Alphabetic Index FY2027

M85.5

Aneurysmal bone cyst

FY2027Chapter 13: Diseases of the musculoskeletal system and connective tissue/M80–M85 Disorders of bone density and structure

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

M85.5 is a non-billable ICD-10-CM code header for aneurysmal bone cyst. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are 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 and 6 more. Its coding notes include 4 Excludes1 entries and 11 Excludes2 entries.

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from M85 Other disorders of bone density and structure
  • osteogenesis imperfecta (Q78.0)
  • osteopetrosis (Q78.2)
  • osteopoikilosis (Q78.8)
  • polyostotic fibrous dysplasia (Q78.1)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

This code
  • aneurysmal cyst of jaw (M27.4)
Also from chapter/block level (10 notes)
Inherited from Chapter 13 Diseases of the musculoskeletal system and connective tissue
  • arthropathic psoriasis (L40.5-)
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • compartment syndrome (traumatic) (T79.A-)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Notes

Also from chapter/block level (1 note)
Inherited from Chapter 13 Diseases of the musculoskeletal system and connective tissue
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

More specific codes under M85.5 10