M23.31 Other meniscus derangements, anterior horn of medial meniscus

ICD-10-CM Diagnosis Code M23.31: Other Meniscus Derangements, Anterior Horn of Medial Meniscus

ICD-10-CM code M23.31 designates a diagnosis of other meniscus derangements specifically involving the anterior horn of the medial meniscus. This active terminology record is classified as a disease or syndrome and falls under the broader parent category of other meniscus derangements. The supplied sources establish the code's official label and structural hierarchy. 1 3

Plain-language overview

Code M23.31 identifies a health condition classified medically as a disease or syndrome, specifically targeting other meniscus derangements located at the anterior horn of the medial meniscus. 1

What this code represents

The terminology record for M23.31 is currently active and does not contain any narrower subordinate concepts within the ICD-10-CM version 2026 hierarchy. 1

Within the ICD-10-CM coding framework, M23.31 exists as a direct child concept beneath the parent code M23.3, which represents other meniscus derangements. 1

Coding details

Related specific codes include M23.312 for other meniscus derangements of the anterior horn of the medial meniscus in the right knee, and M23.319 for an unspecified knee. 4 5

Documentation considerations

Clinical documentation for conditions involving the medial meniscus may describe associated injuries, as medial meniscus involvement is noted in chronic cases of anterior cruciate ligament ruptures. 2

Coverage and utilization context

A Medicare policy article concerning knee orthoses lists diagnosis codes for other meniscus derangements of the anterior horn of the medial meniscus, including M23.312 for the right knee. 4

What the sources add

The National Cancer Institute terminology record and the EVS Explore database both establish the exact official display label for M23.31 as other meniscus derangements, anterior horn of medial meniscus. 1 3

A clinical reference text adds operational context by describing the medial meniscus anatomy and its association with chronic anterior cruciate ligament injuries, whereas the coding sources focus strictly on terminology. 2 1

Questions to verify

Reviewers may verify whether the clinical documentation specifies the right knee or an unspecified knee, as the supplied sources list M23.312 and M23.319 as related codes. 4 5

Sources

1. ICD-10-CM M23.31 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.
4. Article - Knee Orthoses - Policy Article (A52465) — cms.gov; accessed 2026-07-27.
5. Codigo. The #1 Billing Agency for Medical Practices — codigo.care; accessed 2026-07-27.