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I45.6 ICD-10-CM Code: Pre-excitation syndrome

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

Coding at a Glance

Tabular directives
6 inclusion terms

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

IncludesWhat this code covers
  • Accelerated atrioventricular conduction
  • Accessory atrioventricular conduction
  • Anomalous atrioventricular excitation
  • Lown-Ganong-Levine syndrome

+2 more in Instructions

CompareCheck ClaimView Related Codes

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 v44, 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.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I45.6 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Accelerated atrioventricular conduction
  • Accessory atrioventricular conduction
  • Anomalous atrioventricular excitation
  • Lown-Ganong-Levine syndrome
  • Pre-excitation atrioventricular conduction
  • Wolff-Parkinson-White syndrome

Don’t confuse I45.6 with…

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

The codes most likely to be picked instead of I45.6 — 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.

  • I45.1— Specificity relationship (Review)

    Overlapping diagnoses in the same category.

    Overlapping codes in the same category — the documentation decides which is the more specific fit.

    What moves you there: A record that documents no more than “Other and unspecified right bundle-branch block” takes I45.1; specificity in the record moves it back here.

    Full comparison: I45.6 vs I45.1 →

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.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Pre-excitation syndrome is a billable ICD-10-CM diagnosis code (I45.6).

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

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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-derived relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

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 category (CCSR)

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

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, I45.81 — Long QT syndrome, I45.89 — Other specified conduction disorders, I45.9 — Conduction disorder, unspecified, Z45.010 — Encounter for checking and testing of cardiac pacemaker pulse generator [battery], Z45.018 — Encounter for adjustment and management of other part of cardiac pacemaker, Z95.0 — Presence of cardiac pacemaker, +3 more

Same Index main term, other category

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

E70.330 — Chediak-Higashi syndrome (Chédiak-Higashi), F30.8 — Other manic episodes (reactive), H57.00 — Unspecified anomaly of pupillary function (pupil, function), H57.01 — Argyll Robertson pupil, atypical (pupil, function, Argyll Robertson pupil), H57.02 — Anisocoria (pupil, function, anisocoria), H57.03 — Miosis (pupil, function, miosis), H57.04 — Mydriasis (pupil, function, mydriasis), H57.05 — Tonic pupil (pupil, function, tonic pupil), H57.09 — Other anomalies of pupillary function (pupil, function, specified type NEC), I42.4 — Endocardial fibroelastosis (heart, fibroelastosis cordis), K00.1 — Supernumerary teeth (teeth, tooth), K00.2 — Abnormalities of size and form of teeth (roots), K00.6 — Disturbances in tooth eruption (tooth, teeth, eruption), K00.9 — Disorder of tooth development, unspecified (tooth, teeth), K04.3 — Abnormal hard tissue formation in pulp (hard tissue formation in pulp), L81.9 — Disorder of pigmentation, unspecified (pigmentation), M26.00 — Unspecified anomaly of jaw size (dentofacial, jaw size), M26.01 — Maxillary hyperplasia (dentofacial, jaw size, maxillary, hyperplasia), M26.02 — Maxillary hypoplasia (dentofacial, jaw size, maxillary, hypoplasia), M26.03 — Mandibular hyperplasia (dentofacial, jaw size, mandibular, hyperplasia), +260 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 I45.6 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)

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. 15,708 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027
  • 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 · FY2027

Index entries

  • Accelerated atrioventricular conduction[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Accessory (congenital), atrioventricular conduction[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Anomaly, anomalous (congenital) (unspecified type), atrioventricular, excitation[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Excitation, anomalous atrioventricular[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Lown-Ganong-Levine syndrome[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Pre-excitation atrioventricular conduction[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Wolff-Parkinson-White syndrome[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (13)

Change history

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

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Indexed Clinical Terms (7)

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.

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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 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 — v44 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-derived 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 editorial 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.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

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. "I45.6 — Pre-excitation syndrome." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/i45.6-pre-excitation-syndrome

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Pre-excitation syndrome

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, 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 I45.6 in its code family, with their registry titles.

View all codes in the I45 family