2027 ICD-10-CM Diagnosis Code R92.342Mammographic extreme density, left breast

ICD-10-CM Codes›R00–R99›R90-R94›R92

ICD-10-CM R92.342
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

R92.342 is a billable ICD-10-CM diagnosis code for mammographic extreme density, 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. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R92.342
Billable Status
Yes — Valid for Submission
Code Describes
Mammographic extreme density, left breast
Short Description
Mammographic extreme density, left breast
Same as the full description in the CMS dataset.
Parent Code
R92.34
Mammographic extreme density of breast

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR90-R94Abnormal findings on diagnostic imaging and in function studies, without diagnosis
CategoryR92Abnormal and inconclusive findings on diagnostic imaging of breast
This CodeR92.342Mammographic extreme density, left breast

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to R92.342: its own notes plus those printed at R92.3, block R90-R94, and Chapter 18. 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 Block R90-R94 Abnormal findings on diagnostic imaging and in function studies, without diagnosis applies to 64 codes
  • nonspecific abnormal findings on diagnostic imaging by computerized axial tomography [CAT scan]
  • nonspecific abnormal findings on diagnostic imaging by magnetic resonance imaging [MRI][NMR]
  • nonspecific abnormal findings on diagnostic imaging by positron emission tomography [PET scan]
  • nonspecific abnormal findings on diagnostic imaging by thermography
  • nonspecific abnormal findings on diagnostic imaging by ultrasound [echogram]
  • nonspecific abnormal findings on diagnostic imaging by X-ray examination

Excludes1

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

From Block R90-R94 Abnormal findings on diagnostic imaging and in function studies, without diagnosis applies to 64 codes
  • abnormal findings on antenatal screening of mother (O28.-)
  • diagnostic abnormal findings classified elsewhere - see Alphabetical Index

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 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • abnormal findings on antenatal screening of mother (O28.-)
  • certain conditions originating in the perinatal period (P04-P96)
  • signs and symptoms classified in the body system chapters
  • signs and symptoms of breast (N63, N64.5)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From R92.3 Mammographic density found on imaging of breast applies to 13 codes
  • if applicable, inconclusive mammogram (R92.2)

Notes

General instructions on how these codes are used.

From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
  • Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated 'not otherwise specified', 'unknown etiology' or 'transient'. The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.
  • The conditions and signs or symptoms included in categories R00-R94 consist of:
  • (a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
  • (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
  • (c) provisional diagnosis in a patient who failed to return for further investigation or care;
  • (d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
  • (e) cases in which a more precise diagnosis was not available for any other reason;
  • (f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name R92.342, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming R92.342: they are not reported together with it, unless the two conditions are unrelated.

  • R22 Localized swelling, mass and lump of skin and subcutaneous tissue
    abnormal findings on diagnostic imaging (R90-R93) names R90-R93, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming R92.342: its condition is not part of those codes, and both may be reported when the patient has both.

  • N64.5 Other signs and symptoms in breast
    abnormal findings on diagnostic imaging of breast (R92.-) names R92.-, which includes this code

Clinical ClassificationClinical

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

CCSR SYM017
Abnormal findings without diagnosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Mammography

A mammogram is an x-ray picture of the breast. Health care providers use mammograms to look for early signs of breast cancer that can't be felt during a breast exam. There are two types of mammograms: screening mammograms and diagnostic mammograms.

The full article covers:

  • What is a mammogram?
  • What is a screening mammogram?
  • What is a diagnostic mammogram?
  • How is a mammogram done?
  • What happens if my mammogram is not normal?

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement R92.342 replaces the following previously assigned code(s):

  • R92.2 - Inconclusive mammogram
FY 2024AddedAdded to the ICD-10-CM code setEffective October 1, 2023.
FY 2025–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About R92.342Overview

What is the ICD-10 code for mammographic extreme density, left breast?

The ICD-10-CM code for mammographic extreme density, left breast is R92.342 (sometimes written as R92342). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is R92.342 (Mammographic extreme density of breast) a billable code?

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

What MS-DRG does R92.342 group to?

When mammographic extreme density, 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.

Can R92.342 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the mammographic extreme density, left breast is established, that condition takes the principal position instead.

Can R92.342 be reported with a code from O28?

Not as a rule. The Excludes1 note at block R90-R94, which applies to R92.342, lists "abnormal findings on antenatal screening of mother (O28.-)". 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).