2026 ICD-10-CM Diagnosis Code D49.3Neoplasm of unspecified behavior of breast

ICD-10-CM CodesD50–D89D49D49

ICD-10-CM D49.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D49.3 is a billable ICD-10-CM diagnosis code for neoplasm of unspecified behavior of 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 Neoplasms of unspecified nature or uncertain behavior.

Code Identity

ICD-10-CM Code
D49.3
Billable Status
Yes — Valid for Submission
Code Describes
Neoplasm of unspecified behavior of breast
Short Description
Neoplasm of unspecified behavior of breast
Same as the full description in the CMS dataset.
Parent Code
Neoplasms of unspecified behavior

Code Classification

ChapterD50–D89Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
SectionD49Neoplasms of unspecified behavior
CategoryD49Neoplasms of unspecified behavior
This CodeD49.3Neoplasm of unspecified behavior of breast

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Neoplasm of areola
  • Neoplasm of axillary tail of breast
  • Neoplasm of breast
  • Neoplasm of central portion of breast
  • Neoplasm of ectopic site of breast
  • Neoplasm of lower inner quadrant of breast
  • Neoplasm of lower outer quadrant of breast
  • Neoplasm of nipple
  • Neoplasm of upper inner quadrant of breast
  • Neoplasm of upper outer quadrant of breast
  • Surgical margin involvement by tumor present

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • neoplasm of unspecified behavior of skin of breast D49.2

Clinical ClassificationClinical

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

CCSR NEO072
Neoplasms of unspecified nature or uncertain behavior
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.
areolaC50.0C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts)C50.9C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) areolaC50.0C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) axillary tailC50.6C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) central portionC50.1C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) innerC50.8C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) lowerC50.8C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) lower-inner quadrantC50.3C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) lower-outer quadrantC50.5C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) midlineC50.8C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) nippleC50.0C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) outerC50.8C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) tail (axillary)C50.6C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) upperC50.8C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) upper-inner quadrantC50.2C79.81D05.D24.D48.6D49.3
breast (connective tissue) (glandular tissue) (soft parts) upper-outer quadrantC50.4C79.81D05.D24.D48.6D49.3

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 D49.3 to ICD-9-CMHistory

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

ICD-9-CM
239.3 Breast neoplasm 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 D49.3Overview

Is D49.3 (Neoplasms of unspecified behavior) a billable code?

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

What MS-DRG does D49.3 group to?

When neoplasm of unspecified behavior of 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 D49.3?

Under the General Equivalence Mappings, neoplasm of unspecified behavior of breast converts to ICD-9-CM 239.3 (breast neoplasm NOS). The mapping is a direct match.

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.