2026 ICD-10-CM Diagnosis Code N60.12Diffuse cystic mastopathy of left breast

ICD-10-CM Codes›N00–N99›N60-N65›N60

ICD-10-CM N60.12
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N60.12 is a billable ICD-10-CM diagnosis code for diffuse cystic mastopathy of left 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. The code is restricted by the Medicare Code Editor to adult patients (age 15 through 124). Coders also document this condition as fibrocystic change of left breast. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nonmalignant breast conditions.

Code Identity

ICD-10-CM Code
N60.12
Billable Status
Yes — Valid for Submission
Code Describes
Diffuse cystic mastopathy of left breast
Short Description
Diffuse cystic mastopathy of left breast
Same as the full description in the CMS dataset.
Parent Code
N60.1
Diffuse cystic mastopathy

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN60-N65Disorders of breast
CategoryN60Benign mammary dysplasia
This CodeN60.12Diffuse cystic mastopathy of left breast

Code EditsBilling

Medicare Code Editor checks that affect claim validity for N60.12.

Adult diagnoses
The Medicare Code Editor detects inconsistencies in adult cases by checking a patient's age and any diagnosis on the patient's record. The adult code edits apply to patients age range is 15–124 years inclusive (e.g., senile delirium, mature cataract).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Fibrocystic change of left breast
  • Fibrocystic change of right breast
  • Fibrocystic changes of bilateral breasts
  • Fibrocystic disease of 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 N60.12 to ICD-9-CMHistory

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

ICD-9-CM
610.1 Diffus cystic mastopathy
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 N60.12Overview

Is N60.12 (Diffuse cystic mastopathy) a billable code?

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

What MS-DRG does N60.12 group to?

When diffuse cystic mastopathy of left 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.

Who can N60.12 be reported for?

The Medicare Code Editor checks diffuse cystic mastopathy of left breast against patient demographics: this code is intended for adult patients (age 15 through 124). Claims outside these limits are flagged as inconsistent.

What is the ICD-9 equivalent of N60.12?

Under the General Equivalence Mappings, diffuse cystic mastopathy of left breast converts to ICD-9-CM 610.1 (diffus cystic mastopathy). The mapping is approximate, so confirm the match fits the documentation.

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.