2026 ICD-10-CM Diagnosis Code M75.42Impingement syndrome of left shoulder

ICD-10-CM Codes›M00–M99›M70-M79›M75

ICD-10-CM M75.42
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M75.42 is a billable ICD-10-CM diagnosis code for impingement syndrome of left shoulder. 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 Other specified connective tissue disease.

This medical diagnosis code is frequently used in Orthopedics medical specialties to designate conditions such selected shoulder conditions.

Code Identity

ICD-10-CM Code
M75.42
Billable Status
Yes — Valid for Submission
Code Describes
Impingement syndrome of left shoulder
Short Description
Impingement syndrome of left shoulder
Same as the full description in the CMS dataset.
Parent Code
M75.4
Impingement syndrome of shoulder

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM70-M79Other soft tissue disorders
CategoryM75Shoulder lesions
This CodeM75.42Impingement syndrome of left shoulder

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral arthritis of glenohumeral joints
  • Bilateral impingement syndrome of shoulders
  • Impingement syndrome of left shoulder region
  • Impingement syndrome of right shoulder region
  • Internal impingement of bilateral shoulders
  • Internal impingement of left shoulder
  • Internal impingement of right shoulder
  • Subcoracoid impingement of bilateral shoulder regions
  • Subcoracoid impingement of left shoulder region
  • Subcoracoid impingement of right shoulder region
  • Subcoracoid impingement of shoulder region

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

Rotator Cuff Injuries

Your rotator cuff is part of your shoulder joint. It's a group of muscles and tendons that holds the top part of your upper arm bone firmly in your shoulder socket. The rotator cuff keeps your shoulder stable when you move your arm in any direction.

The full article covers:

  • What is a rotator cuff?
  • What are rotator cuff injuries?
  • Who is more likely to develop a rotator cuff injury?
  • What are the symptoms of rotator cuff injuries?
  • How are rotator cuff injuries diagnosed?
  • What are the treatments for rotator cuff injuries?
  • When should I see a health care provider for shoulder pain?

Read the full article at MedlinePlus

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

Convert M75.42 to ICD-9-CMHistory

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

ICD-9-CM
726.2 Shoulder region dis NEC
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 M75.42Overview

Is M75.42 (Impingement syndrome of shoulder) a billable code?

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

What MS-DRG does M75.42 group to?

When impingement syndrome of left shoulder 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 M75.42?

Under the General Equivalence Mappings, impingement syndrome of left shoulder converts to ICD-9-CM 726.2 (shoulder region dis NEC). 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.