2026 ICD-10-CM Diagnosis Code M08.979Juvenile arthritis, unspecified, unspecified ankle and foot

ICD-10-CM Codes›M00–M99›M05-M14›M08

ICD-10-CM M08.979
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M08.979 is a billable ICD-10-CM diagnosis code for juvenile arthritis, unspecified, unspecified 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 545 through 547. Coders also document this condition as arthritis of joint of toe. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Juvenile arthritis.

Code Identity

ICD-10-CM Code
M08.979
Billable Status
Yes — Valid for Submission
Code Describes
Juvenile arthritis, unspecified, unspecified ankle and foot
Short Description
Juvenile arthritis, unspecified, unspecified ankle and foot
Same as the full description in the CMS dataset.
Parent Code
M08.97
Juvenile arthritis, unspecified, ankle and foot

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM05-M14Inflammatory polyarthropathies
CategoryM08Juvenile arthritis
This CodeM08.979Juvenile arthritis, unspecified, unspecified ankle and foot

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arthritis of joint of toe
  • Arthritis of midtarsal joint
  • Inflammation of metatarsophalangeal joint

Clinical ClassificationClinical

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

CCSR MUS004
Juvenile arthritis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Juvenile Arthritis

Juvenile arthritis (JA) is arthritis that happens in children. It causes joint inflammation (swelling), pain, stiffness, and loss of motion. Joints are places where two bones meet, such as your elbow or knee. It can affect any joint, but it is more common in the knees, hands, and feet.

The full article covers:

  • What is juvenile arthritis?
  • Who is more likely to get juvenile arthritis?
  • What causes juvenile arthritis?
  • What are the symptoms of juvenile arthritis?
  • How is juvenile arthritis diagnosed?
  • What are the treatments for juvenile arthritis?

Read the full article at MedlinePlus

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

Convert M08.979 to ICD-9-CMHistory

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

ICD-9-CM
714.30 Juv rheum arthritis 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 M08.979Overview

Is M08.979 (Juvenile arthritis, unspecified, ankle and foot) a billable code?

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

What MS-DRG does M08.979 group to?

When juvenile arthritis, unspecified, unspecified ankle and foot is the principal diagnosis on an inpatient stay, it groups to MS-DRG 545, 546, 547, with relative weights from 0.8362 to 2.4817 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M08.979?

Under the General Equivalence Mappings, juvenile arthritis, unspecified, unspecified ankle and foot converts to ICD-9-CM 714.30 (juv rheum arthritis 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.