2026 ICD-10-CM Diagnosis Code N61.20Granulomatous mastitis, unspecified breast

ICD-10-CM Codes›N00–N99›N60-N65›N61

ICD-10-CM N61.20
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N61.20 is a billable ICD-10-CM diagnosis code for granulomatous mastitis, unspecified 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. Coders also document this condition as granulomatous mastitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nonmalignant breast conditions.

Code Identity

ICD-10-CM Code
N61.20
Billable Status
Yes — Valid for Submission
Code Describes
Granulomatous mastitis, unspecified breast
Short Description
Granulomatous mastitis, unspecified breast
Same as the full description in the CMS dataset.
Parent Code
N61.2
Granulomatous mastitis

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN60-N65Disorders of breast
CategoryN61Inflammatory disorders of breast
This CodeN61.20Granulomatous mastitis, unspecified breast

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Granulomatous mastitis

Clinical ClassificationClinical

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

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

Clinical InformationClinical

  • Granulomatous Mastitis

    a rare, benign, inflammatory breast disease occurring in premenopausal women shortly after a recent pregnancy. the origin is unknown but it is commonly mistaken for malignancy and sometimes associated with breast feeding and the use of oral contraceptives.

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 N61.20 replaces the following previously assigned code(s):

  • N61.0 - Mastitis without abscess
FY 2021AddedAdded to the ICD-10-CM code setEffective October 1, 2020.
FY 2022–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About N61.20Overview

Is N61.20 (Granulomatous mastitis) a billable code?

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

What MS-DRG does N61.20 group to?

When granulomatous mastitis, unspecified 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.

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.