2027 ICD-10-CM Diagnosis Code N65.1Disproportion of reconstructed breast

ICD-10-CM Codes›N00–N99›N60-N65›N65

ICD-10-CM N65.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N65.1 is a billable ICD-10-CM diagnosis code for disproportion of reconstructed 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 breasts asymmetrical. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nonmalignant breast conditions.

Code Identity

ICD-10-CM Code
N65.1
Billable Status
Yes — Valid for Submission
Code Describes
Disproportion of reconstructed breast
Short Description
Disproportion of reconstructed breast
Same as the full description in the CMS dataset.
Parent Code
N65
Deformity and disproportion of reconstructed breast

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN60-N65Disorders of breast
CategoryN65Deformity and disproportion of reconstructed breast
This CodeN65.1Disproportion of reconstructed breast

Code EditsBilling

Medicare Code Editor checks that affect claim validity for N65.1.

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.

  • Breasts asymmetrical
  • Disproportion of reconstructed breast
  • Disproportion of reconstructed left breast
  • Disproportion of reconstructed right breast
  • Symmetry of breasts - finding

Instructional NotesGuidance

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

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Breast asymmetry between native breast and reconstructed breast
  • Disproportion between native breast and reconstructed breast

Excludes1

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

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 N65.1, its category, or a range that includes it.

Excludes1 4

These codes carry an Excludes1 note naming N65.1: they are not reported together with it, unless the two conditions are unrelated.

  • N62 Hypertrophy of breast
    disproportion of reconstructed breast (N65.1)
  • N64.81 Ptosis of breast
    ptosis of native breast in relation to reconstructed breast (N65.1)
  • N64.82 Hypoplasia of breast
    hypoplasia of native breast in relation to reconstructed breast (N65.1)
  • Z42.1 Encounter for breast reconstruction following mastectomy
    deformity and disproportion of reconstructed breast (N65.1-)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to 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

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 N65.1 to ICD-9-CMHistory

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

ICD-9-CM
612.1 Disproportn reconst brst
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N65.1Overview

What is the ICD-10 code for disproportion of reconstructed breast?

The ICD-10-CM code for disproportion of reconstructed breast is N65.1 (sometimes written as N651). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is N65.1 (Deformity and disproportion of reconstructed breast) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report disproportion of reconstructed breast on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does N65.1 group to?

When disproportion of reconstructed 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 N65.1 be reported for?

The Medicare Code Editor checks disproportion of reconstructed 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 N65.1?

Under the General Equivalence Mappings, disproportion of reconstructed breast converts to ICD-9-CM 612.1 (disproportn reconst brst). The mapping is a direct match.