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M23

Non-billable

Internal derangement of knee

M23 is the ICD-10-CM code for Internal derangement of knee. It is a non-billable category code — use a more specific child code such as M23.0 for billing.

Status
Header (non-billable)
Chapter
M00-M99
Subcodes
8
Edition
FY2026

M00-M99 Diseases of the musculoskeletal system and connective tissue

Excludes1 — not 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)

Frequently asked questions

What is ICD-10 code M23?
M23 is the ICD-10-CM code for "Internal derangement of knee". It falls under M00-M99 Diseases of the musculoskeletal system and connective tissue.
Is M23 a billable code?
No — M23 is a non-billable header code. Use a more specific child code (such as M23.0) for billing.
What are the subcodes of M23?
M23 has 8 more specific child codes, including M23.0, M23.2, M23.3.
What is excluded from M23?
Excludes1 (not coded here): ankylosis (M24.66); deformity of knee (M21.-); osteochondritis dissecans (M93.2).

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

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