2026 ICD-10-CM Diagnosis Code D39.12Neoplasm of uncertain behavior of left ovary

ICD-10-CM Codes›C00–D49›D37-D48›D39

ICD-10-CM D39.12
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D39.12 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of left ovary. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 736 through 741, 754 through 756. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.

Code Identity

ICD-10-CM Code
D39.12
Billable Status
Yes — Valid for Submission
Code Describes
Neoplasm of uncertain behavior of left ovary
Short Description
Neoplasm of uncertain behavior of left ovary
Same as the full description in the CMS dataset.
Parent Code
D39.1
Neoplasm of uncertain behavior of ovary

Code Classification

ChapterC00–D49Neoplasms
SectionD37-D48Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
CategoryD39Neoplasm of uncertain behavior of female genital organs
This CodeD39.12Neoplasm of uncertain behavior of left ovary

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral neoplasm of uncertain behavior of ovaries
  • Mucinous borderline tumor of bilateral ovaries
  • Mucinous borderline tumor of left ovary
  • Mucinous borderline tumor of ovary
  • Mucinous borderline tumor of right ovary
  • Neoplasm of low malignant potential behavior of left ovary
  • Neoplasm of low malignant potential behavior of ovary
  • Neoplasm of uncertain behavior of left ovary
  • Neoplasm of uncertain behavior of right ovary

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.
corpusC56.C79.6D07.39D27.D39.1D49.59
corpus › albicansC56.C79.6D07.39D27.D39.1D49.59
ovaryC56.C79.6D07.39D27.D39.1D49.59

Patient EducationClinical

Ovarian Disorders

The ovaries are a pair of female reproductive glands that make eggs and female hormones. Women have one ovary on each side of the uterus (where a fetus grows during pregnancy). Each ovary is about the size and shape of an almond.

The full article covers:

  • What are ovaries?
  • What are the types of ovarian disorders?
  • What causes ovarian disorders?
  • What are the symptoms of ovarian disorders?
  • How are ovarian disorders diagnosed?
  • What are the treatments for ovarian disorders?

Read the full article at MedlinePlus

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

Convert D39.12 to ICD-9-CMHistory

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

ICD-9-CM
236.2 Unc behav neo ovary
Approximate The match is approximate rather than exact.

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 D39.12Overview

Is D39.12 (Neoplasm of uncertain behavior of ovary) a billable code?

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

What MS-DRG does D39.12 group to?

When neoplasm of uncertain behavior of left ovary is the principal diagnosis on an inpatient stay, it groups to MS-DRG 736, 737, 738, 739, 740, 741, 754, 755, 756, with relative weights from 0.9605 to 3.5745 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D39.12?

Under the General Equivalence Mappings, neoplasm of uncertain behavior of left ovary converts to ICD-9-CM 236.2 (unc behav neo ovary). The mapping is approximate, so confirm the match fits the documentation.

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.