I49.02 ICD-10-CM Code: Ventricular flutter

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I49.02 in the official ICD-10-CM tabular list, quoted as published.

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

Notes without a marker are published on I49.02 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for I49.02

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

Choose the right path

1. Is the underlying (etiologic) condition the Code First note names documented?
   Yes → Sequence the underlying condition first, then I49.02.
   No → Continue; do not add an underlying condition the record does not document.

   ReviewO08.8, O75.4

Consider I49.02. 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).

The underlying (etiologic) condition

Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).

Official instructions as workflow

• Excludes2 — not part of I49.02(5 notes)

  Coding workflow: The conditions named in this note are not included in I49.02. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareR00.1, P29.1

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

• Code First — sequencing check(3 notes)

  Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before I49.02. Do not add an underlying condition the record does not document.

  ReviewO08.8, O75.4

  See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

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

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.

Indexed Clinical Terms (2)

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.

• Flutter, heart, ventricular
• Flutter, ventricular

Don’t confuse I49.02 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of I49.02 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• R00.1— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of bradycardia NOS adds R00.1; it is not part of this code and both may be reported when both are documented.

  Full comparison: I49.02 vs R00.1 →

• P29.1— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of neonatal dysrhythmia adds P29.1; it is not part of this code and both may be reported when both are documented.

  Full comparison: I49.02 vs P29.1 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• MCC 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 I49.02 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 Excludes2 note: R00 — Abnormalities of heart beat (via I49.-).

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

Referenced by 1 Code Also instruction: M35.81 — Multisystem inflammatory syndrome (via I49.-).

These codes suggest coding this condition alongside when both are present.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: MCC — Major 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 51 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 5 MS-DRGs: DRG 308 (MDC 05), DRG 309 (MDC 05), DRG 310 (MDC 05), DRG 791 (MDC 15), DRG 793 (MDC 15).

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

Clinical classification (AHRQ CCSR):CIR018 — Cardiac arrest and ventricular fibrillation (default).

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 MCC — 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.

I47.21 — Torsades de pointes, I47.29 — Other ventricular tachycardia, I47.9 — Paroxysmal tachycardia, unspecified, I48.0 — Paroxysmal atrial fibrillation, I48.11 — Longstanding persistent atrial fibrillation, I48.19 — Other persistent atrial fibrillation, I48.20 — Chronic atrial fibrillation, unspecified, I48.21 — Permanent atrial fibrillation, I48.3 — Typical atrial flutter, I48.4 — Atypical atrial flutter, I48.91 — Unspecified atrial fibrillation, I48.92 — Unspecified atrial flutter, I49.01 — Ventricular fibrillation, I49.2 — Junctional premature depolarization, I49.8 — Other specified cardiac arrhythmias, I87.8 — Other specified disorders of veins, I87.9 — Disorder of vein, unspecified, I99.8 — Other disorder of circulatory system, I99.9 — Unspecified disorder of circulatory system, R00.1 — Bradycardia, unspecified, +30 more

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Cardio-Respiratory Failure and Shock) for risk-adjusted payment.

I46.2 — Cardiac arrest due to underlying cardiac condition, I46.8 — Cardiac arrest due to other underlying condition, I46.9 — Cardiac arrest, cause unspecified, I49.01 — Ventricular fibrillation, J80 — Acute respiratory distress syndrome, J81.0 — Acute pulmonary edema, J96.00 — Acute respiratory failure, unspecified whether with hypoxia or hypercapnia, J96.01 — Acute respiratory failure with hypoxia, J96.02 — Acute respiratory failure with hypercapnia, J96.10 — Chronic respiratory failure, unspecified whether with hypoxia or hypercapnia, J96.11 — Chronic respiratory failure with hypoxia, J96.12 — Chronic respiratory failure with hypercapnia, J96.20 — Acute and chronic respiratory failure, unspecified whether with hypoxia or hypercapnia, J96.21 — Acute and chronic respiratory failure with hypoxia, J96.22 — Acute and chronic respiratory failure with hypercapnia, J96.90 — Respiratory failure, unspecified, unspecified whether with hypoxia or hypercapnia, J96.91 — Respiratory failure, unspecified with hypoxia, J96.92 — Respiratory failure, unspecified with hypercapnia, P22.0 — Respiratory distress syndrome of newborn, P26.0 — Tracheobronchial hemorrhage originating in the perinatal period, +15 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Respirator Dependence/Tracheostomy Status/Complications, Respiratory Arrest

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Cardiac arrest and ventricular fibrillation).

