ICD-10-CM > M00-M99 > M65-M67 > M65 > M65.8 > M65.86 M65.86 Other synovitis and tenosynovitis, lower leg Non-Billable/Non-Specific Codes M65.861Other synovitis and tenosynovitis, right lower legM65.862Other synovitis and tenosynovitis, left lower legM65.869Other synovitis and tenosynovitis, unspecified lower leg