M85.5 ICD-10-CA subcategory: Aneurysmal bone cyst
M85.5 isn’t a code on its own. Choose one of the 10 codes beneath it, the one the documentation supports.
Official description
M85.5Aneurysmal bone cyst
ICD-10-CA · Canada · Also written M855
Codes in M85.5
M85.5 isn’t a code on its own. Open the code that matches what the note documents.
M85.50Aneurysmal bone cyst, multiple sitesM85.51Aneurysmal bone cyst, shoulder regionM85.52Aneurysmal bone cyst, upper armM85.53Aneurysmal bone cyst, forearmM85.54Aneurysmal bone cyst, handM85.55Aneurysmal bone cyst, pelvic region and thighM85.56Aneurysmal bone cyst, lower legM85.57Aneurysmal bone cyst, ankle and footM85.58Aneurysmal bone cyst, other siteM85.59Aneurysmal bone cyst, unspecified siteNotes for M85.5
As CIHI prints them, with any note M85.5 takes from the headings above it.
Excludes
Conditions classified elsewhere.
- Aneurysmal cyst of jaw (K09.2)
- Osteogenesis imperfecta (Q78.0)osteopetrosis (Q78.2)osteopoikilosis (Q78.8)polyostotic fibrous dysplasia (Q78.1)From M85 Other disorders of bone density and structure
- Certain:• conditions originating in the perinatal period (P00-P96)• disorders of the temporomandibular joint (K07.6)• infectious and parasitic diseases (A00-B99)compartment syndrome (T79.6)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)From Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
Note
- [To review the anatomical site captured in the 5th character subclassification see Chapter XIII]
- The following fifth characters represent the following sites of involvement:0 Multiple sites1 Shoulder region: clavical , scapula — joint acromioclavicular, glenohumeral, sternoclavicular2 Upper arm: humerus — elbow joint,3 Forearm: radius , ulna — wrist joint,4 Hand: carpus, fingers, metacarpus — joints between these bones,5 Pelvic region and thigh: buttock , femur , pelvis — joint hip , sacroiliac6 Lower leg: fibula , tibia — knee joint7 Ankle and foot: metatarsus, tarsus, toes — other joints in foot8 Other:head neck ribs skull trunk vertebral column9 Site unspecifiedFrom Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
Where M85.5 sits
- 1ChapterChapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
- 2Block M80-M94Osteopathies and chondropathies
- 3Block M80-M85Disorders of bone density and structure
- 4Category M85Other disorders of bone density and structure
- 5Subcategory M85.5Aneurysmal bone cyst
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
Is M85.5 a valid ICD-10-CA code?
No. M85.5 (Aneurysmal bone cyst) is a subcategory heading in CIHI’s ICD-10-CA FY 2026–2027 release. It holds 10 codes; record the one the documentation supports.
Where is M85.5 in ICD-10-CA?
M85.5 sits under M85 Other disorders of bone density and structure, within M80-M85 Disorders of bone density and structure, within M80-M94 Osteopathies and chondropathies, within Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99).
What coding notes apply to M85.5?
ICD-10-CA lists Note, Excludes notes for M85.5, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.