2026 ICD-10-CM Diagnosis Code M08.89Other juvenile arthritis, multiple sites

ICD-10-CM Codes›M00–M99›M05-M14›M08

ICD-10-CM M08.89
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M08.89 is a billable ICD-10-CM diagnosis code for other juvenile arthritis, multiple sites. 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.

For Medicare Advantage risk adjustment, M08.89 maps to CMS-HCC Category 93 (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders) under the V28 model, adding a risk factor of about 0.617 for a community, non-dual, aged beneficiary in payment year 2026.

Code Identity

ICD-10-CM Code
M08.89
Billable Status
Yes — Valid for Submission
Code Describes
Other juvenile arthritis, multiple sites
Short Description
Other juvenile arthritis, multiple sites
Same as the full description in the CMS dataset.
Parent Code
M08.8
Other juvenile arthritis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM05-M14Inflammatory polyarthropathies
CategoryM08Juvenile arthritis
This CodeM08.89Other juvenile arthritis, multiple sites

Medicare Risk Adjustment (HCC)Billing

M08.89 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.

CMS-HCC V28 Category (Payment Model)
HCC 93— Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders
Payment HCC · PY 2026 one of 508 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.617
community, non-dual, aged · ranges 0.288–0.617 across segments
Hierarchy
Supersedes HCC 94
less severe related categories are not paid alongside HCC 93
Prior Model (CMS-HCC V24)
HCC 40
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 40 · ESRD (V21): HCC 40 · ESRD (V24): HCC 40
ESRD V21 weights: 0.072 dialysis, 0.274–0.398 functioning graft · ESRD V24 weights: 0.058 dialysis, 0.284–0.414 functioning graft
Part D (RxHCC)
RxHCC 83 — Rheumatoid Arthritis and Other Inflammatory Polyarthropathy
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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 M08.89 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 M08.89Overview

What is the ICD-10 code for other juvenile arthritis, multiple sites?

The ICD-10-CM code for other juvenile arthritis, multiple sites is M08.89 (sometimes written as M0889). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is M08.89 (Other juvenile arthritis) a billable code?

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

What MS-DRG does M08.89 group to?

When other juvenile arthritis, multiple sites 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 M08.89?

Under the General Equivalence Mappings, other juvenile arthritis, multiple sites converts to ICD-9-CM 714.30 (juv rheum arthritis NOS). The mapping is approximate, so confirm the match fits the documentation.

What HCC is M08.89?

M08.89 (other juvenile arthritis, multiple sites) maps to CMS-HCC Category 93 (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders), commonly written as HCC 93, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 40 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 83.

Does M08.89 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, M08.89 adds a risk adjustment factor of about 0.617 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.288 to 0.617 depending on the payment segment). HCC 93 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 93 category page.