2026 ICD-10-CM Diagnosis Code C7A.00Malignant carcinoid tumor of unspecified site

ICD-10-CM Codes›C00–D49›C7A›C7A

ICD-10-CM C7A.00
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C7A.00 is a billable ICD-10-CM diagnosis code for malignant carcinoid tumor of unspecified site. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 826 through 830, 843 through 845. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Malignant neuroendocrine tumors.

Code Identity

ICD-10-CM Code
C7A.00
Billable Status
Yes — Valid for Submission
Code Describes
Malignant carcinoid tumor of unspecified site
Short Description
Malignant carcinoid tumor of unspecified site
Same as the full description in the CMS dataset.
Parent Code
C7A.0
Malignant carcinoid tumors

Code Classification

ChapterC00–D49Neoplasms
SectionC7AMalignant neuroendocrine tumors
CategoryC7AMalignant neuroendocrine tumors
This CodeC7A.00Malignant carcinoid tumor of unspecified site

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Enterochromaffin cell tumor
  • Malignant carcinoid tumor of left lung
  • Malignant carcinoid tumor of right lung
  • Metastatic well-differentiated neuroendocrine tumor
  • Metastatic well-differentiated neuroendocrine tumor to left lung
  • Metastatic well-differentiated neuroendocrine tumor to lung
  • Metastatic well-differentiated neuroendocrine tumor to regional lymph node
  • Metastatic well-differentiated neuroendocrine tumor to right lung
  • Poorly differentiated malignant carcinoid tumor
  • Tricuspid valve regurgitation due to neuroendocrine tumor
  • Tricuspid valve stenosis due to neuroendocrine tumor
  • Tricuspid valve stenosis with insufficiency
  • Tricuspid valve stenosis with regurgitation due to neuroendocrine tumor
  • Well-differentiated neuroendocrine tumor
  • Well-differentiated neuroendocrine tumor of gastrointestinal tract
  • Well-differentiated neuroendocrine tumor of intestine

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.

    • Tumor
      • carcinoid
        • malignant

Clinical ClassificationClinical

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

CCSR NEO066
Malignant neuroendocrine tumors
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Carcinoid Tumors

Carcinoid tumors are rare, slow-growing cancers. They usually start in the lining of the digestive tract or in the lungs. They grow slowly and don't produce symptoms in the early stages. As a result, the average age of people diagnosed with digestive or lung carcinoids is about 60.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert C7A.00 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
209.20 Mal crcnd prim site unkn
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C7A.00Overview

Is C7A.00 (Malignant carcinoid tumors) a billable code?

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

What MS-DRG does C7A.00 group to?

When malignant carcinoid tumor of unspecified site is the principal diagnosis on an inpatient stay, it groups to MS-DRG 826, 827, 828, 829, 830, 843, 844, 845, with relative weights from 0.8516 to 4.6778 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C7A.00?

Under the General Equivalence Mappings, malignant carcinoid tumor of unspecified site converts to ICD-9-CM 209.20 (mal crcnd prim site unkn). The mapping is a direct match.

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.