ICD-10-CM > M00-M99 > M80-M85 > M85 > M85.5 > M85.57 M85.57 Aneurysmal bone cyst, ankle and foot Non-Billable/Non-Specific Codes M85.571Aneurysmal bone cyst, right ankle and footM85.572Aneurysmal bone cyst, left ankle and footM85.579Aneurysmal bone cyst, unspecified ankle and foot