I46.2 — Cardiac arrest due to underlying cardiac condition, I46.8 — Cardiac arrest due to other underlying condition, I46.9 — Cardiac arrest, cause unspecified, I49.01 — Ventricular fibrillation, I97.120 — Postprocedural cardiac arrest following cardiac surgery, I97.121 — Postprocedural cardiac arrest following other surgery, I97.710 — Intraoperative cardiac arrest during cardiac surgery, I97.711 — Intraoperative cardiac arrest during other surgery, O03.36 — Cardiac arrest following incomplete spontaneous abortion, O03.86 — Cardiac arrest following complete or unspecified spontaneous abortion, O04.86 — Cardiac arrest following (induced) termination of pregnancy, O07.36 — Cardiac arrest following failed attempted termination of pregnancy, O08.81 — Cardiac arrest following an ectopic and molar pregnancy, O29.111 — Cardiac arrest due to anesthesia during pregnancy, first trimester, O29.112 — Cardiac arrest due to anesthesia during pregnancy, second trimester, O29.113 — Cardiac arrest due to anesthesia during pregnancy, third trimester, O29.119 — Cardiac arrest due to anesthesia during pregnancy, unspecified trimester

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Flutter”; these codes share that main term but sit in a different category of the Tabular List.

I48.3 — Typical atrial flutter (atrial or auricular, type I), I48.4 — Atypical atrial flutter (atrial or auricular, type II), I48.92 — Unspecified atrial flutter (atrial or auricular)

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.

Iron Panel, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of I49.02 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 I49.02 with these 2 related codes in Claim Check

Hierarchy

• I00-I99 — Chapter 9: Diseases of the Circulatory System (I00-I99) (I00-I99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I30-I5A — Other forms of heart disease[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes2 notes

• R00 — Abnormalities of heart beat[Excludes2](via I49.-): “specified arrhythmias (I47-I49)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code Also instructions

• M35.81 — Multisystem inflammatory syndrome[Code Also](via I49.-): “cardiac arrhythmia (I47-I49.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• CIR018 — Cardiac arrest and ventricular fibrillation[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Risk adjustment (CMS-HCC)

• HCC 213 — Cardio-Respiratory Failure and Shock [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

• MCC — Major Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (MCC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• DRG 308 — CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH MCC[MS-DRG]: “CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH MCC (MDC 05)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 309 — CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH CC[MS-DRG]: “CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH CC (MDC 05)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 310 — CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITHOUT CC/MCC[MS-DRG]: “CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITHOUT CC/MCC (MDC 05)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 791 — PREMATURITY WITH MAJOR PROBLEMS[MS-DRG]: “PREMATURITY WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS[MS-DRG]: “FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

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
• MDC 15 — Newborns and Other Neonates with Conditions Originating in Perinatal Period[MDC crossing]: “Newborns and Other Neonates with Conditions Originating in Perinatal Period — 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.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Flutter, heart, ventricular[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Flutter, ventricular[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (15)

• I49 — Other cardiac arrhythmias[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I49.0 — Ventricular fibrillation and flutter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I49.01 — Ventricular fibrillation[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I49.1 — Atrial premature depolarization[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I49.2 — Junctional premature depolarization[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I49.3 — Ventricular premature depolarization[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I49.4 — Other and unspecified premature depolarization[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I49.40 — Unspecified premature depolarization[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 7 more

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

Risk adjustment Official source data

2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release 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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to I49.02 in its code family, with their registry titles.

• I49 — Other cardiac arrhythmias
• I49.0 — Ventricular fibrillation and flutter
• I49.01 — Ventricular fibrillation
• I49.1 — Atrial premature depolarization
• I49.2 — Junctional premature depolarization
• I49.3 — Ventricular premature depolarization
• I49.4 — Other and unspecified premature depolarization
• I49.40 — Unspecified premature depolarization
• I49.49 — Other premature depolarization
• I49.5 — Sick sinus syndrome

View all codes in the I49 family