2026 ICD-10-CM Diagnosis Code M62.5A9Muscle wasting and atrophy, not elsewhere classified, back, unspecified level

ICD-10-CM Codes›M00–M99›M60-M63›M62

ICD-10-CM M62.5A9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M62.5A9 is a billable ICD-10-CM diagnosis code for muscle wasting and atrophy, not elsewhere classified, back, unspecified level. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Muscle disorders.

Code Identity

ICD-10-CM Code
M62.5A9
Billable Status
Yes — Valid for Submission
Code Describes
Muscle wasting and atrophy, not elsewhere classified, back, unspecified level
Short Description
Muscle wasting and atrophy, NEC, back, unspecified level
Parent Code
M62.5A
Muscle wasting and atrophy, not elsewhere classified, back

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM60-M63Disorders of muscles
CategoryM62Other disorders of muscle
This CodeM62.5A9Muscle wasting and atrophy, not elsewhere classified, back, unspecified level

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.

    • Atrophy, atrophic(of)
      • muscle, muscular (diffuse) (general) (idiopathic) (primary)
        • back

Clinical ClassificationClinical

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

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

Code History & ChangesHistory

Replacement M62.5A9 replaces the following previously assigned code(s):

  • M62.58 - Muscle wasting and atrophy, NEC, oth site
FY 2023AddedAdded to the ICD-10-CM code setEffective October 1, 2022.
FY 2024–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M62.5A9Overview

Is M62.5A9 (Muscle wasting and atrophy, not elsewhere classified, back) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report muscle wasting and atrophy, not elsewhere classified, back, unspecified level on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M62.5A9 group to?

When muscle wasting and atrophy, not elsewhere classified, back, unspecified level 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.

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.