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ICD-10-CM 2027 diagnosis code

M23.00Cystic meniscus, unspecified meniscus

Not billable — use a more specific code

M23.00 is a header code, so it can't be reported by itself. Choose one of the 9 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About M23.00

M23.00 is the ICD-10-CM diagnosis code for cystic meniscus, unspecified meniscus. It belongs to category M23 (internal derangement of knee), block M20-M25 (other joint disorders) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is a header code, so it can't be reported by itself; one of its 9 subcodes must be used instead.

Within M23.0, choose M23.00 (unspecified meniscus) only when documentation doesn't support a more specific option: anterior horn of medial meniscus (M23.01), posterior horn of medial meniscus (M23.02), other medial meniscus (M23.03), anterior horn of lateral meniscus (M23.04), posterior horn of lateral meniscus (M23.05) and other lateral meniscus (M23.06).

To report this condition, pick the subcode that matches the documentation: M23.000 (knee), M23.001 (knee), M23.002 (knee), M23.003 (knee), M23.004 (knee), M23.005 (knee), M23.006 (right knee), M23.007 (left knee) and 1 more.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under M23.00

Coding notes

Applicable toConditions and synonyms classified to this code
  • Cystic meniscus, unspecified lateral meniscus
  • Cystic meniscus, unspecified medial meniscus

Notes that apply from higher levels

Instructions written at a parent level also apply to M23.00.

› From M23 Internal derangement of knee
Excludes1
  • ankylosis (M24.66)
  • deformity of knee (M21.-)
  • osteochondritis dissecans (M93.2)
Excludes2
  • 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)

Broader instructions also apply from M20-M25 Other joint disorders and Chapter 13: Diseases of the musculoskeletal system and connective tissue.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about M23.00

Is M23.00 billable?

No. M23.00 is a header code. Report one of its more specific subcodes instead.