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I09.0 ICD-10-CM Code: Rheumatic myocarditis

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 Excludes1

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 314 — OTHER CIRCULATORY SYSTEM DIAGNOSES WITH MCC (MDC 05)
  • MS-DRG 315 — OTHER CIRCULATORY SYSTEM DIAGNOSES WITH CC (MDC 05)
  • MS-DRG 316 — OTHER CIRCULATORY SYSTEM DIAGNOSES WITHOUT CC/MCC (MDC 05)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I09.0 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Coder workflow for I09.0

MedCoder structured workflow — derived from this code’s own official record

Before you code I09.0

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with I09.0. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in I09.0’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewI51.4

Consider I09.0. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Official instructions as workflow

  • Excludes1 — check before selecting I09.0(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with I09.0: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareI51.4

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition I09.0 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewI51.4

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Rheumatic myocarditis is a billable ICD-10-CM diagnosis code (I09.0).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (12)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name I09.0 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: I01 — Rheumatic fever with heart involvement (via I09.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 1 Excludes2 note: I51 — Complications and ill-defined descriptions of heart disease (via I09.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 26 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 3 MS-DRGs: DRG 314 (MDC 05), DRG 315 (MDC 05), DRG 316 (MDC 05).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):CIR001 — Chronic rheumatic heart disease (default); CIR005 — Myocarditis and cardiomyopathy.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

I00 — Rheumatic fever without heart involvement, I01.2 — Acute rheumatic myocarditis, I01.8 — Other acute rheumatic heart disease, I01.9 — Acute rheumatic heart disease, unspecified, I09.9 — Rheumatic heart disease, unspecified, I23.0 — Hemopericardium as current complication following acute myocardial infarction, I23.1 — Atrial septal defect as current complication following acute myocardial infarction, I23.2 — Ventricular septal defect as current complication following acute myocardial infarction, I23.3 — Rupture of cardiac wall without hemopericardium as current complication following acute myocardial infarction, I23.6 — Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction, I23.7 — Postinfarction angina, I23.8 — Other current complications following acute myocardial infarction, I27.841 — Fontan-associated lymphatic dysfunction, I27.848 — Other Fontan-associated condition, I27.849 — Fontan related circulation, unspecified, I40.0 — Infective myocarditis, I40.1 — Isolated myocarditis, I40.8 — Other acute myocarditis, I40.9 — Acute myocarditis, unspecified, I51.0 — Cardiac septal defect, acquired, +5 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Chronic rheumatic heart disease, Myocarditis and cardiomyopathy).

I07.1 — Rheumatic tricuspid insufficiency, I07.2 — Rheumatic tricuspid stenosis and insufficiency, I07.8 — Other rheumatic tricuspid valve diseases, I07.9 — Rheumatic tricuspid valve disease, unspecified, I08.0 — Rheumatic disorders of both mitral and aortic valves, I08.1 — Rheumatic disorders of both mitral and tricuspid valves, I08.2 — Rheumatic disorders of both aortic and tricuspid valves, I08.3 — Combined rheumatic disorders of mitral, aortic and tricuspid valves, I08.8 — Other rheumatic multiple valve diseases, I08.9 — Rheumatic multiple valve disease, unspecified, I09.1 — Rheumatic diseases of endocardium, valve unspecified, I09.2 — Chronic rheumatic pericarditis, I09.81 — Rheumatic heart failure, I09.89 — Other specified rheumatic heart diseases, I09.9 — Rheumatic heart disease, unspecified, I25.5 — Ischemic cardiomyopathy, I40.0 — Infective myocarditis, I40.1 — Isolated myocarditis, I40.8 — Other acute myocarditis, I40.9 — Acute myocarditis, unspecified, +38 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Insufficiency, insufficient”, “Cardiomyopathy”, “Degeneration, degenerative”, …; these codes share that main term but sit in a different category of the Tabular List.

I06.9 — Rheumatic aortic valve disease, unspecified (rheumatic, inactive or quiescent with, endocarditis, aortic), I07.1 — Rheumatic tricuspid insufficiency (tricuspid), I07.2 — Rheumatic tricuspid stenosis and insufficiency (tricuspid, with, obstruction or stenosis), I07.8 — Other rheumatic tricuspid valve diseases (rheumatic, inactive or quiescent with, endocarditis, tricuspid), I07.9 — Rheumatic tricuspid valve disease, unspecified (tricuspid), I08.0 — Rheumatic disorders of both mitral and aortic valves (aortic, with, mitraldisease), I08.1 — Rheumatic disorders of both mitral and tricuspid valves (tricuspid, with, mitraldisease), I08.2 — Rheumatic disorders of both aortic and tricuspid valves (aortic, with, tricuspiddisease), I08.3 — Combined rheumatic disorders of mitral, aortic and tricuspid valves (mitral, with, tricuspiddisease, with aorticdisease), I08.8 — Other rheumatic multiple valve diseases (pulmonary, valve, rheumatic, with aortic, mitral or tricuspiddisease), I13.2 — Hypertensive heart and chronic kidney disease with heart failure and with stage 5 chronic kidney disease, or end stage renal disease (cardiorenal, hypertensive), I24.89 — Other forms of acute ischemic heart disease (coronary), I25.5 — Ischemic cardiomyopathy (ischemic), I25.89 — Other forms of chronic ischemic heart disease (coronary, chronic or with a stated duration of over 4 weeks), I34.0 — Nonrheumatic mitral (valve) insufficiency (mitral), I35.1 — Nonrheumatic aortic (valve) insufficiency (aortic), I35.2 — Nonrheumatic aortic (valve) stenosis with insufficiency (aortic, with, stenosis), I36.1 — Nonrheumatic tricuspid (valve) insufficiency (tricuspid, nonrheumatic), I36.2 — Nonrheumatic tricuspid (valve) stenosis with insufficiency (tricuspid, nonrheumatic, with stenosis), I37.1 — Nonrheumatic pulmonary valve insufficiency (pulmonary, valve), +373 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of I09.0 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run I09.0 with these 3 related codes in Claim Check

Hierarchy

Excludes1

Referenced by Excludes1 notes

  • I01 — Rheumatic fever with heart involvement[Excludes1](via I09.-): “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.”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 05 — Diseases and Disorders of the Circulatory System[MDC crossing]: “Diseases and Disorders of the Circulatory System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 17,209 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries (12)

  • Cardiomyopathy (familial) (idiopathic), rheumatic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Degeneration, degenerative, myocardial, myocardium (fatty) (hyaline) (senile), with rheumatic fever (conditions in I00)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Degeneration, degenerative, myocardial, myocardium (fatty) (hyaline) (senile), with rheumatic fever (conditions in I00), inactive or quiescent (with chorea)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor), rheumatic (active) (acute) (chronic) (subacute), inactive or quiescent with, myocarditis, myocardial degeneration (conditions in I51.4)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Insufficiency, insufficient, myocardial, myocardium (with arteriosclerosis), rheumatic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Insufficiency, insufficient, myocardial, myocardium (with arteriosclerosis), with, rheumatic fever (conditions in I00)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Insufficiency, insufficient, myocardial, myocardium (with arteriosclerosis), with, rheumatic fever (conditions in I00), inactive or quiescent (with chorea)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Myocarditis (with arteriosclerosis)(chronic)(fibroid) (interstitial) (old) (progressive) (senile), rheumatic (chronic) (inactive) (with chorea)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • and 4 more

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "I09.0 — Rheumatic myocarditis." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/i09.0-rheumatic-myocarditis

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Rheumatic myocarditis

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to I09.0 in its code family, with their registry titles.

View all codes in the I09 family