MedlinePlus

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

Convert M79.9 to ICD-9-CMHistory

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

ICD-9-CM
729.90 Soft tissue disord 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 M79.9Overview

Is M79.9 a billable code?

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

What MS-DRG does M79.9 group to?

When soft tissue disorder, unspecified 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 M79.9?

Under the General Equivalence Mappings, soft tissue disorder, unspecified converts to ICD-9-CM 729.90 (soft tissue disord NOS). 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.