2026 ICD-10-CM Diagnosis Code N63.25Unspecified lump in the left breast, overlapping quadrants

ICD-10-CM Codes›N00–N99›N60-N65›N63

ICD-10-CM N63.25
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N63.25 is a billable ICD-10-CM diagnosis code for unspecified lump in the left breast, overlapping quadrants. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 600 through 601. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nonmalignant breast conditions.

Code Identity

ICD-10-CM Code
N63.25
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified lump in the left breast, overlapping quadrants
Short Description
Unspecified lump in the left breast, overlapping quadrants
Same as the full description in the CMS dataset.
Parent Code
N63.2
Unspecified lump in the left breast

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN60-N65Disorders of breast
CategoryN63Unspecified lump in breast
This CodeN63.25Unspecified lump in the left breast, overlapping quadrants

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.

    • Lump
      • breast
        • left
          • overlapping quadrants

Clinical ClassificationClinical

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

CCSR GEN017
Nonmalignant breast conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Breast Diseases

Breast diseases include various conditions and changes in your breast. Most women experience breast changes at some time. Your age, hormone levels, and medicines you take may cause lumps, bumps, and discharges of fluids that are not breast milk.

The full article covers:

  • What are breast diseases?
  • What are the symptoms of breast disease?
  • How are breast diseases diagnosed?
  • What are the treatments for breast disease?

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement N63.25 replaces the following previously assigned code(s):

  • N63.21 - Unspecified lump in the left breast, upper outer quadrant
  • N63.22 - Unspecified lump in the left breast, upper inner quadrant
  • N63.23 - Unspecified lump in the left breast, lower outer quadrant
  • N63.24 - Unspecified lump in the left breast, lower inner quadrant
FY 2020AddedAdded to the ICD-10-CM code setEffective October 1, 2019.
FY 2021–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About N63.25Overview

Is N63.25 (Unspecified lump in the left breast) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified lump in the left breast, overlapping quadrants on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N63.25 group to?

When unspecified lump in the left breast, overlapping quadrants is the principal diagnosis on an inpatient stay, it groups to MS-DRG 600, 601, with relative weights from 0.6050 to 1.0416 depending on complications. Higher weights mean higher Medicare reimbursement.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.