2026 ICD-10-CM Diagnosis Code D40.0Neoplasm of uncertain behavior of prostate

ICD-10-CM Codes›C00–D49›D37-D48›D40

ICD-10-CM D40.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D40.0 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of prostate. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 715 through 716, 722 through 724. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.

Code Identity

ICD-10-CM Code
D40.0
Billable Status
Yes — Valid for Submission
Code Describes
Neoplasm of uncertain behavior of prostate
Short Description
Neoplasm of uncertain behavior of prostate
Same as the full description in the CMS dataset.
Parent Code
D40
Neoplasm of uncertain behavior of male genital organs

Code Classification

ChapterC00–D49Neoplasms
SectionD37-D48Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
CategoryD40Neoplasm of uncertain behavior of male genital organs
This CodeD40.0Neoplasm of uncertain behavior of prostate

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Neoplasm of uncertain behavior of prostate
  • Phyllodes tumor of prostate

Clinical ClassificationClinical

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

CCSR NEO072
Neoplasms of unspecified nature or uncertain behavior
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
prostate (gland)C61C79.82D07.5D29.1D40.0D49.59

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 D40.0 to ICD-9-CMHistory

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

ICD-9-CM
236.5 Unc behav neo prostate
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 D40.0Overview

Is D40.0 (Neoplasm of uncertain behavior of male genital organs) a billable code?

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

What MS-DRG does D40.0 group to?

When neoplasm of uncertain behavior of prostate is the principal diagnosis on an inpatient stay, it groups to MS-DRG 715, 716, 722, 723, 724, with relative weights from 0.6117 to 2.2373 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D40.0?

Under the General Equivalence Mappings, neoplasm of uncertain behavior of prostate converts to ICD-9-CM 236.5 (unc behav neo prostate). 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.