2026 ICD-10-CM Diagnosis Code M95.4Acquired deformity of chest and rib

ICD-10-CM Codes›M00–M99›M95›M95

ICD-10-CM M95.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M95.4 is a billable ICD-10-CM diagnosis code for acquired deformity of chest and rib. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acquired deformities (excluding foot).

Code Identity

ICD-10-CM Code
M95.4
Billable Status
Yes — Valid for Submission
Code Describes
Acquired deformity of chest and rib
Short Description
Acquired deformity of chest and rib
Same as the full description in the CMS dataset.
Parent Code
M95
Other acquired deformities of musculoskeletal system and connective tissue

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM95Other disorders of the musculoskeletal system and connective tissue
CategoryM95Other acquired deformities of musculoskeletal system and connective tissue
This CodeM95.4Acquired deformity of chest and rib

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal prominence of rib
  • Acquired deformity of chest wall
  • Acquired deformity of left rib
  • Acquired deformity of rib
  • Acquired deformity of right rib
  • Acquired deformity of thoracic structure
  • Acquired pectus carinatum
  • Acquired pectus excavatum
  • Angulation deformity of rib
  • Barrel chest
  • Beading of ribs
  • Bilateral acquired deformity of ribs
  • Bowing of rib
  • Chest deformity due to ankylosing spondylitis
  • Chest movement appearance finding
  • Deformity of chest due to kyphoscoliosis
  • Deformity of chest wall
  • Deformity of rib
  • Deformity of sternum
  • Deformity of thoracic structure
  • Enlargement of thorax
  • Finding of appearance of thorax
  • Finding of arrangement of ribs
  • Finding of size of thorax
  • Flared ribs
  • Flat chest
  • Gap in ribs
  • Harrison's sulcus
  • Hemithorax immobile
  • Misshapen sternum
  • Muscle rigidity
  • Named sign of thorax
  • Notching of ribs
  • Pectus carinatum
  • Pectus deformity of chest
  • Pectus excavatum
  • Rib hump
  • Rib syndrome
  • Rigid chest
  • Scoliotic angulation of ribs
  • Scorbutic rosary

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.

    • Barrel chest
    • Concavity chest wall
    • Deformity
      • chest (acquired) (wall)
    • Deformity
      • rib (acquired)
    • Deformity
      • sternum (acquired)
    • Deformity
      • thorax (acquired) (wall)
    • Depression(acute) (mental)
      • chest wall
    • Depression(acute) (mental)
      • sternum
    • Funnel
      • breast (acquired)
    • Funnel
      • chest (acquired)
    • Pectus
      • carinatum (congenital)
        • acquired
    • Pectus
      • excavatum (congenital)
        • acquired
    • Pigeon
      • breast or chest (acquired)
    • Retraction
      • sternum (congenital)
        • acquired
    • Shoemaker's chest

Clinical ClassificationClinical

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

CCSR MUS023
Acquired deformities (excluding foot)
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Muscle Rigidity

    continuous involuntary sustained muscle contraction which is often a manifestation of basal ganglia diseases. when an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. this feature helps to distinguish rigidity from muscle spasticity. (from adams et al., principles of neurology, 6th ed, p73)

  • Pectus Carinatum

    a developmental anomaly characterized by abnormal anterior protrusion of the sternum and adjacent costal cartilage.

Patient EducationClinical

Chest Injuries and Disorders

The chest is the part of your body between your neck and your abdomen (belly). The medical term for your chest is thorax.

The full article covers:

  • What is the chest?
  • What are chest injuries and disorders?
  • How are chest injuries and disorders diagnosed?

Read the full article at MedlinePlus

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

Convert M95.4 to ICD-9-CMHistory

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

ICD-9-CM
738.3 Acq chest deformity
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 M95.4Overview

Is M95.4 a billable code?

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

What MS-DRG does M95.4 group to?

When acquired deformity of chest and rib is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, with relative weights from 0.7493 to 1.5436 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M95.4?

Under the General Equivalence Mappings, acquired deformity of chest and rib converts to ICD-9-CM 738.3 (acq chest deformity). 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.