ICD-10-CM > M00-M99 > M60-M63 > M61 > M61.1 > M61.12 M61.12 Myositis ossificans progressiva, upper arm Non-Billable/Non-Specific Codes M61.121Myositis ossificans progressiva, right upper armM61.122Myositis ossificans progressiva, left upper armM61.129Myositis ossificans progressiva, unspecified upper arm