2026 ICD-10-CM Diagnosis Code M87.80Other osteonecrosis, unspecified bone

ICD-10-CM Codes›M00–M99›M86-M90›M87

ICD-10-CM M87.80
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M87.80 is a billable ICD-10-CM diagnosis code for other osteonecrosis, unspecified bone. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 553 through 554. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. Coders also document this condition as idiopathic avascular necrosis of bone. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Aseptic necrosis and osteonecrosis.

Code Identity

ICD-10-CM Code
M87.80
Billable Status
Yes — Valid for Submission
Code Describes
Other osteonecrosis, unspecified bone
Short Description
Other osteonecrosis, unspecified bone
Same as the full description in the CMS dataset.
Parent Code
M87.8
Other osteonecrosis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM86-M90Other osteopathies
CategoryM87Osteonecrosis
This CodeM87.80Other osteonecrosis, unspecified bone

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M87.80.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Idiopathic avascular necrosis of bone
  • Osteonecrosis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Osteonecrosis
      • specified type NEC

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MUS030
Aseptic necrosis and osteonecrosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Bisphosphonate-Associated Osteonecrosis of the Jaw

    necrotic jaws or other maxillofacial skeleton necrosis associated with bisphosphonate use (see bisphosphonates). injury, dental procedures, and trauma can trigger the necrotic process.

  • Osteonecrosis

    death of a bone or part of a bone, either atraumatic or posttraumatic.

Patient EducationClinical

Osteonecrosis

Osteonecrosis is a disease caused by reduced blood flow to bones in the joints. In people with healthy bones, new bone is always replacing old bone. In osteonecrosis, the lack of blood causes the bone to break down faster than the body can make enough new bone. The bone starts to die and may break down.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert M87.80 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
733.40 Asept necrosis bone NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M87.80Overview

Is M87.80 (Other osteonecrosis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other osteonecrosis, unspecified bone on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M87.80 group to?

When other osteonecrosis, unspecified bone is the principal diagnosis on an inpatient stay, it groups to MS-DRG 553, 554, with relative weights from 0.8301 to 1.2963 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M87.80?

Under the General Equivalence Mappings, other osteonecrosis, unspecified bone converts to ICD-9-CM 733.40 (asept necrosis bone NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.