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  6. 2026 ICD-10-CM Code M20

2026 ICD-10-CM Diagnosis Code M20

Acquired deformities of fingers and toes

ICD-10-CM Code:
M20
ICD-10 Code for:
Acquired deformities of fingers and toes
Is Billable?
Not Valid for Submission
Code Navigator:

M20 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity from the list below for a diagnosis of acquired deformities of fingers and toes. The code is not specific and is NOT valid for the year 2026 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 Applicable to Acquired deformities of fingers and toes

Non-specific codes like M20 require more digits to indicate the appropriate level of specificity. Consider using any of the following billable codes with a higher level of specificity when coding for acquired deformities of fingers and toes:

  • M20.0 for Deformity of finger(s)

  • M20.00 for Unspecified deformity of finger(s)

  • M20.01 for Mallet finger

  • M20.02 for Boutonniere deformity

  • M20.03 for Swan-neck deformity

  • M20.09 for Other deformity of finger(s)

  • M20.1 for Hallux valgus (acquired)

  • Use M20.10 for Hallux valgus (acquired), unspecified foot

  • Use M20.11 for Hallux valgus (acquired), right foot

  • Use M20.12 for Hallux valgus (acquired), left foot

  • M20.2 for Hallux rigidus

  • Use M20.20 for Hallux rigidus, unspecified foot

  • Use M20.21 for Hallux rigidus, right foot

  • Use M20.22 for Hallux rigidus, left foot

  • M20.3 for Hallux varus (acquired)

  • Use M20.30 for Hallux varus (acquired), unspecified foot

  • Use M20.31 for Hallux varus (acquired), right foot

  • Use M20.32 for Hallux varus (acquired), left foot

  • M20.4 for Other hammer toe(s) (acquired)

  • Use M20.40 for Other hammer toe(s) (acquired), unspecified foot

  • Use M20.41 for Other hammer toe(s) (acquired), right foot

  • Use M20.42 for Other hammer toe(s) (acquired), left foot

  • M20.5 for Other deformities of toe(s) (acquired)

  • M20.5X for Other deformities of toe(s) (acquired)

  • M20.6 for Acquired deformities of toe(s), unspecified

  • Use M20.60 for Acquired deformities of toe(s), unspecified, unspecified foot

  • Use M20.61 for Acquired deformities of toe(s), unspecified, right foot

  • Use M20.62 for Acquired deformities of toe(s), unspecified, left foot

Code Classification

  • Diseases of the musculoskeletal system and connective tissue
    M00–M99
    • Other joint disorders
      M20-M25
      • Acquired deformities of fingers and toes
        M20

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


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.
  • acquired absence of fingers and toes Z89
  • congenital absence of fingers and toes Q71.3 Q72.3
  • congenital deformities and malformations of fingers and toes Q66 Q68 Q70 Q74

Patient Education


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:

  • Injuries that result in fractures (broken bones), ruptured ligaments and dislocations
  • Osteoarthritis - wear-and-tear arthritis. It can also cause deformity.
  • Tendinitis - irritation of the tendons
  • Dupuytren's contracture - a hereditary thickening of the tough tissue that lies just below the skin of your palm. It causes the fingers to stiffen and bend.
  • Trigger finger - an irritation of the sheath that surrounds the flexor tendons. It can cause the tendon to catch and release like a trigger.

[Learn More in MedlinePlus]

Code History

  • FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
  • FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
  • 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.