2027 ICD-10-CM Diagnosis Code N64.82Hypoplasia of breast

ICD-10-CM Codes›N00–N99›N60-N65›N64

ICD-10-CM N64.82
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N64.82 is a billable ICD-10-CM diagnosis code for hypoplasia of 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). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nonmalignant breast conditions.

This medical diagnosis code is frequently used in OB/GYN medical specialties to designate conditions such lump in breast and other disorders of the breast.

Code Identity

ICD-10-CM Code
N64.82
Billable Status
Yes — Valid for Submission
Code Describes
Hypoplasia of breast
Short Description
Hypoplasia of breast
Same as the full description in the CMS dataset.
Parent Code
N64.8
Other specified disorders of breast

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN60-N65Disorders of breast
CategoryN64Other disorders of breast
This CodeN64.82Hypoplasia of breast

Code EditsBilling

Medicare Code Editor checks that affect claim validity for N64.82.

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).

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N64.82: its own notes plus those printed at N64, 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.

  • Micromastia

Excludes1

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

On N64.82 itself
  • congenital absence of breast (Q83.0)
  • hypoplasia of native breast in relation to reconstructed breast (N65.1)
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 N64 Other disorders of breast applies to 13 codes
  • mechanical complication of breast prosthesis and implant (T85.4-)
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 N64.82, its category, or a range that includes it.

Excludes2 2

These codes carry an Excludes2 note naming N64.82: its condition is not part of those codes, and both may be reported when the patient has both.

  • Q83 Congenital malformations of breast
    hypoplasia of breast (N64.82)
  • Q83 Congenital malformations of breast
    micromastia (N64.82)

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

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Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert N64.82 to ICD-9-CMHistory

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

ICD-9-CM
611.82 Hypoplasia of breast
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 N64.82Overview

What is the ICD-10 code for hypoplasia of breast?

The ICD-10-CM code for hypoplasia of breast is N64.82 (sometimes written as N6482). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is N64.82 (Other specified disorders of breast) a billable code?

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

What MS-DRG does N64.82 group to?

When hypoplasia of 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 N64.82 be reported for?

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

Can N64.82 be reported with Q83.0?

Not as a rule. The Excludes1 note on N64.82 lists "congenital absence of breast (Q83.0)". 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).