2026 ICD-10-CM Diagnosis Code M87.9Osteonecrosis, unspecified

ICD-10-CM Codes›M00–M99›M86-M90›M87

ICD-10-CM M87.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M87.9 is a billable ICD-10-CM diagnosis code for osteonecrosis, unspecified. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Aseptic necrosis and osteonecrosis.

Code Identity

ICD-10-CM Code
M87.9
Billable Status
Yes — Valid for Submission
Code Describes
Osteonecrosis, unspecified
Short Description
Osteonecrosis, unspecified
Same as the full description in the CMS dataset.
Parent Code
M87
Osteonecrosis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM86-M90Other osteopathies
CategoryM87Osteonecrosis
This CodeM87.9Osteonecrosis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute osteonecrosis
  • Avascular necrosis of capitellum
  • Avascular necrosis of metatarsal bone
  • Avascular necrosis of tarsus
  • Bilateral osteonecrosis of humeri
  • Osteonecrosis of bone of bilateral elbow regions
  • Osteonecrosis of bone of elbow region
  • Osteonecrosis of bone of left ankle region
  • Osteonecrosis of bone of left elbow region
  • Osteonecrosis of bone of left foot
  • Osteonecrosis of bone of right ankle region
  • Osteonecrosis of bone of right elbow region
  • Osteonecrosis of bone of right foot
  • Osteonecrosis of carpal bone of left wrist
  • Osteonecrosis of carpal bone of right wrist
  • Osteonecrosis of femoral condyle
  • Osteonecrosis of humerus
  • Osteonecrosis of jaw
  • Osteonecrosis of lateral femoral condyle
  • Osteonecrosis of left humerus
  • Osteonecrosis of left lateral femoral condyle
  • Osteonecrosis of left lunate
  • Osteonecrosis of left talus
  • Osteonecrosis of lunate
  • Osteonecrosis of metatarsal of left foot
  • Osteonecrosis of metatarsal of right foot
  • Osteonecrosis of right humerus
  • Osteonecrosis of right lateral femoral condyle
  • Osteonecrosis of right lunate
  • Osteonecrosis of right talus
  • Osteonecrosis of talus

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Necrosis of bone NOS

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.

    • Necrosis, necrotic(ischemic)
      • bone
    • Osteonecrosis

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.

  • Aseptic Necrosis of Bone

    necrosis of bone due to an inadequate blood supply.

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 M87.9 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 M87.9Overview

Is M87.9 (Osteonecrosis) a billable code?

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

What MS-DRG does M87.9 group to?

When osteonecrosis, unspecified 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 M87.9?

Under the General Equivalence Mappings, osteonecrosis, unspecified 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.