2026 ICD-10-CM Diagnosis Code C26.1Malignant neoplasm of spleen

ICD-10-CM Codes›C00–D49›C15-C26›C26

ICD-10-CM C26.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C26.1 is a billable ICD-10-CM diagnosis code for malignant neoplasm of spleen. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 820 through 825, 840 through 842. Coders also document this condition as angiosarcoma of spleen. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gastrointestinal cancers - all other types.

Code Identity

ICD-10-CM Code
C26.1
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of spleen
Short Description
Malignant neoplasm of spleen
Same as the full description in the CMS dataset.
Parent Code
C26
Malignant neoplasm of other and ill-defined digestive organs

Code Classification

ChapterC00–D49Neoplasms
SectionC15-C26Malignant neoplasms of digestive organs
CategoryC26Malignant neoplasm of other and ill-defined digestive organs
This CodeC26.1Malignant neoplasm of spleen

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Angiosarcoma of spleen
  • Fibrosarcoma
  • Fibrosarcoma of spleen
  • Malignant neoplasm of spleen
  • Primary fibrosarcoma of spleen
  • Primary malignant neoplasm of spleen

Tabular List NotesGuidance

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

Type 1 Excludes

  • Hodgkin lymphoma C81
  • non-Hodgkin lymphoma C82 C85

Clinical ClassificationClinical

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

CCSR NEO021
Gastrointestinal cancers - all other types
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Dermatofibrosarcoma

    a sarcoma of the deep layers of the skin. the tumors are locally aggressive tends to recur but rarely metastatic. it can be classified into variants depending on the cell type tumors are derived from or by its characteristics: pigmented variant from melanin-containing dermal dendritic cells; myxoid variant, myxoid stromal cells; giant cell variant characterized by giant cells in the tumors; and fibrosarcomatous variant chracterized by tumor areas histologically indistinguishable from fibrosarcoma.

  • Fibrosarcoma

    a sarcoma derived from deep fibrous tissue, characterized by bundles of immature proliferating fibroblasts with variable collagen formation, which tends to invade locally and metastasize by the bloodstream. (stedman, 25th ed)

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
spleen, splenic NECC26.1C78.89D01.7D13.99D37.8D49.0

Patient EducationClinical

Cancer

Cancer is not just one disease but many diseases. Cancer begins in your cells, which are the building blocks of your body. Usually, your body forms new cells as needed, replacing old cells that die. Sometimes this process goes wrong. New cells grow even when you don't need them, and old cells don't die when they should.

The full article covers:

  • What is cancer?
  • What are the types of cancer?
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Read the full article at MedlinePlus

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

Convert C26.1 to ICD-9-CMHistory

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

ICD-9-CM
159.1 Malignant neo spleen NEC
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 C26.1Overview

Is C26.1 (Malignant neoplasm of other and ill-defined digestive organs) a billable code?

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

What MS-DRG does C26.1 group to?

When malignant neoplasm of spleen is the principal diagnosis on an inpatient stay, it groups to MS-DRG 820, 821, 822, 823, 824, 825, 840, 841, 842, with relative weights from 1.0104 to 5.8648 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C26.1?

Under the General Equivalence Mappings, malignant neoplasm of spleen converts to ICD-9-CM 159.1 (malignant neo spleen NEC). 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.