2026 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 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

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
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

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • 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 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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M20Overview

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.