2026 ICD-10-CM Diagnosis Code M23.049Cystic meniscus, anterior horn of lateral meniscus, unspecified knee

ICD-10-CM Codes›M00–M99›M20-M25›M23

ICD-10-CM M23.049
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M23.049 is a billable ICD-10-CM diagnosis code for cystic meniscus, anterior horn of lateral meniscus, unspecified knee. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 562 through 563. Coders also document this condition as cyst of anterior horn of lateral meniscus of knee. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified joint disorders.

Code Identity

ICD-10-CM Code
M23.049
Billable Status
Yes — Valid for Submission
Code Describes
Cystic meniscus, anterior horn of lateral meniscus, unspecified knee
Short Description
Cystic meniscus, anterior horn of lat mensc, unsp knee
Parent Code
M23.04
Cystic meniscus, anterior horn of lateral meniscus

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM20-M25Other joint disorders
CategoryM23Internal derangement of knee
This CodeM23.049Cystic meniscus, anterior horn of lateral meniscus, unspecified knee

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cyst of anterior horn of lateral meniscus of knee
  • Cyst of lateral meniscus

Clinical ClassificationClinical

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

CCSR MUS007
Other specified joint 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 M23.049 to ICD-9-CMHistory

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

ICD-9-CM
717.42 Derange ant lat meniscus
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 M23.049Overview

Is M23.049 (Cystic meniscus, anterior horn of lateral meniscus) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report cystic meniscus, anterior horn of lateral meniscus, unspecified knee on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M23.049 group to?

When cystic meniscus, anterior horn of lateral meniscus, unspecified knee is the principal diagnosis on an inpatient stay, it groups to MS-DRG 562, 563, with relative weights from 0.8955 to 1.4248 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M23.049?

Under the General Equivalence Mappings, cystic meniscus, anterior horn of lateral meniscus, unspecified knee converts to ICD-9-CM 717.42 (derange ant lat meniscus). 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.