2026 ICD-10-CM Diagnosis Code C55Malignant neoplasm of uterus, part unspecified

ICD-10-CM Codes›C00–D49›C51-C58›C55

ICD-10-CM C55
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C55 is a billable ICD-10-CM diagnosis code for malignant neoplasm of uterus, part unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 736 through 741, 754 through 756. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Female reproductive system cancers - uterus.

Code Identity

ICD-10-CM Code
C55
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of uterus, part unspecified
Short Description
Malignant neoplasm of uterus, part unspecified
Same as the full description in the CMS dataset.
Chapter
C51-C58
Malignant neoplasms of female genital organs

Code Classification

ChapterC00–D49Neoplasms
SectionC51-C58Malignant neoplasms of female genital organs
CategoryC55Malignant neoplasm of uterus, part unspecified
This CodeC55Malignant neoplasm of uterus, part unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adenocarcinoma of uterus
  • Adenosarcoma of uterus
  • Carcinoma of uterus
  • Carcinosarcoma of uterus
  • Leiomyosarcoma of uterus
  • Malignant neoplasm involving left fallopian tube by direct extension from uterus
  • Malignant neoplasm involving right fallopian tube by direct extension from uterus
  • Malignant neoplasm involving urinary bladder by direct extension from uterus
  • Malignant neoplasm of uterus
  • Malignant tumor involving an organ by direct extension from uterus
  • Malignant tumor involving left ovary by direct extension from uterus
  • Malignant tumor involving rectum by direct extension from uterus
  • Malignant tumor involving right ovary by direct extension from uterus
  • Malignant tumor involving vagina by direct extension from uterus
  • Malignant tumor involving vulva by direct extension from uterus
  • Primary adenosarcoma of uterus
  • Primary carcinosarcoma of uterus
  • Primary malignant neoplasm of uterus
  • Primary myosarcoma of uterus
  • Sarcoma of uterus

Clinical ClassificationClinical

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

CCSR NEO031
Female reproductive system cancers - uterus
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

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

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
uterus, uteri, uterineC55C79.82D07.0D26.9D39.0D49.59

Patient EducationClinical

Uterine Cancer

Uterine cancer is a cancer that forms in tissues of the uterus, which is sometimes called the womb. The uterus is the place where a fetus grows during pregnancy.

The full article covers:

  • What is uterine cancer?
  • Who is more likely to develop uterine cancer?
  • What are the symptoms of uterine cancer?
  • How is uterine cancer diagnosed?
  • What are the treatments for uterine cancer?
  • Can uterine cancer be prevented?

Read the full article at MedlinePlus

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

Convert C55 to ICD-9-CMHistory

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

ICD-9-CM
179 Malig neopl uterus NOS
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 C55Overview

Is C55 (Malignant neoplasm of uterus, part unspecified) a billable code?

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

What MS-DRG does C55 group to?

When malignant neoplasm of uterus, part unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 736, 737, 738, 739, 740, 741, 754, 755, 756, with relative weights from 0.9605 to 3.5745 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C55?

Under the General Equivalence Mappings, malignant neoplasm of uterus, part unspecified converts to ICD-9-CM 179 (malig neopl uterus NOS). 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.