ICD-10-CM > M00-M99 > M05-M14 > M13 > M13.1 > M13.16 M13.16 Monoarthritis, not elsewhere classified, knee Non-Billable/Non-Specific Codes M13.161Monoarthritis, not elsewhere classified, right kneeM13.162Monoarthritis, not elsewhere classified, left kneeM13.169Monoarthritis, not elsewhere classified, unspecified knee