2026 ICD-10-CM Diagnosis Code M71.161Other infective bursitis, right knee

ICD-10-CM Codes›M00–M99›M70-M79›M71

ICD-10-CM M71.161
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M71.161 is a billable ICD-10-CM diagnosis code for other infective bursitis, right knee. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 485 through 487, 557 through 558. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified connective tissue disease.

Code Identity

ICD-10-CM Code
M71.161
Billable Status
Yes — Valid for Submission
Code Describes
Other infective bursitis, right knee
Short Description
Other infective bursitis, right knee
Same as the full description in the CMS dataset.
Parent Code
M71.16
Other infective bursitis, knee

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM70-M79Other soft tissue disorders
CategoryM71Other bursopathies
This CodeM71.161Other infective bursitis, right knee

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral bursitis of knees
  • Bilateral patellar bursitis
  • Bilateral prepatellar bursitis of knees
  • Infection of prepatellar bursa
  • Infection of prepatellar bursa of bilateral knees
  • Infection of prepatellar bursa of left knee
  • Infection of prepatellar bursa of right knee
  • Prepatellar bursitis
  • Prepatellar bursitis of left knee
  • Prepatellar bursitis of right knee

Clinical ClassificationClinical

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

CCSR MUS025
Other specified connective tissue disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Bursitis

A bursa is a small, fluid-filled sac that acts as a cushion between a bone and other moving parts, such as muscles, tendons, or skin. Bursitis occurs when a bursa becomes inflamed. People get bursitis by overusing a joint. It can also be caused by an injury. It usually occurs at the knee or elbow.

Read the full article at MedlinePlus

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

Convert M71.161 to ICD-9-CMHistory

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

ICD-9-CM
727.3 Bursitis NEC
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 M71.161Overview

Is M71.161 (Other infective bursitis, knee) a billable code?

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

What MS-DRG does M71.161 group to?

When other infective bursitis, right knee is the principal diagnosis on an inpatient stay, it groups to MS-DRG 485, 486, 487, 557, 558, with relative weights from 0.8932 to 3.2271 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M71.161?

Under the General Equivalence Mappings, other infective bursitis, right knee converts to ICD-9-CM 727.3 (bursitis NEC). 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.