2027 ICD-10-CM Diagnosis Code I01.8Other acute rheumatic heart disease

ICD-10-CM Codes›I00–I99›I00-I02›I01

ICD-10-CM I01.8
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I01.8 is a billable ICD-10-CM diagnosis code for other acute rheumatic heart disease. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 314 through 316. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 46 closely related codes. Coders also document this condition as acute rheumatic carditis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acute rheumatic heart disease and Endocarditis and endocardial disease.

Code Identity

ICD-10-CM Code
I01.8
Billable Status
Yes — Valid for Submission
Code Describes
Other acute rheumatic heart disease
Short Description
Other acute rheumatic heart disease
Same as the full description in the CMS dataset.
Parent Code
Rheumatic fever with heart involvement

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI00-I02Acute rheumatic fever
CategoryI01Rheumatic fever with heart involvement
This CodeI01.8Other acute rheumatic heart disease

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute rheumatic carditis
  • Acute rheumatic fever
  • Acute rheumatic heart disease
  • Acute rheumatic pancarditis
  • MacCallum's patch
  • Pancarditis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I01.8: its own notes plus those printed at I01 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.

  • Any condition in I00 with other or multiple types of heart involvement
  • Acute rheumatic pancarditis

Excludes1

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

From I01 Rheumatic fever with heart involvement applies to 5 codes
  • 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.

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 I01.8, its category, or a range that includes it.

Applicable To 1

These notes mention I01.8.

  • I02.0 Rheumatic chorea with heart involvement
    Rheumatic chorea with heart involvement of any type classifiable under I01.- names I01.-, which includes this code

Excludes1 1

These codes carry an Excludes1 note naming I01.8: they are not reported together with it, unless the two conditions are unrelated.

  • I00 Rheumatic fever without heart involvement
    rheumatic fever with heart involvement (I01.0 -I01.9) names I01.0 -I01.9, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming I01.8: 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

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR CIR002
Acute rheumatic heart disease
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR CIR004
Endocarditis and endocardial disease
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

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Read the full article at MedlinePlus

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

Convert I01.8 to ICD-9-CMHistory

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

ICD-9-CM
391.8 Ac rheumat hrt dis NEC
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I01.8Overview

What is the ICD-10 code for other acute rheumatic heart disease?

The ICD-10-CM code for other acute rheumatic heart disease is I01.8 (sometimes written as I018). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I01.8 (Rheumatic fever with heart involvement) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other acute rheumatic heart disease on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does I01.8 group to?

When other acute rheumatic heart disease is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 316, 315, with relative weights from 0.6678 to 2.0871 depending on complications. Higher weights mean higher Medicare reimbursement.

Is I01.8 a CC or MCC?

CMS lists I01.8 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 46 closely related codes in its exclusion list.

What is the ICD-9 equivalent of I01.8?

Under the General Equivalence Mappings, other acute rheumatic heart disease converts to ICD-9-CM 391.8 (ac rheumat hrt dis NEC). The mapping is a direct match.