2026 ICD-10-CM Diagnosis Code M23Internal derangement of knee

ICD-10-CM Codes›M00–M99›M20-M25›M23

ICD-10-CM M23
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M23 is a non-billable ICD-10-CM category code for internal derangement of knee, so it cannot be submitted on claims. Use a more specific code from this category instead, such as M23.000, M23.001, M23.002, and M23.003.

Code Identity

ICD-10-CM Code
M23
Billable Status
No — Non-Billable Category
Code Describes
Internal derangement of knee
Short Description
Internal derangement of knee
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
CategoryM23Internal derangement of knee
This CodeM23Internal derangement of knee

Specific Coding for Internal derangement of kneeOverview

Non-specific codes like M23 require more characters. Use one of these billable codes instead:

  • M23.0 for Cystic meniscus

  • M23.00 for Cystic meniscus, unspecified meniscus

  • M23.01 for Cystic meniscus, anterior horn of medial meniscus

  • M23.02 for Cystic meniscus, posterior horn of medial meniscus

  • M23.03 for Cystic meniscus, other medial meniscus

  • M23.04 for Cystic meniscus, anterior horn of lateral meniscus

  • M23.05 for Cystic meniscus, posterior horn of lateral meniscus

  • M23.06 for Cystic meniscus, other lateral meniscus

  • M23.2 for Derangement of meniscus due to old tear or injury

  • M23.20 for Derangement of unspecified meniscus due to old tear or injury

  • M23.21 for Derangement of anterior horn of medial meniscus due to old tear or injury

  • M23.22 for Derangement of posterior horn of medial meniscus due to old tear or injury

  • M23.23 for Derangement of other medial meniscus due to old tear or injury

  • M23.24 for Derangement of anterior horn of lateral meniscus due to old tear or injury

  • M23.25 for Derangement of posterior horn of lateral meniscus due to old tear or injury

  • M23.26 for Derangement of other lateral meniscus due to old tear or injury

  • M23.3 for Other meniscus derangements

  • M23.30 for Other meniscus derangements, unspecified meniscus

  • M23.31 for Other meniscus derangements, anterior horn of medial meniscus

  • M23.32 for Other meniscus derangements, posterior horn of medial meniscus

  • M23.33 for Other meniscus derangements, other medial meniscus

  • M23.34 for Other meniscus derangements, anterior horn of lateral meniscus

  • M23.35 for Other meniscus derangements, posterior horn of lateral meniscus

  • M23.36 for Other meniscus derangements, other lateral meniscus

  • M23.4 for Loose body in knee

  • Use M23.40 for Loose body in knee, unspecified knee

  • Use M23.41 for Loose body in knee, right knee

  • Use M23.42 for Loose body in knee, left knee

  • M23.5 for Chronic instability of knee

  • Use M23.50 for Chronic instability of knee, unspecified knee

  • Use M23.51 for Chronic instability of knee, right knee

  • Use M23.52 for Chronic instability of knee, left knee

  • M23.6 for Other spontaneous disruption of ligament(s) of knee

  • M23.60 for Other spontaneous disruption of unspecified ligament of knee

  • M23.61 for Other spontaneous disruption of anterior cruciate ligament of knee

  • M23.62 for Other spontaneous disruption of posterior cruciate ligament of knee

  • M23.63 for Other spontaneous disruption of medial collateral ligament of knee

  • M23.64 for Other spontaneous disruption of lateral collateral ligament of knee

  • M23.67 for Other spontaneous disruption of capsular ligament of knee

  • M23.8 for Other internal derangements of knee

  • M23.8X for Other internal derangements of knee

  • M23.9 for Unspecified internal derangement of knee

  • Use M23.90 for Unspecified internal derangement of unspecified knee

  • Use M23.91 for Unspecified internal derangement of right knee

  • Use M23.92 for Unspecified internal derangement of left knee

Tabular List NotesGuidance

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

Type 1 Excludes

  • ankylosis M24.66
  • deformity of knee M21
  • osteochondritis dissecans M93.2

Type 2 Excludes

  • current injury - see injury of knee and lower leg S80 S89
  • recurrent dislocation or subluxation of joints M24.4
  • recurrent dislocation or subluxation of patella M22.0 M22.1

Patient EducationClinical

Knee Injuries and Disorders

Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty walking.

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 M23Overview

Is M23 (Internal derangement of knee) a billable code?

No. This is a category header that groups the codes for internal derangement of knee, and headers cannot be submitted on claims. Claims for internal derangement of knee need a more specific code from this category, such as M23.000, M23.001, and M23.002.