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I44.2 ICD-10-CM Code: Atrioventricular block, complete

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

Coding at a Glance

Tabular directives
2 inclusion terms
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 96

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 308 — CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH MCC (MDC 05)
  • MS-DRG 309 — CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH CC (MDC 05)
  • MS-DRG 310 — CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITHOUT CC/MCC (MDC 05)
  • MS-DRG 791 — PREMATURITY WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)

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.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 238 — Specified Heart Arrhythmias

Other models: CMS-HCC V22 HCC 96

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I44.2 in the official ICD-10-CM tabular list, quoted as published.

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

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Complete heart block NOS
  • Third degree block

Code Overview

Atrioventricular block, complete is a billable ICD-10-CM diagnosis code (I44.2).

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 (16)

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

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 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):CIR016 — Conduction disorders (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 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.

I27.841 — Fontan-associated lymphatic dysfunction, I27.848 — Other Fontan-associated condition, I27.849 — Fontan related circulation, unspecified, I44.0 — Atrioventricular block, first degree, I44.1 — Atrioventricular block, second degree, I44.30 — Unspecified atrioventricular block, I44.39 — Other atrioventricular block, I44.4 — Left anterior fascicular block, I44.5 — Left posterior fascicular block, I44.60 — Unspecified fascicular block, I44.69 — Other fascicular block, I44.7 — Left bundle-branch block, unspecified, I45.0 — Right fascicular block, I45.10 — Unspecified right bundle-branch block, I45.19 — Other right bundle-branch block, I45.2 — Bifascicular block, I45.3 — Trifascicular block, I45.4 — Nonspecific intraventricular block, I45.5 — Other specified heart block, I45.6 — Pre-excitation syndrome, +30 more

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Specified Heart Arrhythmias) for risk-adjusted payment.

I47.0 — Re-entry ventricular arrhythmia, I47.20 — Ventricular tachycardia, unspecified, 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, I49.2 — Junctional premature depolarization, I49.5 — Sick sinus syndrome

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Conduction disorders).

I44.0 — Atrioventricular block, first degree, I44.1 — Atrioventricular block, second degree, I44.30 — Unspecified atrioventricular block, I44.39 — Other atrioventricular block, I44.4 — Left anterior fascicular block, I44.5 — Left posterior fascicular block, I44.60 — Unspecified fascicular block, I44.69 — Other fascicular block, I44.7 — Left bundle-branch block, unspecified, I45.0 — Right fascicular block, I45.10 — Unspecified right bundle-branch block, I45.19 — Other right bundle-branch block, I45.2 — Bifascicular block, I45.3 — Trifascicular block, I45.4 — Nonspecific intraventricular block, I45.5 — Other specified heart block, I45.6 — Pre-excitation syndrome, I45.81 — Long QT syndrome, I45.89 — Other specified conduction disorders, I45.9 — Conduction disorder, unspecified, +3 more

Same Index main term, other category

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

G47.2 — Circadian rhythm sleep disorders (sleep, inversion), G91.1 — Obstructive hydrocephalus (foramen Magendie), I45.0 — Right fascicular block (fascicular, right), I45.10 — Unspecified right bundle-branch block (bundle-branch, right), I45.19 — Other right bundle-branch block (bundle-branch, Wilson's type), I45.2 — Bifascicular block (bifascicular), I45.3 — Trifascicular block (trifascicular), I45.4 — Nonspecific intraventricular block (bundle-branch), I45.5 — Other specified heart block (nodal), I45.89 — Other specified conduction disorders (interference), I45.9 — Conduction disorder, unspecified (heart), I49.89 — Other specified cardiac arrhythmias not elsewhere classified (nodal), I49.9 — Cardiac arrhythmia, unspecified (escape), I81 — Portal vein thrombosis (portal), I82.0 — Budd-Chiari syndrome (hepatic vein), I82.90 — Acute embolism and thrombosis of unspecified vein (vein NOS), J84.10 — Pulmonary fibrosis, unspecified (alveolocapillary), N28.9 — Disorder of kidney and ureter, unspecified (kidney), N97.1 — Female infertility of tubal origin (tubal), N99.0 — Postprocedural (acute) (chronic) kidney failure (kidney, postcystoscopic or postprocedural), +2 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.

Iron Panel

Contextual Map

Every relationship of I44.2 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.

Hierarchy

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 238 — Specified Heart Arrhythmias [CMS-HCC]— CMS-HCC V28 · 2026

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
  • 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 (16)

  • Block, blocked, atrioventricular (incomplete) (partial), complete[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Block, blocked, atrioventricular (incomplete) (partial), third degree[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Block, blocked, atrioventricular (incomplete) (partial), with atrioventricular dissociation[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Block, blocked, conduction, complete[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Block, blocked, heart, complete (atrioventricular)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Block, blocked, heart, third degree (atrioventricular)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Block, blocked, third degree[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Disease, diseased, Lenegre's[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • and 8 more

Nearest codes (12)

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

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. "I44.2 — Atrioventricular block, complete." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/i44.2-atrioventricular-block-complete

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Atrioventricular block, complete

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 I44.2 in its code family, with their registry titles.

View all codes in the I44 family