2026 ICD-10-CM Diagnosis Code C44.501Unspecified malignant neoplasm of skin of breast
ICD-10-CM Codes›C00–D49›C43-C44›C44
- Billable — Valid for Submission
- Chronic Condition
C44.501 is a billable ICD-10-CM diagnosis code for unspecified malignant neoplasm of skin of breast. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. Coders also document this condition as cancer en cuirasse. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Skin cancers - all other types.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Cancer en cuirasse
- Carcinoma of skin of trunk
- Localized skin involvement by breast carcinoma
- Primary malignant neoplasm of skin of breast
- Primary malignant neoplasm of skin of left breast
- Primary malignant neoplasm of skin of right breast
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| breast (connective tissue) (glandular tissue) (soft parts) › mastectomy site (skin) [See Also: Neoplasm, breast, skin] | C44.501 | C79.2 | – | – | – | – |
| breast (connective tissue) (glandular tissue) (soft parts) › skin | C44.501 | C79.2 | D04.5 | D23.5 | D48.5 | D49.2 |
| mastectomy site (skin) [See Also: Neoplasm, breast, skin] | C44.501 | C79.2 | – | – | – | – |
| skin NOS › breast | C44.501 | C79.2 | D04.5 | D23.5 | D48.5 | D49.2 |
| skin NOS › mastectomy site (skin) [See Also: Neoplasm, skin, breast] | C44.501 | C79.2 | – | – | – | – |
Patient EducationClinical
Skin Cancer
Skin cancer is the most common form of cancer in the United States. The two most common types are basal cell cancer and squamous cell cancer. They usually form on the head, face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C44.501 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C44.501Overview
Is C44.501 (Unspecified malignant neoplasm of skin of trunk) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified malignant neoplasm of skin of breast on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C44.501 group to?
When unspecified malignant neoplasm of skin of breast is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of C44.501?
Under the General Equivalence Mappings, unspecified malignant neoplasm of skin of breast converts to ICD-9-CM 173.50 (malig neo skin trunk NOS). 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.
