2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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 2027 (October 1, 2026 through September 30, 2027) 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N60.12: its own notes plus those printed at N60.1, N60, block N60-N65, and Chapter 14. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From N60 Benign mammary dysplasia applies to 21 codes
  • fibrocystic mastopathy

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From N60.1 Diffuse cystic mastopathy applies to 3 codes
  • diffuse cystic mastopathy with epithelial proliferation (N60.3-)
From Block N60-N65 Disorders of breast applies to 60 codes
  • disorders of breast associated with childbirth (O91-O92)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 14 (N00-N99) Diseases of the genitourinary system applies to 838 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name N60.12, its category, or a range that includes it.

Excludes2 3

These codes carry an Excludes2 note naming N60.12: its condition is not part of those codes, and both may be reported when the patient has both.

  • D24 Benign neoplasm of breast
    benign cyst of breast (N60.-) names N60.-, which includes this code
  • D24 Benign neoplasm of breast
    benign mammary dysplasia (N60.-) names N60.-, which includes this code
  • D24 Benign neoplasm of breast
    fibrocystic disease of breast (N60.-) names N60.-, which includes this code

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

  • Breast Fibrocystic Change

    fibrosis associated with cyst formation in the breast parenchyma.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N60.12Overview

What is the ICD-10 code for diffuse cystic mastopathy of left breast?

The ICD-10-CM code for diffuse cystic mastopathy of left breast is N60.12 (sometimes written as N6012). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 0.6014 to 0.9971 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.

Can N60.12 be reported with a code from N60.3?

Not as a rule. The Excludes1 note at N60.1, which applies to N60.12, lists "diffuse cystic mastopathy with epithelial proliferation (N60.3-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).