2026 ICD-10-CM Diagnosis Code M46.25Osteomyelitis of vertebra, thoracolumbar region

ICD-10-CM Codes›M00–M99›M45-M49›M46

ICD-10-CM M46.25
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M46.25 is a billable ICD-10-CM diagnosis code for osteomyelitis of vertebra, thoracolumbar region. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 456 through 458, 539 through 541. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Osteomyelitis.

Code Identity

ICD-10-CM Code
M46.25
Billable Status
Yes — Valid for Submission
Code Describes
Osteomyelitis of vertebra, thoracolumbar region
Short Description
Osteomyelitis of vertebra, thoracolumbar region
Same as the full description in the CMS dataset.
Parent Code
M46.2
Osteomyelitis of vertebra

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM45-M49Spondylopathies
CategoryM46Other inflammatory spondylopathies
This CodeM46.25Osteomyelitis of vertebra, thoracolumbar region

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.

    • Osteomyelitis(general) (infective) (localized) (neonatal) (purulent) (septic) (staphylococcal) (streptococcal) (suppurative) (with periostitis)
      • vertebra
        • thoracolumbar region

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 M46.25 to ICD-9-CMHistory

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

ICD-9-CM
730.28 Osteomyelit NOS-oth site
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 M46.25Overview

Is M46.25 (Osteomyelitis of vertebra) a billable code?

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

What MS-DRG does M46.25 group to?

When osteomyelitis of vertebra, thoracolumbar region is the principal diagnosis on an inpatient stay, it groups to MS-DRG 456, 457, 458, 539, 540, 541, with relative weights from 0.7715 to 8.4034 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M46.25?

Under the General Equivalence Mappings, osteomyelitis of vertebra, thoracolumbar region converts to ICD-9-CM 730.28 (osteomyelit NOS-oth site). 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.