M21 - Other acquired deformities of limbs

Version 2023
ICD-10:M21
Short Description:Other acquired deformities of limbs
Long Description:Other acquired deformities of limbs
Status: Not Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Diseases of the musculoskeletal system and connective tissue (M00–M99)
    • Other joint disorders (M20-M25)
      • Other acquired deformities of limbs (M21)

M21 is a non-specific and non-billable ICD-10 code code, consider using a code with a higher level of specificity for a diagnosis of other acquired deformities of limbs. The code is not specific and is NOT valid for the year 2023 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding for Other acquired deformities of limbs

Non-specific codes like M21 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10 codes with a higher level of specificity when coding for other acquired deformities of limbs:

  • NON-BILLABLE CODE - M21.0 for Valgus deformity, not elsewhere classified
  • BILLABLE CODE - Use M21.00 for Valgus deformity, not elsewhere classified, unspecified site
  • NON-BILLABLE CODE - M21.02 for Valgus deformity, not elsewhere classified, elbow
  • NON-BILLABLE CODE - M21.05 for Valgus deformity, not elsewhere classified, hip
  • NON-BILLABLE CODE - M21.06 for Valgus deformity, not elsewhere classified, knee
  • NON-BILLABLE CODE - M21.07 for Valgus deformity, not elsewhere classified, ankle
  • NON-BILLABLE CODE - M21.1 for Varus deformity, not elsewhere classified
  • BILLABLE CODE - Use M21.10 for Varus deformity, not elsewhere classified, unspecified site
  • NON-BILLABLE CODE - M21.12 for Varus deformity, not elsewhere classified, elbow
  • NON-BILLABLE CODE - M21.15 for Varus deformity, not elsewhere classified, hip
  • NON-BILLABLE CODE - M21.16 for Varus deformity, not elsewhere classified, knee
  • NON-BILLABLE CODE - M21.17 for Varus deformity, not elsewhere classified, ankle
  • NON-BILLABLE CODE - M21.2 for Flexion deformity
  • BILLABLE CODE - Use M21.20 for Flexion deformity, unspecified site
  • NON-BILLABLE CODE - M21.21 for Flexion deformity, shoulder
  • NON-BILLABLE CODE - M21.22 for Flexion deformity, elbow
  • NON-BILLABLE CODE - M21.23 for Flexion deformity, wrist
  • NON-BILLABLE CODE - M21.24 for Flexion deformity, finger joints
  • NON-BILLABLE CODE - M21.25 for Flexion deformity, hip
  • NON-BILLABLE CODE - M21.26 for Flexion deformity, knee
  • NON-BILLABLE CODE - M21.27 for Flexion deformity, ankle and toes
  • NON-BILLABLE CODE - M21.3 for Wrist or foot drop (acquired)
  • NON-BILLABLE CODE - M21.33 for Wrist drop (acquired)
  • NON-BILLABLE CODE - M21.37 for Foot drop (acquired)
  • NON-BILLABLE CODE - M21.4 for Flat foot [pes planus] (acquired)
  • BILLABLE CODE - Use M21.40 for Flat foot [pes planus] (acquired), unspecified foot
  • BILLABLE CODE - Use M21.41 for Flat foot [pes planus] (acquired), right foot
  • BILLABLE CODE - Use M21.42 for Flat foot [pes planus] (acquired), left foot
  • NON-BILLABLE CODE - M21.5 for Acquired clawhand, clubhand, clawfoot and clubfoot
  • NON-BILLABLE CODE - M21.51 for Acquired clawhand
  • NON-BILLABLE CODE - M21.52 for Acquired clubhand
  • NON-BILLABLE CODE - M21.53 for Acquired clawfoot
  • NON-BILLABLE CODE - M21.54 for Acquired clubfoot
  • NON-BILLABLE CODE - M21.6 for Other acquired deformities of foot
  • NON-BILLABLE CODE - M21.61 for Bunion
  • NON-BILLABLE CODE - M21.62 for Bunionette
  • NON-BILLABLE CODE - M21.6X for Other acquired deformities of foot
  • NON-BILLABLE CODE - M21.7 for Unequal limb length (acquired)
  • BILLABLE CODE - Use M21.70 for Unequal limb length (acquired), unspecified site
  • NON-BILLABLE CODE - M21.72 for Unequal limb length (acquired), humerus
  • NON-BILLABLE CODE - M21.73 for Unequal limb length (acquired), ulna and radius
  • NON-BILLABLE CODE - M21.75 for Unequal limb length (acquired), femur
  • NON-BILLABLE CODE - M21.76 for Unequal limb length (acquired), tibia and fibula
  • NON-BILLABLE CODE - M21.8 for Other specified acquired deformities of limbs
  • BILLABLE CODE - Use M21.80 for Other specified acquired deformities of unspecified limb
  • NON-BILLABLE CODE - M21.82 for Other specified acquired deformities of upper arm
  • NON-BILLABLE CODE - M21.83 for Other specified acquired deformities of forearm
  • NON-BILLABLE CODE - M21.85 for Other specified acquired deformities of thigh
  • NON-BILLABLE CODE - M21.86 for Other specified acquired deformities of lower leg
  • NON-BILLABLE CODE - M21.9 for Unspecified acquired deformity of limb and hand
  • BILLABLE CODE - Use M21.90 for Unspecified acquired deformity of unspecified limb
  • NON-BILLABLE CODE - M21.92 for Unspecified acquired deformity of upper arm
  • NON-BILLABLE CODE - M21.93 for Unspecified acquired deformity of forearm
  • NON-BILLABLE CODE - M21.94 for Unspecified acquired deformity of hand
  • NON-BILLABLE CODE - M21.95 for Unspecified acquired deformity of thigh
  • NON-BILLABLE CODE - M21.96 for Unspecified acquired deformity of lower leg

