2026 ICD-10-CM Diagnosis Code M21.212Flexion deformity, left shoulder

ICD-10-CM Codes›M00–M99›M20-M25›M21

ICD-10-CM M21.212
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M21.212 is a billable ICD-10-CM diagnosis code for flexion deformity, left shoulder. 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. Coders also document this condition as bilateral flexion deformity of joint of shoulder regions. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acquired deformities (excluding foot).

Code Identity

ICD-10-CM Code
M21.212
Billable Status
Yes — Valid for Submission
Code Describes
Flexion deformity, left shoulder
Short Description
Flexion deformity, left shoulder
Same as the full description in the CMS dataset.
Parent Code
M21.21
Flexion deformity, shoulder

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM20-M25Other joint disorders
CategoryM21Other acquired deformities of limbs
This CodeM21.212Flexion deformity, left shoulder

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral flexion deformity of joint of shoulder regions
  • Flexion deformity of joint of left shoulder region
  • Flexion deformity of joint of right shoulder region

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

Patient EducationClinical

Shoulder Injuries and Disorders

Your shoulder joint is composed of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone). Your shoulders are the most movable joints in your body. They can also be unstable because the ball of the upper arm is larger than the shoulder socket that holds it.

Read the full article at MedlinePlus

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

Convert M21.212 to ICD-9-CMHistory

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

ICD-9-CM
736.89 Oth acq limb 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 M21.212Overview

Is M21.212 (Flexion deformity, shoulder) a billable code?

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

What MS-DRG does M21.212 group to?

When flexion deformity, left shoulder 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 M21.212?

Under the General Equivalence Mappings, flexion deformity, left shoulder converts to ICD-9-CM 736.89 (oth acq limb 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.