2027 ICD-10-CM Diagnosis Code I35.9Nonrheumatic aortic valve disorder, unspecified

ICD-10-CM Codes›I00–I99›I30-I5A›I35

ICD-10-CM I35.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I35.9 is a billable ICD-10-CM diagnosis code for nonrheumatic aortic 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 abnormality of aortic valve. 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 - aortic valve disorders.

Code Identity

ICD-10-CM Code
I35.9
Billable Status
Yes — Valid for Submission
Code Describes
Nonrheumatic aortic valve disorder, unspecified
Short Description
Nonrheumatic aortic valve disorder, unspecified
Same as the full description in the CMS dataset.
Parent Code
I35
Nonrheumatic aortic valve disorders

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI30-I5AOther forms of heart disease
CategoryI35Nonrheumatic aortic valve disorders
This CodeI35.9Nonrheumatic aortic valve disorder, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormality of aortic valve
  • Aortic valve disease during pregnancy
  • Aortic valve disorder
  • Aortic valve disorder in mother complicating childbirth
  • Heart disease in mother complicating childbirth
  • Heart disease in mother complicating pregnancy, childbirth AND/OR puerperium

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I35.9: its own notes plus those printed at I35 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

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 I35 Nonrheumatic aortic valve disorders applies to 5 codes
  • aortic valve disorder of unspecified cause but with diseases of mitral and/or tricuspid valve(s) (I08.-)
  • aortic valve disorder specified as congenital (Q23.0, Q23.1)
  • aortic valve disorder specified as rheumatic (I06.-)
  • hypertrophic subaortic stenosis (I42.1)
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.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From I35 Nonrheumatic aortic valve disorders applies to 5 codes
  • if applicable, bicuspid aortic valve (Q23.81)

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I35.9, its category, or a range that includes it.

Excludes2 2

These codes carry an Excludes2 note naming I35.9: its condition is not part of those codes, and both may be reported when the patient has both.

  • I06 Rheumatic aortic valve diseases
    aortic valve disease not specified as rheumatic (I35.-) names I35.-, which includes this code
  • I08 Multiple valve diseases
    multiple valve disease specified as nonrheumatic (I34.-, I35.-, I36.-, I37.-, I38.-, Q22.-, Q23.-, Q24.8-) names I35.-, which includes this code

Code First 1

These codes say to code first a condition named in the note, and I35.9 is one of the conditions named.

  • I5A Non-ischemic myocardial injury (non-traumatic)
    nonrheumatic aortic valve disorders (I35.-) names I35.-, 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 I35.9 to ICD-9-CMHistory

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

ICD-9-CM
424.1 Aortic 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 I35.9Overview

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

The ICD-10-CM code for nonrheumatic aortic valve disorder, unspecified is I35.9 (sometimes written as I359). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I35.9 (Nonrheumatic aortic valve disorders) a billable code?

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

What MS-DRG does I35.9 group to?

When nonrheumatic aortic 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.

What is the ICD-9 equivalent of I35.9?

Under the General Equivalence Mappings, nonrheumatic aortic valve disorder, unspecified converts to ICD-9-CM 424.1 (aortic valve disorder). The mapping is approximate, so confirm the match fits the documentation.