2027 ICD-10-CM Diagnosis Code I09.1Rheumatic diseases of endocardium, valve unspecified

ICD-10-CM Codes›I00–I99›I05-I09›I09

ICD-10-CM I09.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I09.1 is a billable ICD-10-CM diagnosis code for rheumatic diseases of endocardium, valve 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chronic rheumatic heart disease.

Code Identity

ICD-10-CM Code
I09.1
Billable Status
Yes — Valid for Submission
Code Describes
Rheumatic diseases of endocardium, valve unspecified
Short Description
Rheumatic diseases of endocardium, valve unspecified
Same as the full description in the CMS dataset.
Parent Code
I09
Other rheumatic heart diseases

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI05-I09Chronic rheumatic heart diseases
CategoryI09Other rheumatic heart diseases
This CodeI09.1Rheumatic diseases of endocardium, valve unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carditis due to rheumatic fever
  • Chronic endocarditis
  • Chronic rheumatic carditis
  • Chronic rheumatic endocarditis
  • Chronic rheumatic valvulitis
  • Chronic valvulitis
  • Endocarditis associated with another disorder
  • Rheumatic disease of heart valve
  • Rheumatic heart valve regurgitation
  • Rheumatic heart valve stenosis
  • Rheumatic heart valve stenosis with insufficiency

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I09.1: its own notes plus those printed at 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.

  • Rheumatic endocarditis (chronic)
  • Rheumatic valvulitis (chronic)

Excludes1

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

  • endocarditis, valve unspecified (I38)

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 I09.1, its category, or a range that includes it.

Excludes1 3

These codes carry an Excludes1 note naming I09.1: they are not reported together with it, unless the two conditions are unrelated.

  • I08 Multiple valve diseases
    rheumatic valve disease NOS (I09.1)
  • I38 Endocarditis, valve unspecified
    endocarditis specified as rheumatic (I09.1)
  • I01 Rheumatic fever with heart involvement
    chronic diseases of rheumatic origin (I05-I09) unless rheumatic fever is also present or there is evidence of reactivation or activity of the rheumatic process. names I05-I09, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming I09.1: its condition is not part of those codes, and both may be reported when the patient has both.

  • I51 Complications and ill-defined descriptions of heart disease
    heart disease specified as rheumatic (I00-I09) names I00-I09, 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 CIR001
Chronic rheumatic heart disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Acute Rheumatic Endocarditis

    inflammation of the endocardium in acute rheumatic heart disease.

Patient EducationClinical

Heart Diseases

Heart disease is a general term that includes many types of heart problems. It's a type of cardiovascular disease, which means heart and blood vessel disease.

The full article covers:

  • What is heart disease?
  • What are the types of heart disease?
  • What causes heart diseases?
  • Who is more likely to develop heart diseases?
  • What are the symptoms of heart disease?
  • How are heart diseases diagnosed?
  • What are the treatments for heart disease?
  • Can heart diseases be prevented?

Read the full article at MedlinePlus

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

Convert I09.1 to ICD-9-CMHistory

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

ICD-9-CM
397.9 Rheum endocarditis NOS
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 I09.1Overview

What is the ICD-10 code for rheumatic diseases of endocardium, valve unspecified?

The ICD-10-CM code for rheumatic diseases of endocardium, valve unspecified is I09.1 (sometimes written as I091). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I09.1 (Other rheumatic heart diseases) a billable code?

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

What MS-DRG does I09.1 group to?

When rheumatic diseases of endocardium, valve 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 I09.1 be reported with I38?

Not as a rule. The Excludes1 note on I09.1 lists "endocarditis, valve unspecified (I38)". 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 I09.1?

Under the General Equivalence Mappings, rheumatic diseases of endocardium, valve unspecified converts to ICD-9-CM 397.9 (rheum endocarditis NOS). The mapping is approximate, so confirm the match fits the documentation.