M85.5
Aneurysmal bone cyst
Not billable — category only FY2026 2025-10-01 → 2026-09-30
Exclusions 15 never code together
M85code
M00-M99chapter
Excludes2
- arthropathic psoriasis (L40.5-)L40.5-
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- compartment syndrome (traumatic) (T79.A-)T79.A-
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 1
M00-M99chapter
Notes
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Index entries leading here filed at null
No alphabetic index entry points at this code.
Alongside this code 8 same parent — M85
M85.0 Fibrous dysplasia (monostotic) category M85.1 Skeletal fluorosis category M85.2 Hyperostosis of skull M85.3 Osteitis condensans category M85.4 Solitary bone cyst category M85.6 Other cyst of bone category M85.8 Other specified disorders of bone density and structure category M85.9 Disorder of bone density and structure, unspecified
Subordinate codes 10
M85.50 Aneurysmal bone cyst, unspecified site M85.51 Aneurysmal bone cyst, shoulder M85.52 Aneurysmal bone cyst, upper arm M85.53 Aneurysmal bone cyst, forearm M85.54 Aneurysmal bone cyst, hand M85.55 Aneurysmal bone cyst, thigh M85.56 Aneurysmal bone cyst, lower leg M85.57 Aneurysmal bone cyst, ankle and foot M85.58 Aneurysmal bone cyst, other site M85.59 Aneurysmal bone cyst, multiple sites
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.