2027 ICD-10-CM Diagnosis Code M20Acquired deformities of fingers and toes

ICD-10-CM Codes›M00–M99›M20-M25›M20

ICD-10-CM M20
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M20 is a non-billable ICD-10-CM category code for acquired deformities of fingers and toes, so it cannot be submitted on claims. Use a more specific code from this category instead, such as M20.001, M20.002, M20.009, and M20.011.

Code Identity

ICD-10-CM Code
M20
Billable Status
No — Non-Billable Category
Code Describes
Acquired deformities of fingers and toes
Short Description
Acquired deformities of fingers and toes
Same as the full description in the CMS dataset.
Chapter
M20-M25
Other joint disorders

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM20-M25Other joint disorders
CategoryM20Acquired deformities of fingers and toes
This CodeM20Acquired deformities of fingers and toes

Specific Coding for Acquired deformities of fingers and toesOverview

Non-specific codes like M20 require more characters. Use one of these billable codes instead:

  • 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M20: its own notes plus those printed at block M00-M25, block M20-M25, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block M00-M25 applies to 2,249 codes
  • Disorders affecting predominantly peripheral (limb) joints

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • 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.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block M20-M25 Other joint disorders applies to 719 codes
From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • arthropathic psoriasis (L40.5-)
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • compartment syndrome (traumatic) (T79.A-)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Notes

General instructions on how these codes are used.

From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name M20, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming M20: its condition is not part of those codes, and both may be reported when the patient has both.

  • M21 Other acquired deformities of limbs
    acquired deformities of fingers or toes (M20.-)

Patient EducationClinical

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:

Read the full article at MedlinePlus

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

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About M20Overview

What is the ICD-10 code for acquired deformities of fingers and toes?

M20 is the ICD-10-CM category for acquired deformities of fingers and toes, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is M20 (Acquired deformities of fingers and toes) a billable code?

No. This is a category header that groups the codes for acquired deformities of fingers and toes, and headers cannot be submitted on claims. Claims for acquired deformities of fingers and toes need a more specific code from this category, such as M20.001, M20.002, and M20.009.

Can M20 be reported with a code from Z89?

Not as a rule. The Excludes1 note on M20 lists "acquired absence of fingers and toes (Z89.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).