E34.01 ICD-10-CM Code: Carcinoid heart syndrome

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for E34.01 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 E34.01 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for E34.01

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

Before you code E34.01

1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with E34.01. 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 E34.01’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.

   ReviewE20.1, N64.3, N62

Consider E34.01. Then review the Code Also 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).

Official instructions as workflow

• Excludes1 — check before selecting E34.01(3 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with E34.01: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareE20.1, N64.3, N62

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

• Code Also — related condition(3 notes)

  Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

  ReviewC7A, C7B

  See the official tabular notes · Guidelines I.A.17

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 (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.

• Carcinoidosis, heart
• Disease, diseased, carcinoid, heart
• Syndrome, carcinoid, heart
• Syndrome, Hedinger's

Don’t confuse E34.01 with…

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

The codes most likely to be picked instead of E34.01 — 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.

• E20.1— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of pseudohypoparathyroidism moves the case to E20.1; the two are not reported together unless documented as unrelated.

  Full comparison: E34.01 vs E20.1 →

• N64.3— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of galactorrhea moves the case to N64.3; the two are not reported together unless documented as unrelated.

  Full comparison: E34.01 vs N64.3 →

• N62— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of gynecomastia moves the case to N62; the two are not reported together unless documented as unrelated.

  Full comparison: E34.01 vs N62 →

• E34.00— 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 “Carcinoid syndrome, unspecified” takes E34.00; specificity in the record moves it back here.

  Full comparison: E34.01 vs E34.00 →

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

• 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 E34.01 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: G63 — Polyneuropathy in diseases classified elsewhere (via E34.-).

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 (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 11 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 3 MS-DRGs: DRG 643 (MDC 10), DRG 644 (MDC 10), DRG 645 (MDC 10).

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

Clinical classification (AHRQ CCSR):END015 — Other specified and unspecified endocrine 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.

E30.9 — Disorder of puberty, unspecified, E34.00 — Carcinoid syndrome, unspecified, E34.09 — Other carcinoid syndrome, E34.1 — Other hypersecretion of intestinal hormones, E34.2 — Ectopic hormone secretion, not elsewhere classified, E34.50 — Androgen insensitivity syndrome, unspecified, E34.51 — Complete androgen insensitivity syndrome, E34.52 — Partial androgen insensitivity syndrome, E34.8 — Other specified endocrine disorders, E34.9 — Endocrine disorder, unspecified

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic) for risk-adjusted payment.

C92.A1 — Acute myeloid leukemia with multilineage dysplasia, in remission, C92.A2 — Acute myeloid leukemia with multilineage dysplasia, in relapse, C93.00 — Acute monoblastic/monocytic leukemia, not having achieved remission, C93.01 — Acute monoblastic/monocytic leukemia, in remission, C93.02 — Acute monoblastic/monocytic leukemia, in relapse, C94.00 — Acute erythroid leukemia, not having achieved remission, C94.01 — Acute erythroid leukemia, in remission, C94.02 — Acute erythroid leukemia, in relapse, C94.20 — Acute megakaryoblastic leukemia not having achieved remission, C94.21 — Acute megakaryoblastic leukemia, in remission, C94.22 — Acute megakaryoblastic leukemia, in relapse, C94.40 — Acute panmyelosis with myelofibrosis not having achieved remission, C94.41 — Acute panmyelosis with myelofibrosis, in remission, C94.42 — Acute panmyelosis with myelofibrosis, in relapse, D46.22 — Refractory anemia with excess of blasts 2, E34.00 — Carcinoid syndrome, unspecified, E34.09 — Other carcinoid syndrome, I31.31 — Malignant pericardial effusion in diseases classified elsewhere, J91.0 — Malignant pleural effusion, R18.0 — Malignant ascites, +57 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.

Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers, Lung and Other Severe Cancers, Lymphoma and Other Cancers, Bladder, Colorectal, and Other Cancers, Prostate, Breast, and Other Cancers and Tumors

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Other specified and unspecified endocrine disorders).

