2027 ICD-10-CM Diagnosis Code I01.1Acute rheumatic endocarditis
ICD-10-CM Codes›I00–I99›I00-I02›I01
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Chronic Condition
I01.1 is a billable ICD-10-CM diagnosis code for acute rheumatic endocarditis. 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. 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 78 closely related codes. Coders also document this condition as acute rheumatic aortitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acute rheumatic heart disease and Endocarditis and endocardial disease.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute rheumatic aortitis
- Acute rheumatic carditis
- Acute rheumatic endocarditis
- Acute rheumatic fever
- Acute rheumatic heart disease
- Acute rheumatic valvulitis
- Endocarditis associated with another disorder
- Rheumatoid aortitis
- Rheumatoid arteritis
- Secondary aortitis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to I01.1: 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 endocarditis or valvulitis
- Acute rheumatic valvulitis
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- 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 I01.1, its category, or a range that includes it.
Applicable To 1
These notes mention I01.1.
Excludes1 2
These codes carry an Excludes1 note naming I01.1: they are not reported together with it, unless the two conditions are unrelated.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular) I38
Stenosis, stenotic (cicatricial) See Also: Stricture;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Acute Rheumatic Endocarditis
inflammation of the endocardium in acute rheumatic heart disease.
Patient EducationClinical
Endocarditis
Endocarditis is sometimes called infective endocarditis. It's a rare but life-threatening inflammation of the lining inside your heart's chambers and valves (the endocardium).
The full article covers:
- What is endocarditis?
- What causes endocarditis?
- Who is more likely to develop endocarditis?
- What are the symptoms of endocarditis?
- What other problems can endocarditis cause?
- How is endocarditis diagnosed?
- What are the treatments for endocarditis?
- Can endocarditis be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I01.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I01.1Overview
What is the ICD-10 code for acute rheumatic endocarditis?
The ICD-10-CM code for acute rheumatic endocarditis is I01.1 (sometimes written as I011). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is I01.1 (Rheumatic fever with heart involvement) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report acute rheumatic endocarditis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does I01.1 group to?
When acute rheumatic endocarditis 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.
Is I01.1 a CC or MCC?
CMS lists I01.1 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 78 closely related codes in its exclusion list.
What is the ICD-9 equivalent of I01.1?
Under the General Equivalence Mappings, acute rheumatic endocarditis converts to ICD-9-CM 391.1 (acute rheumatic endocard). The mapping is a direct match.
