2026 ICD-10-CM Diagnosis Code M08.20Juvenile rheumatoid arthritis with systemic onset, unspecified site

ICD-10-CM Codes›M00–M99›M05-M14›M08

ICD-10-CM M08.20
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M08.20 is a billable ICD-10-CM diagnosis code for juvenile rheumatoid arthritis with systemic onset, unspecified site. 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 hemophagocytic lymphohistiocytosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Juvenile arthritis.

Code Identity

ICD-10-CM Code
M08.20
Billable Status
Yes — Valid for Submission
Code Describes
Juvenile rheumatoid arthritis with systemic onset, unspecified site
Short Description
Juvenile rheumatoid arthritis with systemic onset, unsp site
Parent Code
M08.2
Juvenile rheumatoid arthritis with systemic onset

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM05-M14Inflammatory polyarthropathies
CategoryM08Juvenile arthritis
This CodeM08.20Juvenile rheumatoid arthritis with systemic onset, unspecified site

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Hemophagocytic lymphohistiocytosis
  • Macrophage activation syndrome
  • Macrophage activation syndrome due to juvenile systemic onset arthritis
  • Systemic onset juvenile chronic arthritis

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.

    • Still's disease or syndrome(juvenile)

Clinical ClassificationClinical

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

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

Clinical InformationClinical

  • Macrophage Activation Syndrome

    a serious complication of childhood systemic inflammatory disorders that is thought to be caused by excessive activation and proliferation of t-lymphocytes and macrophages. it is seen predominantly in children with systemic onset juvenile idiopathic arthritis.

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 M08.20 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 M08.20Overview

Is M08.20 (Juvenile rheumatoid arthritis with systemic onset) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report juvenile rheumatoid arthritis with systemic onset, unspecified site on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M08.20 group to?

When juvenile rheumatoid arthritis with systemic onset, unspecified site 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 M08.20?

Under the General Equivalence Mappings, juvenile rheumatoid arthritis with systemic onset, unspecified site 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.