M23.329 Other meniscus derangements, posterior horn of medial meniscus, unspecified knee

Billable ICD-10-CM code, FY2026.

Applies from M23 Internal derangement of knee

Excludes1 (never code together)

• 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)

Applies from M23.3 Other meniscus derangements

Applicable to

• Degenerate meniscus
• Detached meniscus
• Retained meniscus

MS-DRG index

Defines the logic of DRG(s) 562-563 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 717.2 Derangement of posterior horn of medial meniscus (approximate)

Code annotations containing back-references to M23.329

Back-references to M23

• Type 2 Excludes: M24.1 Other articular cartilage disorders ("internal derangement of knee (M23.-)")
• Type 2 Excludes: S83 Dislocation and sprain of joints and ligaments of knee ("internal derangement of knee (M23.-)")

Nearby codes

• M23.312 Other meniscus derangements, anterior horn of medial meniscus, left knee
• M23.319 Other meniscus derangements, anterior horn of medial meniscus, unspecified knee
• M23.32 Other meniscus derangements, posterior horn of medial meniscus
• M23.321 Other meniscus derangements, posterior horn of medial meniscus, right knee
• M23.322 Other meniscus derangements, posterior horn of medial meniscus, left knee
• M23.329 Other meniscus derangements, posterior horn of medial meniscus, unspecified knee (this code)
• M23.33 Other meniscus derangements, other medial meniscus
• M23.331 Other meniscus derangements, other medial meniscus, right knee
• M23.332 Other meniscus derangements, other medial meniscus, left knee
• M23.339 Other meniscus derangements, other medial meniscus, unspecified knee
• M23.34 Other meniscus derangements, anterior horn of lateral meniscus