2026 ICD-10-CM Diagnosis Code C50.A1Malignant inflammatory neoplasm of right breast

ICD-10-CM Codes›C00–D49›C50›C50

ICD-10-CM C50.A1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C50.A1 is a billable ICD-10-CM diagnosis code for malignant inflammatory neoplasm of right breast. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 582 through 583, 597 through 599.

Code Identity

ICD-10-CM Code
C50.A1
Billable Status
Yes — Valid for Submission
Code Describes
Malignant inflammatory neoplasm of right breast
Short Description
Malignant inflammatory neoplasm of right breast
Same as the full description in the CMS dataset.
Parent Code
C50.A
Malignant inflammatory neoplasm of breast

Code Classification

ChapterC00–D49Neoplasms
SectionC50Malignant neoplasms of breast
CategoryC50Malignant neoplasm of breast
This CodeC50.A1Malignant inflammatory neoplasm of right breast

Table of NeoplasmsClinical

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

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
breast (connective tissue) (glandular tissue) (soft parts) › inflammatoryC50.A–––––

Code History & ChangesHistory

New Code C50.A1 was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement C50.A1 replaces the following previously assigned code(s):

  • C50.911 - Malignant neoplasm of unsp site of right female breast
  • C50.921 - Malignant neoplasm of unspecified site of right male breast
FY 2026AddedAdded to the ICD-10-CM code setEffective October 1, 2025.
FY 2026CurrentRevised in the current code setEffective October 1, 2025 through September 30, 2026.

Questions About C50.A1Overview

Is C50.A1 (Malignant inflammatory neoplasm of breast) a billable code?

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

What MS-DRG does C50.A1 group to?

When malignant inflammatory neoplasm of right breast is the principal diagnosis on an inpatient stay, it groups to MS-DRG 582, 583, 597, 598, 599, with relative weights from 0.7332 to 1.9266 depending on complications. Higher weights mean higher Medicare reimbursement.