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I42.7 ICD-10-CM Code: Cardiomyopathy due to drug and external agent

Compare with another code for I42.7Check this code on a claim

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

Coding at a Glance

Tabular directives
1 inclusion term · 3 Excludes2 · 1 use-additional code · 2 code-first instructions
Risk adjustment
CMS-HCC V22 category 85 · RxHCC V08 category 186

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, and is marked with where it comes from.

Code firstSequence the underlying condition before this code
  • poisoning due to drug or toxin, if applicable (T36-T65 with fifth or sixth character 1-4)
  • pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4) (from I42)
Use additional codeReport with this code when documented
  • Use additional code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)
Excludes2from I42Not included here; may be reported together
  • ischemic cardiomyopathy (I25.5)
  • peripartum cardiomyopathy (O90.3)
  • ventricular hypertrophy (I51.7)
Includesfrom I42What I42 covers
  • myocardiopathy

Where it sits Source: CMS/NCHS

Under:Chapter 9: Diseases of the Circulatory SystemI30-I5A Other forms of heart diseaseI42 Cardiomyopathy

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

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 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 I42.7 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

Notes without a marker are published on I42.7 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • myocardiopathy

Source: inherited from I42

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from I42

Code First

Underlying conditions that must be sequenced before this code.

  • poisoning due to drug or toxin, if applicable (T36-T65 with fifth or sixth character 1-4)
  • pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4) inherited from I42

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Coder workflow for I42.7

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

Before you code I42.7

  1. I42.7’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

    Guide: Combination codes →

Choose the right path

  1. Is the underlying (etiologic) condition the Code First note names documented?
    Yes → Sequence the underlying condition first, then I42.7.
    No → Continue; do not add an underlying condition the record does not document.

    ReviewO99.4

Consider I42.7. Then work the Use Additional Code note, and 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 associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
The underlying (etiologic) condition
Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes2 — not part of I42.7(3 notes)

    Coding workflow: The conditions named in this note are not included in I42.7. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareI25.5, O90.3, I51.7

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

  • Code First — sequencing check(2 notes)

    Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before I42.7. Do not add an underlying condition the record does not document.

    ReviewO99.4

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

  • Use Additional Code — after identifying I42.7(1 note)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with I42.7 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

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

Coding decision scenarios

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

Documentation: Only one of the components this code’s title joins is documented.

Coding question: Is I42.7 supported?

Path: Review the code for the documented component on its own.

Reason: A combination code is assigned only when it fully identifies the documented conditions; otherwise the documented component takes its own code (Guidelines I.B.9).

Documentation: The underlying condition the Code First note names is documented alongside this condition.

Coding question: How are the two sequenced?

Path: Review the Code First note.

Reason: The underlying condition is sequenced first and the manifestation follows (Guidelines I.A.13).

ReviewO99.4

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with I42.7?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

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.

Don’t confuse I42.7 with…

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

The codes most likely to be picked instead of I42.7 — 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.

  • I42.9— 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 “Cardiomyopathy, unspecified” takes I42.9; specificity in the record moves it back here.

    Full comparison: I42.7 vs I42.9 →

  • I25.5— 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 ischemic cardiomyopathy adds I25.5; it is not part of this code and both may be reported when both are documented.

    Full comparison: I42.7 vs I25.5 →

  • O90.3— 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 peripartum cardiomyopathy adds O90.3; it is not part of this code and both may be reported when both are documented.

    Full comparison: I42.7 vs O90.3 →

  • I51.7— 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 ventricular hypertrophy adds I51.7; it is not part of this code and both may be reported when both are documented.

    Full comparison: I42.7 vs I51.7 →

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

Cardiomyopathy due to drug and external agent is a billable ICD-10-CM diagnosis code (I42.7).

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

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. Sequencing: 2 Code First instructions — the underlying condition is sequenced before this code when present. See the Code First notes
  2. 1 Use Additional Code instruction — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
  3. 3 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

  • CC as a secondary diagnosis (FY2027). 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-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name I42.7 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 Code First instruction: I5A — Non-ischemic myocardial injury (non-traumatic) (via I42.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 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 117 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):INJ030 — Drug induced or toxic related condition (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.

