M23
Header — not billableInternal derangement of knee
The ICD-10 code for internal derangement of knee is M23.
M23 is a non-billable header code. It groups related conditions but cannot be used on its own for reimbursement — select one of the 8 more specific codes below.
Clinical notes
Excludes1 (not coded here)
An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).
Excludes2 (not included here)
An Excludes2 note means the excluded condition is not part of this one, but a patient can have both at the same time — in that case both codes may be reported together.
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •This is a non-billable header code. Documentation must support a more specific child code before this diagnosis can be reported on a claim.
- •Confirm the excluded condition(s) listed above are not also present — Excludes1 conditions cannot be coded together with this one.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Child codes under M23
- M23.0Cystic meniscusnon-billable header
- M23.2Derangement of meniscus due to old tear or injurynon-billable header
- M23.3Other meniscus derangementsnon-billable header
- M23.4Loose body in kneenon-billable header
- M23.5Chronic instability of kneenon-billable header
- M23.6Other spontaneous disruption of ligament(s) of kneenon-billable header
- M23.8Other internal derangements of kneenon-billable header
- M23.9Unspecified internal derangement of kneenon-billable header
Related codes in this category
- M20Acquired deformities of fingers and toesnon-billable header
- M21Other acquired deformities of limbsnon-billable header
- M22Disorder of patellanon-billable header
- M24Other specific joint derangementsnon-billable header
- M25Other joint disorder, not elsewhere classifiednon-billable header
- M23Internal derangement of kneenon-billable header