2026 ICD-10-CM Diagnosis Code M86.8X7Other osteomyelitis, ankle and foot

ICD-10-CM Codes›M00–M99›M86-M90›M86

ICD-10-CM M86.8X7
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M86.8X7 is a billable ICD-10-CM diagnosis code for other osteomyelitis, ankle and foot. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 539 through 541. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Osteomyelitis.

Code Identity

ICD-10-CM Code
M86.8X7
Billable Status
Yes — Valid for Submission
Code Describes
Other osteomyelitis, ankle and foot
Short Description
Other osteomyelitis, ankle and foot
Same as the full description in the CMS dataset.
Parent Code
M86.8X
Other osteomyelitis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM86-M90Other osteopathies
CategoryM86Osteomyelitis
This CodeM86.8X7Other osteomyelitis, ankle and foot

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral ankle periostitis
  • Bilateral foot periostitis
  • Osteomyelitis of ankle AND/OR foot
  • Osteomyelitis of bilateral ankles
  • Osteomyelitis of bilateral feet
  • Osteomyelitis of foot
  • Osteomyelitis of left ankle
  • Osteomyelitis of left foot
  • Osteomyelitis of right ankle
  • Osteomyelitis of right foot
  • Periostitis of ankle
  • Periostitis of ankle and foot
  • Periostitis of foot
  • Periostitis of left ankle
  • Periostitis of left foot
  • Periostitis of right ankle
  • Periostitis of right foot

Clinical ClassificationClinical

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

CCSR MUS002
Osteomyelitis
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Osteomyelitis

    inflammation of the bone as a result of infection. it may be caused by a variety of infectious agents, especially pyogenic (pus - producing) bacteria.

Patient EducationClinical

Bone Infections

Like other parts of the body, bones can get infected. The infections are usually bacterial, but can also be fungal. They may spread to the bone from nearby skin or muscles, or from another part of the body through the bloodstream.

Read the full article at MedlinePlus

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

Convert M86.8X7 to ICD-9-CMHistory

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

ICD-9-CM
730.17 Chr osteomyelit-ankle
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 M86.8X7Overview

Is M86.8X7 (Other osteomyelitis) a billable code?

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

What MS-DRG does M86.8X7 group to?

When other osteomyelitis, ankle and foot is the principal diagnosis on an inpatient stay, it groups to MS-DRG 539, 540, 541, with relative weights from 0.7715 to 1.9697 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M86.8X7?

Under the General Equivalence Mappings, other osteomyelitis, ankle and foot converts to ICD-9-CM 730.17 (chr osteomyelit-ankle). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.