ICD-10-CM > M00-M99 > M05-M14 > M12 > M12.2 > M12.26 M12.26 Villonodular synovitis (pigmented), knee Non-Billable/Non-Specific Codes M12.261Villonodular synovitis (pigmented), right kneeM12.262Villonodular synovitis (pigmented), left kneeM12.269Villonodular synovitis (pigmented), unspecified knee