2026 ICD-10-CM Diagnosis Code N42.9Disorder of prostate, unspecified

ICD-10-CM Codes›N00–N99›N40-N53›N42

ICD-10-CM N42.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N42.9 is a billable ICD-10-CM diagnosis code for disorder of prostate, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 729 through 730. The code is restricted by the Medicare Code Editor to adult patients (age 15 through 124). Coders also document this condition as disorder of prostate. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified male genital disorders.

Code Identity

ICD-10-CM Code
N42.9
Billable Status
Yes — Valid for Submission
Code Describes
Disorder of prostate, unspecified
Short Description
Disorder of prostate, unspecified
Same as the full description in the CMS dataset.
Parent Code
N42
Other and unspecified disorders of prostate

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN40-N53Diseases of male genital organs
CategoryN42Other and unspecified disorders of prostate
This CodeN42.9Disorder of prostate, unspecified

Code EditsBilling

Medicare Code Editor checks that affect claim validity for N42.9.

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.

  • Disorder of prostate
  • Lesion of prostate
  • Problem of prostate

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.

    • Disease, diseased
      • prostate
    • Disorder(of)
      • prostate
    • Irregular, irregularity
      • prostate
    • Palpable
      • prostate

Clinical ClassificationClinical

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

CCSR GEN016
Other specified male genital disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Prostate Diseases

The prostate is a gland in the male reproductive system. It lies just below the bladder. It makes fluid that is part of semen.

The full article covers:

  • What is the prostate?
  • What are prostate diseases?
  • Who is more likely to develop prostate diseases?
  • What are the symptoms of prostate diseases?
  • How are prostate diseases diagnosed?

Read the full article at MedlinePlus

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

Convert N42.9 to ICD-9-CMHistory

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

ICD-9-CM
602.9 Prostatic disorder NOS
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 N42.9Overview

Is N42.9 (Other and unspecified disorders of prostate) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report disorder of prostate, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N42.9 group to?

When disorder of prostate, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 729, 730, with relative weights from 0.6720 to 1.0587 depending on complications. Higher weights mean higher Medicare reimbursement.

Who can N42.9 be reported for?

The Medicare Code Editor checks disorder of prostate, unspecified 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 N42.9?

Under the General Equivalence Mappings, disorder of prostate, unspecified converts to ICD-9-CM 602.9 (prostatic disorder NOS). The mapping is a direct match.

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.