ICD-10-CM > M00-M99 > M60-M63 > M60 > M60.1 > M60.16 M60.16 Interstitial myositis, lower leg Non-Billable/Non-Specific Codes M60.161Interstitial myositis, right lower legM60.162Interstitial myositis, left lower legM60.169Interstitial myositis, unspecified lower leg