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

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 2026 (October 1, 2025 through September 30, 2026) 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

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

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

Questions About R92.342Overview

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, 2025 through September 30, 2026.

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 0.6050 to 1.0416 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.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.