I27.849 — Fontan related circulation, unspecified, I42.00 — Dilated cardiomyopathy, unspecified, I42.01 — Familial-genetic dilated cardiomyopathy, I42.09 — Other dilated cardiomyopathy, I42.1 — Obstructive hypertrophic cardiomyopathy, I42.2 — Other hypertrophic cardiomyopathy, I42.3 — Endomyocardial (eosinophilic) disease, I42.4 — Endocardial fibroelastosis, I42.5 — Other restrictive cardiomyopathy, I42.6 — Alcoholic cardiomyopathy, I42.81 — Arrhythmogenic cardiomyopathy, I42.89 — Other cardiomyopathies not elsewhere classified, I42.9 — Cardiomyopathy, unspecified, I44.0 — Atrioventricular block, first degree, I44.1 — Atrioventricular block, second degree, I44.30 — Unspecified atrioventricular block, I44.39 — Other atrioventricular block, I45.2 — Bifascicular block, I45.3 — Trifascicular block, I45.4 — Nonspecific intraventricular block, +96 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Drug induced or toxic related condition, Myocarditis and cardiomyopathy).

I40.8 — Other acute myocarditis, I40.9 — Acute myocarditis, unspecified, I41 — Myocarditis in diseases classified elsewhere, I42.0 — Dilated cardiomyopathy, I42.1 — Obstructive hypertrophic cardiomyopathy, I42.2 — Other hypertrophic cardiomyopathy, I42.3 — Endomyocardial (eosinophilic) disease, I42.4 — Endocardial fibroelastosis, I42.5 — Other restrictive cardiomyopathy, I42.6 — Alcoholic cardiomyopathy, I42.8 — Other cardiomyopathies, I42.9 — Cardiomyopathy, unspecified, I43 — Cardiomyopathy in diseases classified elsewhere, I51.4 — Myocarditis, unspecified, I95.2 — Hypotension due to drugs, J10.82 — Influenza due to other identified influenza virus with myocarditis, J11.82 — Influenza due to unidentified influenza virus with myocarditis, J70.2 — Acute drug-induced interstitial lung disorders, J70.3 — Chronic drug-induced interstitial lung disorders, J70.4 — Drug-induced interstitial lung disorders, unspecified, +259 more

Same Index main term, other category

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

A18.84 — Tuberculosis of heart (tuberculous), B33.24 — Viral cardiomyopathy (viral), B57.0 — Acute Chagas' disease with heart involvement (in, Chagas' disease, acute), B57.2 — Chagas' disease (chronic) with heart involvement (in, Chagas' disease), D86.85 — Sarcoid myocarditis (in, sarcoidosis), E05.90 — Thyrotoxicosis, unspecified without thyrotoxic crisis or storm (thyrotoxic), E05.91 — Thyrotoxicosis, unspecified with thyrotoxic crisis or storm (thyrotoxic, with storm), E51.12 — Wet beriberi (beriberi), E63.9 — Nutritional deficiency, unspecified (nutritional), E74.02 — Pompe disease (glycogen storage), E85.4 — Organ-limited amyloidosis (amyloid), E88.9 — Metabolic disorder, unspecified (metabolic), G11.11 — Friedreich ataxia (in, Friedreich's ataxia), G71.09 — Other specified muscular dystrophies (in, progressive muscular dystrophy), G71.11 — Myotonic muscular dystrophy (in, myotonia atrophica), I09.0 — Rheumatic myocarditis (rheumatic), I25.5 — Ischemic cardiomyopathy (ischemic), I51.81 — Takotsubo syndrome (takotsubo), O90.3 — Peripartum cardiomyopathy (peripartum), Q24.8 — Other specified congenital malformations of heart (hypertrophic, obstructive, congenital)

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.

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

Contextual Map

Every relationship of I42.7 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 I42.7 with these 9 related codes in Claim Check

Hierarchy

Code First (30)

Use Additional Code (15)

Referenced by Code First instructions

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

Index entries

  • Cardiomyopathy (familial) (idiopathic), due to, drugs[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Cardiomyopathy (familial) (idiopathic), due to, external agents NEC[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Cardiomyopathy (familial) (idiopathic), toxic NEC[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic), toxic NEC[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (15)

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 (4)

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 28, 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. "I42.7 — Cardiomyopathy due to drug and external agent." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/i42.7-cardiomyopathy-due-to-drug-and-external-agent

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Cardiomyopathy due to drug and external agent

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 I42.7 in its code family, with their registry titles.

View all codes in the I42 family