ICD-10-CM > M00-M99 > M20-M25 > M23 > M23.0 > M23.05 M23.05 Cystic meniscus, posterior horn of lateral meniscus Non-Billable/Non-Specific Codes M23.051Cystic meniscus, posterior horn of lateral meniscus, right kneeM23.052Cystic meniscus, posterior horn of lateral meniscus, left kneeM23.059Cystic meniscus, posterior horn of lateral meniscus, unspecified knee