2027 ICD-10-CM Diagnosis Code I34.1Nonrheumatic mitral (valve) prolapse

ICD-10-CM Codes›I00–I99›I30-I5A›I34

ICD-10-CM I34.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I34.1 is a billable ICD-10-CM diagnosis code for nonrheumatic mitral (valve) prolapse. 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. 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
I34.1
Billable Status
Yes — Valid for Submission
Code Describes
Nonrheumatic mitral (valve) prolapse
Short Description
Nonrheumatic mitral (valve) prolapse
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 CodeI34.1Nonrheumatic mitral (valve) prolapse

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arrhythmogenic bileaflet mitral prolapse
  • Degenerative mitral valve prolapse
  • Familial mitral valve prolapse
  • Hypogonadism with mitral valve prolapse and intellectual disability syndrome
  • Mitral cusp prolapse
  • Mitral valve anterior leaflet prolapse
  • Mitral valve posterior leaflet prolapse
  • Mitral valve prolapse
  • Mitral valve prolapse syndrome
  • Non-rheumatic mitral valve disease
  • Non-rheumatic mitral valve prolapse
  • Rheumatic mitral valve prolapse

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I34.1: 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.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Floppy nonrheumatic mitral valve syndrome

Excludes1

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

On I34.1 itself
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 I34.1, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming I34.1: 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 I34.1: 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

Mitral Valve Prolapse

The mitral valve is one of the four valves in your heart. Heart valves have flaps that open and close. The flaps make sure that blood flows in the right direction through your heart and to the rest of your body. When your heart beats, the flaps open to let blood through.

The full article covers:

  • What is the mitral valve?
  • What is mitral valve prolapse (MVP)?
  • Who is more likely to develop mitral valve prolapse (MVP)?
  • What are the symptoms of mitral valve prolapse (MVP)?
  • What other problems can mitral valve prolapse (MVP) cause?
  • How is mitral valve prolapse (MVP) diagnosed?
  • What are the treatments for mitral valve prolapse (MVP)?
  • Can mitral valve prolapse be prevented?

Read the full article at MedlinePlus

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

Convert I34.1 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 I34.1Overview

What is the ICD-10 code for nonrheumatic mitral (valve) prolapse?

The ICD-10-CM code for nonrheumatic mitral (valve) prolapse is I34.1 (sometimes written as I341). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I34.1 (Nonrheumatic mitral valve disorders) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report nonrheumatic mitral (valve) prolapse on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does I34.1 group to?

When nonrheumatic mitral (valve) prolapse 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 I34.1 be reported with a code from Q87.4?

Not as a rule. The Excludes1 note on I34.1 lists "Marfan's syndrome (Q87.4-)". 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 I34.1?

Under the General Equivalence Mappings, nonrheumatic mitral (valve) prolapse converts to ICD-9-CM 424.0 (mitral valve disorder). The mapping is approximate, so confirm the match fits the documentation.