ICD-10-CM > M00-M99 > M05-M14 > M08 > M08.2 > M08.26 M08.26 Juvenile rheumatoid arthritis with systemic onset, knee Non-Billable/Non-Specific Codes M08.261Juvenile rheumatoid arthritis with systemic onset, right kneeM08.262Juvenile rheumatoid arthritis with systemic onset, left kneeM08.269Juvenile rheumatoid arthritis with systemic onset, unspecified knee