2026 ICD-10-CM Diagnosis Code I34.9Nonrheumatic mitral valve disorder, unspecified

ICD-10-CM Codes›I00–I99›I30-I5A›I34

ICD-10-CM I34.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I34.9 is a billable ICD-10-CM diagnosis code for nonrheumatic mitral valve disorder, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 306 through 307. Coders also document this condition as disorder of mitral valve prosthesis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nonrheumatic and unspecified valve disorders.

This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such nonrheumatic valve disorders - mitral valve disorders.

Code Identity

ICD-10-CM Code
I34.9
Billable Status
Yes — Valid for Submission
Code Describes
Nonrheumatic mitral valve disorder, unspecified
Short Description
Nonrheumatic mitral valve disorder, unspecified
Same as the full description in the CMS dataset.
Parent Code
I34
Nonrheumatic mitral valve disorders

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI30-I5AOther forms of heart disease
CategoryI34Nonrheumatic mitral valve disorders
This CodeI34.9Nonrheumatic mitral valve disorder, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Disorder of mitral valve prosthesis
  • Failure of cardiac valve prosthesis
  • Mitral leaflet abnormality
  • Non-rheumatic mitral valve disease
  • Prosthetic mitral valve failure

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Disease, diseased
      • mitral (valve)
        • nonrheumatic

Clinical ClassificationClinical

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

CCSR CIR003
Nonrheumatic and unspecified valve disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Heart Valve Diseases

Heart valve disease happens when one or more of your heart valves don't work well.

The full article covers:

  • What are heart valve diseases?
  • What are the types of heart valve diseases?
  • What causes heart valve diseases?
  • Who is more likely to develop heart valve diseases?
  • What are the symptoms of heart valve diseases?
  • What other problems can heart valve diseases cause?
  • How is heart valve disease diagnosed?
  • What are the treatments for heart valve diseases?

Read the full article at MedlinePlus

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

Convert I34.9 to ICD-9-CMHistory

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

ICD-9-CM
424.0 Mitral valve disorder
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 I34.9Overview

Is I34.9 (Nonrheumatic mitral valve disorders) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report nonrheumatic mitral valve disorder, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I34.9 group to?

When nonrheumatic mitral valve disorder, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 306, 307, with relative weights from 0.9132 to 1.5758 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I34.9?

Under the General Equivalence Mappings, nonrheumatic mitral valve disorder, unspecified converts to ICD-9-CM 424.0 (mitral valve disorder). 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.