2026 ICD-10-CM Diagnosis Code M67.51Plica syndrome, right knee

ICD-10-CM Codes›M00–M99›M65-M67›M67

ICD-10-CM M67.51
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M67.51 is a billable ICD-10-CM diagnosis code for plica syndrome, right knee. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 557 through 558. Coders also document this condition as synovial plica. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Tendon and synovial disorders.

Code Identity

ICD-10-CM Code
M67.51
Billable Status
Yes — Valid for Submission
Code Describes
Plica syndrome, right knee
Short Description
Plica syndrome, right knee
Same as the full description in the CMS dataset.
Parent Code
M67.5
Plica syndrome

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM65-M67Disorders of synovium and tendon
CategoryM67Other disorders of synovium and tendon
This CodeM67.51Plica syndrome, right knee

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Synovial plica
  • Synovial plica of knee
  • Synovial plica syndrome of bilateral knees
  • Synovial plica syndrome of left knee
  • Synovial plica syndrome of right knee

Clinical ClassificationClinical

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

CCSR MUS009
Tendon and synovial disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Knee Injuries and Disorders

Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty walking.

Read the full article at MedlinePlus

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

Convert M67.51 to ICD-9-CMHistory

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

ICD-9-CM
727.83 Plica syndrome
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 M67.51Overview

Is M67.51 (Plica syndrome) a billable code?

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

What MS-DRG does M67.51 group to?

When plica syndrome, right knee is the principal diagnosis on an inpatient stay, it groups to MS-DRG 557, 558, with relative weights from 0.8932 to 1.4869 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M67.51?

Under the General Equivalence Mappings, plica syndrome, right knee converts to ICD-9-CM 727.83 (plica syndrome). 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.