E31.22 — Multiple endocrine neoplasia [MEN] type IIA, E31.23 — Multiple endocrine neoplasia [MEN] type IIB, E31.8 — Other polyglandular dysfunction, E31.9 — Polyglandular dysfunction, unspecified, E32.0 — Persistent hyperplasia of thymus, E32.1 — Abscess of thymus, E32.8 — Other diseases of thymus, E32.9 — Disease of thymus, unspecified, E34.0 — Carcinoid syndrome, E34.00 — Carcinoid syndrome, unspecified, E34.09 — Other carcinoid syndrome, E34.1 — Other hypersecretion of intestinal hormones, E34.2 — Ectopic hormone secretion, not elsewhere classified, E34.3 — Short stature due to endocrine disorder, E34.30 — Short stature due to endocrine disorder, unspecified, E34.31 — Constitutional short stature, E34.321 — Primary insulin-like growth factor-1 (IGF-1) deficiency, E34.322 — Insulin-like growth factor-1 (IGF-1) resistance, E34.328 — Other genetic causes of short stature, E34.329 — Unspecified genetic causes of short stature, +83 more

Contextual Map

Every relationship of E34.01 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 E34.01 with this related code in Claim Check

Hierarchy

• E00-E89 — Chapter 4: Endocrine, Nutritional and Metabolic Diseases (E00-E89) (E00-E89)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• E20-E35 — Disorders of other endocrine glands[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Code First instructions

• G63 — Polyneuropathy in diseases classified elsewhere[Code First](via E34.-): “endocrine disease, except diabetes (E00-E07, E15-E16, E20-E34)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• END015 — Other specified and unspecified endocrine disorders[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Risk adjustment (CMS-HCC)

• HCC 17 — Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic [CMS-HCC]: “Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic — supersedes HCC 18 (Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid), HCC 19 (Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers), HCC 20 (Lung and Other Severe Cancers), HCC 21 (Lymphoma and Other Cancers), HCC 22 (Bladder, Colorectal, and Other Cancers), HCC 23 (Prostate, Breast, and Other Cancers and Tumors)”— CMS-HCC V28 · 2026

MS-DRG Grouper

• CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• DRG 643 — ENDOCRINE DISORDERS WITH MCC[MS-DRG]: “ENDOCRINE DISORDERS WITH MCC (MDC 10)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 644 — ENDOCRINE DISORDERS WITH CC[MS-DRG]: “ENDOCRINE DISORDERS WITH CC (MDC 10)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 645 — ENDOCRINE DISORDERS WITHOUT CC/MCC[MS-DRG]: “ENDOCRINE DISORDERS WITHOUT CC/MCC (MDC 10)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 10 — Endocrine, Nutritional and Metabolic Diseases and Disorders[MDC crossing]: “Endocrine, Nutritional and Metabolic Diseases and Disorders — 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. 5,008 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Carcinoidosis, heart[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Disease, diseased, carcinoid, heart[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Syndrome, carcinoid, heart[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Syndrome, Hedinger's[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (22)

• E34 — Other endocrine disorders[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• E34.0 — Carcinoid syndrome[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• E34.00 — Carcinoid syndrome, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• E34.09 — Other carcinoid syndrome[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• E34.1 — Other hypersecretion of intestinal hormones[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• E34.2 — Ectopic hormone secretion, not elsewhere classified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• E34.3 — Short stature due to endocrine disorder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• E34.30 — Short stature due to endocrine disorder, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 14 more

Change history

• FY2025 — Added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2025

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 E34.01 in its code family, with their registry titles.

• E34 — Other endocrine disorders
• E34.0 — Carcinoid syndrome
• E34.00 — Carcinoid syndrome, unspecified
• E34.09 — Other carcinoid syndrome
• E34.1 — Other hypersecretion of intestinal hormones
• E34.2 — Ectopic hormone secretion, not elsewhere classified
• E34.3 — Short stature due to endocrine disorder
• E34.30 — Short stature due to endocrine disorder, unspecified
• E34.31 — Constitutional short stature
• E34.32 — Genetic causes of short stature

View all codes in the E34 family