M23.50
Billable codeChronic instability of knee, unspecified knee
The ICD-10 code for chronic instability of knee, unspecified knee is M23.50.
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •This code describes an unspecified presentation. If the medical record documents a more specific detail (e.g. laterality, type, or affected site), a more specific sibling code should be used instead — see Related codes below.
- •Laterality-specific codes exist for this condition — confirm the affected side is documented.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- M23.51Chronic instability of knee, right knee
- M23.52Chronic instability of knee, left knee
- M23.50Chronic instability of knee, unspecified knee
ICD-9-CM equivalent
Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.
- 71785Approximate match
- 71886Approximate match
- 71781Approximate match
- 71782Approximate match
- 71783Approximate match
- 71784Approximate match
Associated MS-DRGs
M23.50 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.
Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.