M23.8X9 – Other internal derangements of unspecified knee

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

Billable code

ICD-10-CM code M23.8X9

Code: M23.8X9 (claims format: M238X9)
Description: Other internal derangements of unspecified knee
Billable: Yes – valid for HIPAA-covered transactions
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 › M23.8 › M23.8X

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)

M23.8 – Other internal derangements of knee

Applicable to:

Laxity of ligament of knee
Snapping knee

Block M20-M25

Excludes2 (not included here):

joints of the spine (M40-M54)

Related codes in M23.8X

Frequently asked questions

What is ICD-10 code M23.8X9?

M23.8X9 is the ICD-10-CM code for other internal derangements of unspecified knee, in the block M20-M25 (Other joint disorders).

Is M23.8X9 a billable code?

Yes. M23.8X9 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does M23.8X9 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.