2026 ICD-10-CM Diagnosis Code M15.9Polyosteoarthritis, unspecified

ICD-10-CM Codes›M00–M99›M15-M19›M15

ICD-10-CM M15.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M15.9 is a billable ICD-10-CM diagnosis code for polyosteoarthritis, 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. Coders also document this condition as degenerative polyarthritis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Osteoarthritis.

Code Identity

ICD-10-CM Code
M15.9
Billable Status
Yes — Valid for Submission
Code Describes
Polyosteoarthritis, unspecified
Short Description
Polyosteoarthritis, unspecified
Same as the full description in the CMS dataset.
Parent Code
M15
Polyosteoarthritis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM15-M19Osteoarthritis
CategoryM15Polyosteoarthritis
This CodeM15.9Polyosteoarthritis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Degenerative polyarthritis
  • Generalized osteoarthritis
  • Generalized osteoarthritis of the hand
  • Osteoarthritis of multiple joints
  • Small and large joint arthritis

Tabular List NotesGuidance

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

Inclusion Terms

  • Generalized osteoarthritis 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.

    • Atrophy, atrophic(of)
      • polyarthritis
    • Disease, diseased
      • joint
        • degenerative
          • multiple
    • Osteoarthritis
      • generalized (multiple joints)
    • Osteoarthritis
      • primary
        • multiple sites
    • Osteoarthrosis(degenerative) (hypertrophic) (joint)
      • generalized
    • Osteoarthrosis(degenerative) (hypertrophic) (joint)
      • polyarticular
    • Polyarthrosis
    • Polyosteoarthritis

Clinical ClassificationClinical

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

CCSR MUS006
Osteoarthritis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Osteoarthritis

Osteoarthritis, sometimes called OA, is a type of arthritis that only affects the joints, usually in the hands, knees, hips, neck, and lower back. It's the most common type of arthritis.

The full article covers:

  • What is osteoarthritis?
  • What are the symptoms of osteoarthritis?
  • What causes osteoarthritis?
  • Who is more likely to develop osteoarthritis?
  • How is osteoarthritis diagnosed?
  • What are the treatments for osteoarthritis?

Read the full article at MedlinePlus

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

Convert M15.9 to ICD-9-CMHistory

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

ICD-9-CM
715.00 General osteoarthrosis
Approximate The match is approximate rather than exact.
ICD-9-CM
715.90 Osteoarthros NOS-unspec
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 M15.9Overview

Is M15.9 (Polyosteoarthritis) a billable code?

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

What MS-DRG does M15.9 group to?

When polyosteoarthritis, 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 M15.9?

Under the General Equivalence Mappings, polyosteoarthritis, unspecified converts to ICD-9-CM 715.00 (general osteoarthrosis) and 715.90 (osteoarthros NOS-unspec). 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.