2026 ICD-10-CM Diagnosis Code E34.00Carcinoid syndrome, unspecified

ICD-10-CM Codes›E00–E89›E20-E35›E34

ICD-10-CM E34.00
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E34.00 is a billable ICD-10-CM diagnosis code for carcinoid syndrome, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 643 through 645. Coders also document this condition as abnormality of serotonin secretion. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified endocrine disorders.

Code Identity

ICD-10-CM Code
E34.00
Billable Status
Yes — Valid for Submission
Code Describes
Carcinoid syndrome, unspecified
Short Description
Carcinoid syndrome, unspecified
Same as the full description in the CMS dataset.
Parent Code
E34.0
Carcinoid syndrome

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE20-E35Disorders of other endocrine glands
CategoryE34Other endocrine disorders
This CodeE34.00Carcinoid syndrome, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormality of serotonin secretion
  • Carcinoid crisis
  • Carcinoid syndrome
  • Serotonin level above reference range

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Carcinoid disease, unspecified

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Carcinoidosis
    • Disease, diseased
      • carcinoid
    • Syndrome
      • carcinoid
    • Syndrome
      • malignant
        • carcinoid
    • Syndrome
      • metastatic carcinoid

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END015
Other specified and unspecified endocrine disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement E34.00 replaces the following previously assigned code(s):

  • E34.0 - Carcinoid syndrome
FY 2025AddedAdded to the ICD-10-CM code setEffective October 1, 2024.
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E34.00Overview

Is E34.00 (Carcinoid syndrome) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report carcinoid syndrome, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E34.00 group to?

When carcinoid syndrome, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 643, 644, 645, with relative weights from 0.7683 to 1.6461 depending on complications. Higher weights mean higher Medicare reimbursement.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.