ICD-10-CM > M00-M99 > M60-M63 > M61 > M61.1 > M61.13 M61.13 Myositis ossificans progressiva, forearm Non-Billable/Non-Specific Codes M61.131Myositis ossificans progressiva, right forearmM61.132Myositis ossificans progressiva, left forearmM61.139Myositis ossificans progressiva, unspecified forearm