2026 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 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N64.82 is a billable ICD-10-CM diagnosis code for hypoplasia of 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). 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).

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Micromastia

Type 1 Excludes

  • congenital absence of breast Q83.0
  • hypoplasia of native breast in relation to reconstructed breast N65.1

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Hypoplasia, hypoplastic
      • breast (areola)
    • Micromastia

Clinical ClassificationClinical

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

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

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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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About N64.82Overview

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, 2025 through September 30, 2026.

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 0.6050 to 1.0416 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.

What is the ICD-9 equivalent of N64.82?

Under the General Equivalence Mappings, hypoplasia of breast converts to ICD-9-CM 611.82 (hypoplasia of breast). The mapping is a direct match.

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.