M23.05 – Cystic meniscus, posterior horn of lateral meniscus

ICD-10-CM 2027 diagnosis code · Other joint disorders

Non-billable header

ICD-10-CM code M23.05

Code: M23.05 (claims format: M2305)
Description: Cystic meniscus, posterior horn of lateral meniscus
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
Block: M20-M25 Other joint disorders
Parent codes: M23 › M23.0

Billable codes under M23.05

M23.05 is a header code and cannot be used on claims. Choose the most specific code:

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

M23 – Internal derangement of knee

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)

Block M20-M25

Excludes2 (not included here):

joints of the spine (M40-M54)

Index terms for M23.05

Entries in the ICD-10-CM alphabetic index that lead to this code:

Derangement, knee, meniscus, cystic, lateral, posterior horn

Related codes in M23.0

Frequently asked questions

What is ICD-10 code M23.05?

M23.05 is the ICD-10-CM code for cystic meniscus, posterior horn of lateral meniscus, in the block M20-M25 (Other joint disorders).

Is M23.05 a billable code?

No. M23.05 is a header code with more specific child codes; report one of the billable codes listed above.

What category does M23.05 belong to?

It belongs to category M23 – Internal derangement of knee.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.