Is M85.57 a billable ICD-10-CM code?

No. M85.57 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does M85.57 sit in the tabular list?

Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Disorders of bone density and structure (M80-M85).

What cannot be coded together with M85.57?

M85.57 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above M85.57 (M85) and apply to it just the same.

M85.57

M85.57 — Aneurysmal bone cyst, ankle and foot

Non-billable headerICD-10-CM

M85.57 is a non-billable header ICD-10-CM code for aneurysmal bone cyst, ankle and foot. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 inherited from the categories above M85.57

These are not written on M85.57, but they bind it: a note on a category applies to every code beneath it. Billing M85.57 with anything listed here is a denial.

Written on M85 — Other disorders of bone density and structure

osteogenesis imperfecta (Q78.0)
osteopetrosis (Q78.2)
osteopoikilosis (Q78.8)
polyostotic fibrous dysplasia (Q78.1)

Excludes2 inherited from the categories above M85.57

Also inherited, and the opposite of Excludes1: these conditions are not part of M85.57, but a patient can have both, so you may code both.

Written on M85.5 — Aneurysmal bone cyst

aneurysmal cyst of jaw (M27.4)

Risk adjustment

M85.57 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code history

M85.57 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Code to one of these instead M85.57

3 child codes. Green means billable.

Related codes at this level

Codes that share M85.5. If M85.57 is not quite right, the correct code is usually one of these.

Questions about M85.57

Is M85.57 a billable ICD-10-CM code?: No. M85.57 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does M85.57 sit in the tabular list?: Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Disorders of bone density and structure (M80-M85).
What cannot be coded together with M85.57?: M85.57 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above M85.57 (M85) and apply to it just the same.