2026 ICD-10-CM Diagnosis Code M05.842Other rheumatoid arthritis with rheumatoid factor of left hand

ICD-10-CM Codes›M00–M99›M05-M14›M05

ICD-10-CM M05.842
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M05.842 is a billable ICD-10-CM diagnosis code for other rheumatoid arthritis with rheumatoid factor of left hand. 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 bilateral rheumatoid arthritis of hands. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Rheumatoid arthritis and related disease.

This medical diagnosis code is frequently used in Orthopedics medical specialties to designate conditions such rheumatoid arthritis.

Code Identity

ICD-10-CM Code
M05.842
Billable Status
Yes — Valid for Submission
Code Describes
Other rheumatoid arthritis with rheumatoid factor of left hand
Short Description
Oth rheumatoid arthritis with rheumatoid factor of left hand
Parent Code
M05.84
Other rheumatoid arthritis with rheumatoid factor of hand

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM05-M14Inflammatory polyarthropathies
CategoryM05Rheumatoid arthritis with rheumatoid factor
This CodeM05.842Other rheumatoid arthritis with rheumatoid factor of left hand

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral rheumatoid arthritis of hands
  • Rheumatoid arthritis of left hand
  • Rheumatoid arthritis of right hand
  • Seropositive rheumatoid arthritis of bilateral hands
  • Seropositive rheumatoid arthritis of left hand

Clinical ClassificationClinical

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

CCSR MUS003
Rheumatoid arthritis and related disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a form of arthritis that causes pain, swelling, and stiffness in your joints. RA is an autoimmune disease. Although it is most common in the wrist and fingers, this disease can cause your immune system to attack any joint tissue. The inflammation (swelling) that comes with RA can also affect other body parts.

The full article covers:

  • What is rheumatoid arthritis?
  • Who is more likely to get rheumatoid arthritis?
  • What causes rheumatoid arthritis?
  • What are the symptoms of rheumatoid arthritis?
  • How is rheumatoid arthritis diagnosed?
  • What are the treatments for rheumatoid arthritis?

Read the full article at MedlinePlus

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

Convert M05.842 to ICD-9-CMHistory

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

ICD-9-CM
714.0 Rheumatoid arthritis
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 M05.842Overview

Is M05.842 (Other rheumatoid arthritis with rheumatoid factor of hand) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other rheumatoid arthritis with rheumatoid factor of left hand on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M05.842 group to?

When other rheumatoid arthritis with rheumatoid factor of left hand 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 M05.842?

Under the General Equivalence Mappings, other rheumatoid arthritis with rheumatoid factor of left hand converts to ICD-9-CM 714.0 (rheumatoid arthritis). 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.