2026 ICD-10-CM Diagnosis Code M21.062Valgus deformity, not elsewhere classified, left knee

ICD-10-CM Codes›M00–M99›M20-M25›M21

ICD-10-CM M21.062
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M21.062 is a billable ICD-10-CM diagnosis code for valgus deformity, not elsewhere classified, left knee. 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 acquired deformity of left knee. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acquired deformities (excluding foot).

Code Identity

ICD-10-CM Code
M21.062
Billable Status
Yes — Valid for Submission
Code Describes
Valgus deformity, not elsewhere classified, left knee
Short Description
Valgus deformity, not elsewhere classified, left knee
Same as the full description in the CMS dataset.
Parent Code
M21.06
Valgus deformity, not elsewhere classified, knee

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM20-M25Other joint disorders
CategoryM21Other acquired deformities of limbs
This CodeM21.062Valgus deformity, not elsewhere classified, left knee

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired deformity of left knee
  • Acquired deformity of right knee
  • Acquired genu valgum
  • Acquired genu valgum of bilateral knees
  • Acquired valgus deformity of joint of lower limb
  • Acquired valgus deformity of left knee
  • Bilateral acquired deformity of knee regions
  • Knee joint valgus deformity

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

Knee Injuries and Disorders

Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty walking.

Read the full article at MedlinePlus

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

Convert M21.062 to ICD-9-CMHistory

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

ICD-9-CM
736.41 Genu valgum
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 M21.062Overview

Is M21.062 (Valgus deformity, not elsewhere classified, knee) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report valgus deformity, not elsewhere classified, left knee on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M21.062 group to?

When valgus deformity, not elsewhere classified, left knee 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 M21.062?

Under the General Equivalence Mappings, valgus deformity, not elsewhere classified, left knee converts to ICD-9-CM 736.41 (genu valgum). 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.