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 coding notes and guidance for inclusions, exclusions, descriptions and more. The following references are applicable to this diagnosis code:


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.

Type 2 Excludes

Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

Patient Education


Joint Disorders

What are joints?

Your joints are places where two or more bones come together. Your shoulders, elbows, hips, knees, and knuckles are all joints. Your spine has joints, too.

But joints are more than bones. They include the soft tissues around them, such as cartilage, tendons and ligaments. Cartilage is the hard slippery flexible tissue that covers the ends of your bones at a joint. Tendons are tough, flexible bands that connect your muscles to your bones so you can move your joints. Ligaments connect the bones of the joint to each other to keep them stable when you move.

What are joint disorders?

Joint disorders are diseases or injuries that affect your joints. Injuries can happen because of overuse of a joint. Or you could have a sudden injury, such as an accident or a sports injury.

What diseases can affect the joints?

Many diseases can affect the joints. They often cause joint pain and make your joints stiff, red, or swollen. Most of them are chronic. That means they last a long time. Some may never go away completely. Some of the diseases that affect the joints include:

Treatments are different depending on the disease. But most treatments include medicines and therapies to relieve pain and other symptoms.

What types of joint disorders happen from sudden injuries?

Joint disorders from sudden injuries include:

Treatment depends on the type of injury. You can treat many sports injuries at home. But you should call your health care provider if you:

What types of joint disorders happen from overuse?

Overuse injuries usually damage the soft tissues of the joint. They can happen when you work a joint too hard by doing the same movements over and over. For example, you could get an overuse injury from playing a musical instrument, playing sports, or doing certain jobs, such as carpentry or painting.

Joint overuse injuries include:

The treatments for bursitis, tendinitis, and chronic strain are often the same. They usually include rest, keeping the injured joint higher than your heart, and taking medicine to reduce swelling. Your provider may recommend gentle exercise and other treatment. In some cases, your provider may suggest an injection (a shot) of medicine into the joint. If these do not help, you may need surgery.

How can I keep my joints healthy?

Getting enough physical activity is one of the most important things you can do to prevent or slow joint disorders. Activity strengthens the muscles around your joints and helps them work better.

When you play sports, wear the right equipment to protect your joints, such as knee pads. If you already have joint problems, ask your provider what type of activities are best for you.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases


[Learn More in MedlinePlus]

Code History