2026 ICD-10-CM Diagnosis Code M00.839Arthritis due to other bacteria, unspecified wrist

ICD-10-CM Codes›M00–M99›M00-M02›M00

ICD-10-CM M00.839
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M00.839 is a billable ICD-10-CM diagnosis code for arthritis due to other bacteria, 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 448 closely related codes. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. Coders also document this condition as pyogenic bacterial arthritis of wrist. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Infective arthritis.

For Medicare Advantage risk adjustment, M00.839 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
M00.839
Billable Status
Yes — Valid for Submission
Code Describes
Arthritis due to other bacteria, unspecified wrist
Short Description
Arthritis due to other bacteria, unspecified wrist
Same as the full description in the CMS dataset.
Parent Code
M00.83
Arthritis due to other bacteria, wrist

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM00-M02Infectious arthropathies
CategoryM00Pyogenic arthritis
This CodeM00.839Arthritis due to other bacteria, unspecified wrist

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M00.839.

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

M00.839 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
M00.839 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.

  • Pyogenic bacterial arthritis of wrist
  • Suppurative arthritis caused by bacteria
  • Wrist pyogenic arthritis

Clinical ClassificationClinical

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

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR MUS001
Infective arthritis
Default principal diagnosis: inpatient Yes · outpatient Yes

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 M00.839 to ICD-9-CMHistory

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

ICD-9-CM
711.03 Pyogen arthritis-forearm
Approximate The match is approximate rather than exact.
ICD-9-CM
711.03 Pyogen arthritis-forearm
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
041.89 Oth specf bacteria
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

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 M00.839Overview

What is the ICD-10 code for arthritis due to other bacteria, unspecified wrist?

The ICD-10-CM code for arthritis due to other bacteria, unspecified wrist is M00.839 (sometimes written as M00839). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is M00.839 (Arthritis due to other bacteria, wrist) a billable code?

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

What MS-DRG does M00.839 group to?

When arthritis due to other bacteria, unspecified wrist is the principal diagnosis on an inpatient stay, it groups 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 M00.839 a CC or MCC?

CMS lists M00.839 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 448 closely related codes in its exclusion list.

What is the ICD-9 equivalent of M00.839?

Under the General Equivalence Mappings, arthritis due to other bacteria, unspecified wrist converts to ICD-9-CM 711.03 (pyogen arthritis-forearm), 711.03 (pyogen arthritis-forearm), and 041.89 (oth specf bacteria). The mapping is approximate, so confirm the match fits the documentation.

What HCC is M00.839?

M00.839 (arthritis due to other bacteria, 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 M00.839 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, M00.839 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.