2026 ICD-10-CM Diagnosis Code M21.249Flexion deformity, unspecified finger joints

ICD-10-CM Codes›M00–M99›M20-M25›M21

ICD-10-CM M21.249
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M21.249 is a billable ICD-10-CM diagnosis code for flexion deformity, unspecified finger joints. 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
M21.249
Billable Status
Yes — Valid for Submission
Code Describes
Flexion deformity, unspecified finger joints
Short Description
Flexion deformity, unspecified finger joints
Same as the full description in the CMS dataset.
Parent Code
M21.24
Flexion deformity, finger joints

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM20-M25Other joint disorders
CategoryM21Other acquired deformities of limbs
This CodeM21.249Flexion deformity, unspecified finger joints

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired fixed flexion deformity of finger
  • Acquired fixed flexion deformity of joint of upper limb
  • Camptodactyly
  • Camptodactyly of finger
  • Camptodactyly, arthropathy, coxa-vara, pericarditis syndrome
  • Camptodactyly-little finger
  • Cold flexed fingers
  • Fixed flexion deformity finger
  • Fixed flexion deformity of the thumb
  • Flexion deformity of finger
  • Flexion deformity of finger, fully flexed position
  • Flexion deformity of finger, semi-flexed position
  • Sporadic camptodactyly
  • Superficial fibromatosis

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

  • Superficial Fibromatosis

    a poorly circumscribed, intermediate fibrocytic neoplasm arising from the superficial soft tissues. it is characterized by the presence of spindle-shaped fibroblasts, and an infiltrative growth pattern.

Patient EducationClinical

Finger Injuries and Disorders

You use your fingers and thumbs to do everything from grasping objects to playing musical instruments to typing. When there is something wrong with them, it can make life difficult. Common problems include:

Read the full article at MedlinePlus

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

Convert M21.249 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 M21.249Overview

Is M21.249 (Flexion deformity, finger joints) a billable code?

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

What MS-DRG does M21.249 group to?

When flexion deformity, unspecified finger joints 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 M21.249?

Under the General Equivalence Mappings, flexion deformity, unspecified finger joints 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.