M23.5
Non-billableChronic instability of knee
Chronic instability of knee
This is a header/category code. For billing purposes, use a more specific child code from the list below.
Coding Notes
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
Excludes 2
Conditions not included here, but the patient may have both
- •arthropathic psoriasisL40.5
- •certain conditions originating in the perinatal periodP04-P96
- •certain infectious and parasitic diseasesA00-B99
- •compartment syndrome (traumatic)A-)T79
- •complications of pregnancy, childbirth and the puerperiumO9A)O00
- •congenital malformations, deformations, and chromosomal abnormalitiesQ00-Q99
- •endocrine, nutritional and metabolic diseasesE00-E88
- •injury, poisoning and certain other consequences of external causesS00-T88
- •neoplasmsC00-D49
- •symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classifiedR00-R94
- •joints of the spineM40-M54
- •current injury - see injury of knee and lower legS80-S89
- •recurrent dislocation or subluxation of jointsM24.4
- •recurrent dislocation or subluxation of patellaM22.0-M22.1
Child Codes (3)
Related Codes(7)
ICD-11 Equivalents(1)
ICD-11 Equivalents
View full mappingCorresponding ICD-11 codes from the WHO crosswalk mapping
Also Known As / Clinical Terms(3)
Frequently Asked Questions
What is the ICD-10 code for chronic instability of knee?
The ICD-10-CM code for chronic instability of knee is M23.5. The full clinical description is "Chronic instability of knee". M23.5 is a non-billable header code. Use a more specific child code for billing purposes.
What does ICD-10 code M23.5 mean?
ICD-10-CM code M23.5 represents “Chronic instability of knee”. It is classified under Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue and is a non-billable header code. Use a more specific child code for billing purposes.
Is M23.5 a billable code?
No, M23.5 is a non-billable header code. You need to use one of its more specific child codes for billing. There are 3 child codes under M23.5.
What chapter is M23.5 in?
M23.5 is in Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue (codes M00-M99).
What codes cannot be used with M23.5?
M23.5 has Excludes1 notes indicating codes that cannot be used together with it, including: ankylosis (M24.66); deformity of knee (M21.-); osteochondritis dissecans (M93.2).
What are the subcategories under M23.5?
M23.5 has 3 child codes, including: M23.50 (Chronic instability of knee, unspecified knee), M23.51 (Chronic instability of knee, right knee), M23.52 (Chronic instability of knee, left knee).
What are the UMLS CUIs for M23.5?
M23.5 is linked to 1 UMLS Concept Unique Identifier: C0451820. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does M23.5 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like chronic instability of knee affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of M23.5?
M23.5 maps to the ICD-11 code: FA33.4Z (Chronic instability of knee, unspecified).
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.