2024 ICD-10-CM Diagnosis Code M21.9

Unspecified acquired deformity of limb and hand

ICD-10-CM Code:
M21.9
ICD-10 Code for:
Unspecified acquired deformity of limb and hand
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

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

M21.9 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of unspecified acquired deformity of limb and hand. The code is not specific and is NOT valid for the year 2024 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.

Unspecified diagnosis codes like M21.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Specific Coding Applicable to Unspecified acquired deformity of limb and hand

Non-specific codes like M21.9 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for unspecified acquired deformity of limb and hand:

  • Use M21.90 for Unspecified acquired deformity of unspecified limb - BILLABLE CODE

  • M21.92 for Unspecified acquired deformity of upper arm - NON-BILLABLE CODE

  • Use M21.921 for Unspecified acquired deformity of right upper arm - BILLABLE CODE

  • Use M21.922 for Unspecified acquired deformity of left upper arm - BILLABLE CODE

  • Use M21.929 for Unspecified acquired deformity of unspecified upper arm - BILLABLE CODE

  • M21.93 for Unspecified acquired deformity of forearm - NON-BILLABLE CODE

  • Use M21.931 for Unspecified acquired deformity of right forearm - BILLABLE CODE

  • Use M21.932 for Unspecified acquired deformity of left forearm - BILLABLE CODE

  • Use M21.939 for Unspecified acquired deformity of unspecified forearm - BILLABLE CODE

  • M21.94 for Unspecified acquired deformity of hand - NON-BILLABLE CODE

  • Use M21.941 for Unspecified acquired deformity of hand, right hand - BILLABLE CODE

  • Use M21.942 for Unspecified acquired deformity of hand, left hand - BILLABLE CODE

  • Use M21.949 for Unspecified acquired deformity of hand, unspecified hand - BILLABLE CODE

  • M21.95 for Unspecified acquired deformity of thigh - NON-BILLABLE CODE

  • Use M21.951 for Unspecified acquired deformity of right thigh - BILLABLE CODE

  • Use M21.952 for Unspecified acquired deformity of left thigh - BILLABLE CODE

  • Use M21.959 for Unspecified acquired deformity of unspecified thigh - BILLABLE CODE

  • M21.96 for Unspecified acquired deformity of lower leg - NON-BILLABLE CODE

  • Use M21.961 for Unspecified acquired deformity of right lower leg - BILLABLE CODE

  • Use M21.962 for Unspecified acquired deformity of left lower leg - BILLABLE CODE

  • Use M21.969 for Unspecified acquired deformity of unspecified lower leg - BILLABLE CODE

Patient Education


Arm Injuries and Disorders

Of the 206 bones in your body, three of them are in your arm: the humerus, radius, and ulna. Your arms are also made up of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall, or an accident.

Types of arm injuries include :

  • Tendinitis and bursitis
  • Sprains
  • Dislocations
  • Fractures (broken bones)
  • Nerve problems
  • Osteoarthritis

You may also have problems or injure specific parts of your arm, such as your hand, wrist, elbow, or shoulder.


[Learn More in MedlinePlus]

Hand Injuries and Disorders

No matter how old you are or what you do for a living, you are always using your hands. When there is something wrong with them, you may not be able to do your regular activities.

Hand problems include :

  • Carpal tunnel syndrome - compression of a nerve as it goes through the wrist, often making your fingers feel numb
  • Injuries that result in fractures (broken bones), ruptured ligaments and dislocations
  • Osteoarthritis - wear-and-tear arthritis, which can also cause deformity
  • Tendinitis - irritation of the tendons
  • Disorders and injuries of your fingers and thumb

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.