2026 ICD-10-CM Diagnosis Code M02.839Other reactive arthropathies, unspecified wrist

ICD-10-CM Codes›M00–M99›M00-M02›M02

ICD-10-CM M02.839
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M02.839 is a billable ICD-10-CM diagnosis code for other reactive arthropathies, unspecified wrist. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 548 through 550. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 942 closely related codes. The code is a manifestation code that cannot be reported as the principal diagnosis and flagged as an unspecified code, since codes identifying laterality exist in the same family. Coders also document this condition as reactive arthritis of distal radioulnar joint. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Immune-mediated/reactive arthropathies.

For Medicare Advantage risk adjustment, M02.839 maps to CMS-HCC Category 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis) under the V28 model, adding a risk factor of about 0.479 for a community, non-dual, aged beneficiary in payment year 2026.

Code Identity

ICD-10-CM Code
M02.839
Billable Status
Yes — Valid for Submission
Code Describes
Other reactive arthropathies, unspecified wrist
Short Description
Other reactive arthropathies, unspecified wrist
Same as the full description in the CMS dataset.
Parent Code
M02.83
Other reactive arthropathies, wrist

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM00-M02Infectious arthropathies
CategoryM02Postinfective and reactive arthropathies
This CodeM02.839Other reactive arthropathies, unspecified wrist

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M02.839.

Manifestation diagnoses
Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.
Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Medicare Risk Adjustment (HCC)Billing

M02.839 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 92— Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis
Payment HCC · PY 2026 one of 609 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.479
community, non-dual, aged · ranges 0.471–0.632 across segments
Hierarchy
Top of its hierarchy
HCC 92 is not superseded by any other condition category
Prior Model (CMS-HCC V24)
HCC 39
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 39 · ESRD (V21): HCC 39 · ESRD (V24): HCC 39
ESRD V21 weights: 0.061 dialysis, 0.375–0.468 functioning graft · ESRD V24 weights: 0.092 dialysis, 0.431–0.578 functioning graft
Part D (RxHCC)
Not mapped
M02.839 does not risk-adjust in the RxHCC prescription drug model

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.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Reactive arthritis of distal radioulnar joint
  • Reactive arthritis of joint of wrist region
  • Reactive arthritis of radiocarpal joint

Clinical ClassificationClinical

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

CCSR MUS008
Immune-mediated/reactive arthropathies
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Infectious Arthritis

Most kinds of arthritis cause pain and swelling in your joints. Joints are places where two bones meet, such as your elbow or knee. Infectious arthritis is an infection in the joint. The infection comes from a bacterial, viral, or fungal infection that spreads from another part of the body. Symptoms of infectious arthritis include:

Read the full article at MedlinePlus

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

Convert M02.839 to ICD-9-CMHistory

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

ICD-9-CM
711.43 Bact arthritis-forearm
Approximate The match is approximate rather than exact.
ICD-9-CM
711.53 Viral arthritis-forearm
Approximate The match is approximate rather than exact.
ICD-9-CM
711.83 Inf arthrit NEC-forearm
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 M02.839Overview

What is the ICD-10 code for other reactive arthropathies, unspecified wrist?

The ICD-10-CM code for other reactive arthropathies, unspecified wrist is M02.839 (sometimes written as M02839). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is M02.839 (Other reactive arthropathies, wrist) a billable code?

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

What MS-DRG does M02.839 group to?

On inpatient claims, other reactive arthropathies, unspecified wrist maps to MS-DRG 548, 549, 550, with relative weights from 0.8741 to 1.9309 depending on complications. Higher weights mean higher Medicare reimbursement.

Is M02.839 a CC or MCC?

CMS lists M02.839 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 942 closely related codes in its exclusion list.

Can M02.839 be a principal diagnosis?

No. This is a manifestation code: other reactive arthropathies, unspecified wrist describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.

What HCC is M02.839?

M02.839 (other reactive arthropathies, unspecified wrist) maps to CMS-HCC Category 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis), commonly written as HCC 92, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 39 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.

Does M02.839 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, M02.839 adds a risk adjustment factor of about 0.479 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.471 to 0.632 depending on the payment segment). HCC 92 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 92 category page.