2026 ICD-10-CM Diagnosis Code M86.339Chronic multifocal osteomyelitis, unspecified radius and ulna

ICD-10-CM Codes›M00–M99›M86-M90›M86

ICD-10-CM M86.339
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M86.339 is a billable ICD-10-CM diagnosis code for chronic multifocal osteomyelitis, unspecified radius and ulna. 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. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Osteomyelitis.

Code Identity

ICD-10-CM Code
M86.339
Billable Status
Yes — Valid for Submission
Code Describes
Chronic multifocal osteomyelitis, unspecified radius and ulna
Short Description
Chronic multifocal osteomyelitis, unsp radius and ulna
Parent Code
M86.33
Chronic multifocal osteomyelitis, radius and ulna

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM86-M90Other osteopathies
CategoryM86Osteomyelitis
This CodeM86.339Chronic multifocal osteomyelitis, unspecified radius and ulna

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M86.339.

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.

Clinical ClassificationClinical

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

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

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 M86.339 to ICD-9-CMHistory

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

ICD-9-CM
730.13 Chr osteomyelit-forearm
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 M86.339Overview

Is M86.339 (Chronic multifocal osteomyelitis, radius and ulna) a billable code?

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

What MS-DRG does M86.339 group to?

When chronic multifocal osteomyelitis, unspecified radius and ulna 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 M86.339?

Under the General Equivalence Mappings, chronic multifocal osteomyelitis, unspecified radius and ulna converts to ICD-9-CM 730.13 (chr osteomyelit-forearm). 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.