2026 ICD-10-CM Diagnosis Code C7B.8Other secondary neuroendocrine tumors

ICD-10-CM Codes›C00–D49›C7B›C7B

ICD-10-CM C7B.8
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C7B.8 is a billable ICD-10-CM diagnosis code for other secondary neuroendocrine tumors. 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. Coders also document this condition as carcinoma of peritoneum. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Malignant neuroendocrine tumors.

Code Identity

ICD-10-CM Code
C7B.8
Billable Status
Yes — Valid for Submission
Code Describes
Other secondary neuroendocrine tumors
Short Description
Other secondary neuroendocrine tumors
Same as the full description in the CMS dataset.
Parent Code
C7B
Secondary neuroendocrine tumors

Code Classification

ChapterC00–D49Neoplasms
SectionC7BSecondary neuroendocrine tumors
CategoryC7BSecondary neuroendocrine tumors
This CodeC7B.8Other secondary neuroendocrine tumors

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carcinoma of peritoneum
  • Secondary neuroendocrine carcinoma of peritoneum

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
      • neuroendocrine
        • secondary NEC
    • Tumor
      • secondary
        • neuroendocrine NEC

Clinical ClassificationClinical

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

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

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Convert C7B.8 to ICD-9-CMHistory

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

ICD-9-CM
209.79 Sec neuroend tu oth site
Approximate The match is approximate rather than exact.

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 C7B.8Overview

Is C7B.8 (Secondary neuroendocrine tumors) a billable code?

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

What MS-DRG does C7B.8 group to?

When other secondary neuroendocrine tumors 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 C7B.8?

Under the General Equivalence Mappings, other secondary neuroendocrine tumors converts to ICD-9-CM 209.79 (sec neuroend tu oth site). The mapping is approximate, so confirm the match fits the documentation.

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.