2026 ICD-10-CM Diagnosis Code M02.361Reiter's disease, right knee

ICD-10-CM Codes›M00–M99›M00-M02›M02

ICD-10-CM M02.361
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M02.361 is a billable ICD-10-CM diagnosis code for Reiter's disease, right knee. 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 Immune-mediated/reactive arthropathies.

Code Identity

ICD-10-CM Code
M02.361
Billable Status
Yes — Valid for Submission
Code Describes
Reiter's disease, right knee
Short Description
Reiter's disease, right knee
Same as the full description in the CMS dataset.
Parent Code
M02.36
Reiter's disease, knee

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM00-M02Infectious arthropathies
CategoryM02Postinfective and reactive arthropathies
This CodeM02.361Reiter's disease, right knee

Clinical ClassificationClinical

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

CCSR MUS008
Immune-mediated/reactive arthropathies
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 M02.361 to ICD-9-CMHistory

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

ICD-9-CM
099.3 Reiter's disease
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
711.16 Reiter arthritis-l/leg
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 M02.361Overview

Is M02.361 (Reiter's disease, knee) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report Reiter's disease, right knee on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M02.361 group to?

When Reiter's disease, right knee 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 M02.361?

Under the General Equivalence Mappings, Reiter's disease, right knee converts to ICD-9-CM 099.3 (Reiter's disease) and 711.16 (reiter arthritis-l/leg). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.