Alphabetic Index FY2027

M23

Internal derangement of knee

FY2027Chapter 13: Diseases of the musculoskeletal system and connective tissue/M20–M25 Other joint disorders

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

M23 is a non-billable ICD-10-CM code category for internal derangement of knee. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are M23.0 Cystic meniscus, M23.2 Derangement of meniscus due to old tear or injury, M23.3 Other meniscus derangements, M23.4 Loose body in knee and 4 more. Its coding notes include 3 Excludes1 entries and 14 Excludes2 entries.

Excludes1

Not coded here. The listed conditions generally should not be reported together.

This code

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

This code
  • 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)
Also from chapter/block level (11 notes)
Inherited from M20–M25 Other joint disorders
Inherited from Chapter 13 Diseases of the musculoskeletal system and connective tissue
  • 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

Also from chapter/block level (1 note)
Inherited from Chapter 13 Diseases of the musculoskeletal system and connective tissue
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

More specific codes under M23 8