2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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 2027 (October 1, 2026 through September 30, 2027) 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I34.9: its own notes plus those printed at I34 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From I34 Nonrheumatic mitral valve disorders applies to 6 codes
  • mitral valve disease (I05.9)
  • mitral valve failure (I05.8)
  • mitral valve stenosis (I05.0)
  • mitral valve disorder of unspecified cause with diseases of aortic and/or tricuspid valve(s) (I08.-)
  • mitral valve disorder of unspecified cause with mitral stenosis or obstruction (I05.0)
  • mitral valve disorder specified as congenital (Q23.2, Q23.9)
  • mitral valve disorder specified as rheumatic (I05.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I34.9, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming I34.9: they are not reported together with it, unless the two conditions are unrelated.

  • I05 Rheumatic mitral valve diseases
    mitral valve disease specified as nonrheumatic (I34.-) names I34.-, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming I34.9: its condition is not part of those codes, and both may be reported when the patient has both.

  • I08 Multiple valve diseases
    multiple valve disease specified as nonrheumatic (I34.-, I35.-, I36.-, I37.-, I38.-, Q22.-, Q23.-, Q24.8-) names I34.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I34.9Overview

What is the ICD-10 code for nonrheumatic mitral valve disorder, unspecified?

The ICD-10-CM code for nonrheumatic mitral valve disorder, unspecified is I34.9 (sometimes written as I349). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 0.9146 to 1.5457 depending on complications. Higher weights mean higher Medicare reimbursement.

Can I34.9 be reported with I05.9?

Not as a rule. The Excludes1 note at I34, which applies to I34.9, lists "mitral valve disease (I05.9)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

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.