ICD-10-CM > M00-M99 > M80-M85 > M85 > M85.5 > M85.53 M85.53 Aneurysmal bone cyst, forearm Non-Billable/Non-Specific Codes M85.531Aneurysmal bone cyst, right forearmM85.532Aneurysmal bone cyst, left forearmM85.539Aneurysmal bone cyst, unspecified forearm