ICD-10-CM > M00-M99 > M20-M25 > M23 > M23.9 M23.9 Unspecified internal derangement of knee Non-Billable/Non-Specific Codes M23.90Unspecified internal derangement of unspecified kneeM23.91Unspecified internal derangement of right kneeM23.92Unspecified internal derangement of left knee