2026 ICD-10-CM Diagnosis Code N64.59Other signs and symptoms in breast

ICD-10-CM Codes›N00–N99›N60-N65›N64

ICD-10-CM N64.59
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N64.59 is a billable ICD-10-CM diagnosis code for other signs and symptoms in breast. 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.

This medical diagnosis code is frequently used in OB/GYN medical specialties to designate conditions such lump in breast and other disorders of the breast.

Code Identity

ICD-10-CM Code
N64.59
Billable Status
Yes — Valid for Submission
Code Describes
Other signs and symptoms in breast
Short Description
Other signs and symptoms in breast
Same as the full description in the CMS dataset.
Parent Code
N64.5
Other signs and symptoms in breast

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN60-N65Disorders of breast
CategoryN64Other disorders of breast
This CodeN64.59Other signs and symptoms in breast

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Absent nipple
  • Areolas unequal in size
  • Bilateral changes in skin of breasts
  • Bilateral inversion of nipple
  • Bleeding from breast
  • Bleeding from nipple
  • Bleeding of surface of nipple
  • Breast asymmetry in adolescence
  • Breast changes
  • Breast cold
  • Breast depigmented
  • Breast disc palpable
  • Breast hot
  • Breast hypopigmented
  • Breast pigmented
  • Breast signs and symptoms
  • Breast symptom of change in nipple
  • Breast symptom of change in skin
  • Breast temperature - finding
  • Breasts asymmetrical
  • Chest swelling
  • Complex sclerosing lesion of breast
  • Complex sclerosing lesion of left breast
  • Complex sclerosing lesion of right breast
  • Contour of breast distorted
  • Deformation of breast
  • Destructive lesion of nipple
  • Dimpling of surface of breast
  • Discoloration of nipple
  • Discoloration of skin of breast
  • Displacement of nipple
  • Edema of breast
  • Edema of nipple
  • Engorgement of breasts
  • Finding of color of breast
  • Finding of color of nipple
  • Finding of consistency of breast
  • Finding of flow of breast milk
  • Finding of measures of lactation
  • Finding of proportion of nipple
  • Finding of quantity of lactation
  • Finding of sensation of nipple
  • Flat nipple
  • Hair sinus
  • Hair sinus of breast
  • Increase in surface veins of breast
  • Induration of breast
  • Induration of left breast
  • Induration of right breast
  • Inversion of left nipple
  • Inversion of nipple
  • Inversion of right nipple
  • Lactiferous duct palpable
  • Lactiferous duct prominent
  • Lactiferous ducts finding
  • Large areola
  • Large nipple
  • Lesion of left nipple
  • Lesion of nipple
  • Lesion of right nipple
  • Milk leaking from breast
  • Nipple bleeding
  • Nipple deformity
  • Nipple depigmented
  • Nipple hypopigmented
  • Nipples unequal in size
  • Position of nipple - finding
  • Red breast
  • Red nipple
  • Retraction of skin of breast
  • Rippling of surface of breast associated with prosthetic breast implant
  • Shape of breasts unequal
  • Sinus of breast
  • Size of breast - finding
  • Size of breasts unequal
  • Size of nipple - finding
  • Small breast
  • Small nipple
  • Soft breast
  • Sore nipple
  • Surface characteristics of breast - finding
  • Swelling of breast
  • Swelling of nipple
  • Symmetry of breasts - finding
  • Thickening of skin
  • Thickening of skin of breast
  • Veins visible on breast
  • Wide spaced nipples

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.

    • Bleeding
      • nipple
    • Congestion, congestive
      • breast
    • Engorgement
      • breast
    • Hemorrhage, hemorrhagic(concealed)
      • breast
    • Hemorrhage, hemorrhagic(concealed)
      • nipple
    • Inversion
      • nipple
    • Symptoms NEC
      • breast NEC
    • Thickening
      • breast

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.

Convert N64.59 to ICD-9-CMHistory

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

ICD-9-CM
611.79 Symptoms in breast NEC
Approximate The match is approximate rather than exact.

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 N64.59Overview

Is N64.59 (Other signs and symptoms in breast) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other signs and symptoms in breast on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N64.59 group to?

When other signs and symptoms in breast 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.

What is the ICD-9 equivalent of N64.59?

Under the General Equivalence Mappings, other signs and symptoms in breast converts to ICD-9-CM 611.79 (symptoms in breast NEC). The mapping is approximate, so confirm the match fits the documentation.

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.