ICD-10-CM 2027 diagnosis code
I01.2Acute rheumatic myocarditis
I01.2 is a valid, billable ICD-10-CM code for acute rheumatic myocarditis. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About I01.2
I01.2 is the ICD-10-CM diagnosis code for acute rheumatic myocarditis. It belongs to category I01 (rheumatic fever with heart involvement), block I00-I02 (acute rheumatic fever) and chapter 9 (diseases of the circulatory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within I01 (rheumatic fever with heart involvement), I01.2 is specifically for acute rheumatic myocarditis. Related codes cover acute rheumatic pericarditis (I01.0), acute rheumatic endocarditis (I01.1), other acute rheumatic heart disease (I01.8) and acute rheumatic heart disease, unspecified (I01.9).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 314 (Other Circulatory System Diagnoses with MCC, relative weight 2.0873), DRG 315 (Other Circulatory System Diagnoses with CC, relative weight 0.9508) and DRG 316 (Other Circulatory System Diagnoses without CC/MCC, relative weight 0.6677), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 391.2 (acute rheumatic myocarditis).
Coding notes
- Any condition in I00 with myocarditis
Notes that apply from higher levels
Instructions written at a parent level also apply to I01.2.
Broader instructions also apply from Chapter 9: Diseases of the circulatory system.
Alphabetic index entries
8 entriesTerms in the official ICD-10-CM index that lead to I01.2.
- Degeneration, degenerative › myocardial, myocardium (fatty) (hyaline) (senile) › with rheumatic fever (conditions in I00) › active, acute or subacute
- Insufficiency, insufficient › myocardial, myocardium (with arteriosclerosis) › with › rheumatic fever (conditions in I00) › active, acute or subacute
- Insufficiency, insufficient › myocardial, myocardium (with arteriosclerosis) › rheumatic › active, acute, or subacute
- Myocarditis (with arteriosclerosis)(chronic)(fibroid) (interstitial) (old) (progressive) (senile) › active › rheumatic
- Myocarditis (with arteriosclerosis)(chronic)(fibroid) (interstitial) (old) (progressive) (senile) › acute or subacute (interstitial) › due to › streptococcus (beta-hemolytic)
- Myocarditis (with arteriosclerosis)(chronic)(fibroid) (interstitial) (old) (progressive) (senile) › acute or subacute (interstitial) › rheumatic
- Myocarditis (with arteriosclerosis)(chronic)(fibroid) (interstitial) (old) (progressive) (senile) › rheumatic (chronic) (inactive) (with chorea) › active or acute
- Rheumatic (acute) (subacute) › myocarditis (chronic) (inactive) (with chorea) › active or acute
Codes whose notes reference I01.2
- I40Excludes1
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 05 · Diseases and Disorders of the Circulatory System
ICD-9-CM equivalent
Converter →- 391.2Acute rheumatic myocarditisexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about I01.2
Is I01.2 billable?
- Yes. I01.2 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I01.2 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I01.2 as a principal diagnosis.
Is I01.2 a CC or MCC?
- I01.2 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does I01.2 group to?
- I01.2 is used in the MS-DRG v44.0 logic for MS-DRG 314 (Other Circulatory System Diagnoses with MCC), MS-DRG 315 (Other Circulatory System Diagnoses with CC) and MS-DRG 316 (Other Circulatory System Diagnoses without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for I01.2?
- The CMS General Equivalence Mappings map I01.2 to ICD-9-CM 391.2.