ICD-10-CM Code M21.1

Varus deformity, not elsewhere classified

Version 2020 Non-Billable Code

Not Valid for Submission

M21.1 is a "header" nonspecific and non-billable code code, consider using a code with a higher level of specificity for a diagnosis of varus deformity, not elsewhere classified. The code is NOT valid for the year 2020 for the submission of HIPAA-covered transactions.

ICD-10:M21.1
Short Description:Varus deformity, not elsewhere classified
Long Description:Varus deformity, not elsewhere classified

Consider the following ICD-10 codes with a higher level of specificity:

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code M21.1:

Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code M21.1 are found in the index:


Code Classification

  • Diseases of the musculoskeletal system and connective tissue (M00–M99)
    • Other joint disorders (M20-M25)
      • Other acquired deformities of limbs (M21)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Patients


Joint Disorders

A joint is where two or more bones come together, like the knee, hip, elbow, or shoulder. Joints can be damaged by many types of injuries or diseases, including

  • Arthritis - inflammation of a joint. It causes pain, stiffness, and swelling. Over time, the joint can become severely damaged.
  • Bursitis - inflammation of a fluid-filled sac that cushions the joint
  • Dislocations - injuries that force the ends of the bones out of position

Treatment of joint problems depends on the cause. If you have a sports injury, treatment often begins with the RICE (Rest, Ice, Compression, and Elevation) method to relieve pain, reduce swelling, and speed healing. Other possible treatments include pain relievers, keeping the injured area from moving, rehabilitation, and sometimes surgery. For arthritis, injuries, or other diseases, you may need joint replacement surgery to remove the damaged joint and put in a new one.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases


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