2026 ICD-10-CM Diagnosis Code I09.9Rheumatic heart disease, unspecified

ICD-10-CM Codes›I00–I99›I05-I09›I09

ICD-10-CM I09.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I09.9 is a billable ICD-10-CM diagnosis code for rheumatic heart disease, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. Coders also document this condition as carditis due to rheumatic fever. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chronic rheumatic heart disease and Endocarditis and endocardial disease.

Code Identity

ICD-10-CM Code
I09.9
Billable Status
Yes — Valid for Submission
Code Describes
Rheumatic heart disease, unspecified
Short Description
Rheumatic heart disease, 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 CodeI09.9Rheumatic heart disease, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carditis due to rheumatic fever
  • Chronic rheumatic carditis
  • Recurrent rheumatic heart disease
  • Rheumatic heart disease
  • Rheumatic heart valve failure

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Rheumatic carditis

Type 1 Excludes

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
      • heart (organic)
        • with
          • rheumatic fever (conditions in I00)
            • inactive or quiescent (with chorea)
    • Disease, diseased
      • heart (organic)
        • rheumatic (chronic) (inactive) (old) (quiescent) (with chorea)
    • Failure, failed
      • heart (acute) (senile) (sudden)
        • rheumatic (chronic) (inactive)
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • rheumatic (active) (acute) (chronic) (subacute)
        • inactive or quiescent with
          • carditis
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • rheumatic (active) (acute) (chronic) (subacute)
        • inactive or quiescent with
          • pancarditis

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
CCSR CIR004
Endocarditis and endocardial disease
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Rheumatic Heart Disease

    cardiac manifestation of systemic rheumatological conditions, such as rheumatic fever. rheumatic heart disease can involve any part the heart, most often the heart valves and the endocardium.

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 I09.9 to ICD-9-CMHistory

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

ICD-9-CM
398.90 Rheumatic heart dis NOS
Exact Match The mapping is direct, with no qualifiers.

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 I09.9Overview

Is I09.9 (Other rheumatic heart diseases) a billable code?

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

What MS-DRG does I09.9 group to?

When rheumatic heart disease, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I09.9?

Under the General Equivalence Mappings, rheumatic heart disease, unspecified converts to ICD-9-CM 398.90 (rheumatic heart dis NOS). The mapping is a direct match.

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.