ICD-10-CM › M00-M99 › M20-M25 › M23.5 Chronic instability of knee › M23.50

M23.50

Chronic instability of knee, unspecified knee

ValidICD-10-CM diagnosis code.

Valid for claims with a date of service in the current code year.

Valid FY2016 onwards.

What has happened to this code

Every change the publisher made, from 2007 to now. Entries marked draft are from the pre-implementation releases: ICD-10 took effect on 1 October 2015, so nothing before FY2016 was ever valid on a claim.

  1. FY2007 Added to the draft code set draft Chronic instability of knee, unspecified knee

Official coding rules

Published by CDC for FY2027. A rule attached to a category binds every code beneath it, so the rules inherited from this code's ancestors are shown with the code they come from.

Inherited from M23 Internal derangement of knee

Excludes1 - never coded here

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

Excludes2 - not included here

  • 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)

Inherited from the M20-M25 section Other joint disorders (M20-M25)

Excludes2 - not included here

  • joints of the spine (M40-M54)

How CDC's index refers to this code

Wording from the official alphabetic index. Much of it appears nowhere in the code description, which is why a search for the everyday phrase so often finds nothing.

Codes in the same group

CodeDescriptionStatus
M23.51 Chronic instability of knee, right knee Valid
M23.52 Chronic instability of knee, left knee Valid