2026 ICD-10-CM Diagnosis Code M08.4APauciarticular juvenile rheumatoid arthritis, other specified site

ICD-10-CM Codes›M00–M99›M05-M14›M08

ICD-10-CM M08.4A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M08.4A is a billable ICD-10-CM diagnosis code for pauciarticular juvenile rheumatoid arthritis, other specified 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Juvenile arthritis.

Code Identity

ICD-10-CM Code
M08.4A
Billable Status
Yes — Valid for Submission
Code Describes
Pauciarticular juvenile rheumatoid arthritis, other specified site
Short Description
Pauciarticular juvenile rheumatoid arthritis, oth site
Parent Code
M08.4
Pauciarticular juvenile rheumatoid arthritis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM05-M14Inflammatory polyarthropathies
CategoryM08Juvenile arthritis
This CodeM08.4APauciarticular juvenile rheumatoid arthritis, other specified site

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.

    • Arthritis, arthritic(acute) (chronic) (nonpyogenic) (subacute)
      • juvenile
        • pauciarticular
          • specified site NEC

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.

Code History & ChangesHistory

Replacement M08.4A replaces the following previously assigned code(s):

  • M08.40 - Pauciarticular juvenile rheumatoid arthritis, unsp site
FY 2021AddedAdded to the ICD-10-CM code setEffective October 1, 2020.
FY 2022–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M08.4AOverview

Is M08.4A (Pauciarticular juvenile rheumatoid arthritis) a billable code?

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

What MS-DRG does M08.4A group to?

When pauciarticular juvenile rheumatoid arthritis, other specified 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.

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.