2026 ICD-10-CM Diagnosis Code M60.005Infective myositis, unspecified leg

ICD-10-CM Codes›M00–M99›M60-M63›M60

ICD-10-CM M60.005
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M60.005 is a billable ICD-10-CM diagnosis code for infective myositis, unspecified leg. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 557 through 558. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. Coders also document this condition as abscess of lower leg. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Muscle disorders.

Code Identity

ICD-10-CM Code
M60.005
Billable Status
Yes — Valid for Submission
Code Describes
Infective myositis, unspecified leg
Short Description
Infective myositis, unspecified leg
Same as the full description in the CMS dataset.
Parent Code
M60.00
Infective myositis, unspecified site

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM60-M63Disorders of muscles
CategoryM60Myositis
This CodeM60.005Infective myositis, unspecified leg

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M60.005.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abscess of lower leg
  • Infective myositis of lower leg
  • Inflammation of muscle of lower leg
  • Muscle abscess of lower leg

Tabular List NotesGuidance

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

Inclusion Terms

  • Infective myositis, lower limb NOS

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.

    • Myositis
      • infective
        • leg
    • Myositis
      • infective
        • lower limb

Clinical ClassificationClinical

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

CCSR MUS026
Muscle disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Myositis

Myositis means inflammation of the muscles that you use to move your body. An injury, infection, or autoimmune disease can cause it. Two specific kinds are polymyositis and dermatomyositis. Polymyositis causes muscle weakness, usually in the muscles closest to the trunk of your body.

Read the full article at MedlinePlus

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

Convert M60.005 to ICD-9-CMHistory

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

ICD-9-CM
728.0 Infective myositis
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 M60.005Overview

Is M60.005 (Infective myositis, unspecified site) a billable code?

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

What MS-DRG does M60.005 group to?

When infective myositis, unspecified leg is the principal diagnosis on an inpatient stay, it groups to MS-DRG 557, 558, with relative weights from 0.8932 to 1.4869 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M60.005?

Under the General Equivalence Mappings, infective myositis, unspecified leg converts to ICD-9-CM 728.0 (infective myositis). 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.