M89.78 – Major osseous defect, other site

ICD-10-CM 2027 diagnosis code · Other osteopathies

Billable code

ICD-10-CM code M89.78
Code
M89.78 (claims format: M8978)
Description
Major osseous defect, other site
Billable
Yes – valid for HIPAA-covered transactions
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
Block
M86-M90 Other osteopathies
Parent codes
M89 › M89.7

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

M89.7 – Major osseous defect

Code first:
  • underlying disease, if known, such as:
  • aseptic necrosis of bone (M87.-)
  • malignant neoplasm of bone (C40.-)
  • osteolysis (M89.5-)
  • osteomyelitis (M86.-)
  • osteonecrosis (M87.-)
  • osteoporosis (M80.-, M81.-)
  • periprosthetic osteolysis (T84.05-)

Block M86-M90

Excludes1 (not coded here):
  • postprocedural osteopathies (M96.-)

Index terms for M89.78

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in M89.7

Frequently asked questions

What is ICD-10 code M89.78?

M89.78 is the ICD-10-CM code for major osseous defect, other site, in the block M86-M90 (Other osteopathies).

Is M89.78 a billable code?

Yes. M89.78 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does M89.78 belong to?

It belongs to category M89 – Other disorders of bone.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.