2026 ICD-10-CM Diagnosis Code D75.839Thrombocytosis, unspecified

ICD-10-CM Codes›D50–D89›D70-D77›D75

ICD-10-CM D75.839
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D75.839 is a billable ICD-10-CM diagnosis code for thrombocytosis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 814 through 816. Coders also document this condition as platelet count above reference range. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Coagulation and hemorrhagic disorders.

Code Identity

ICD-10-CM Code
D75.839
Billable Status
Yes — Valid for Submission
Code Describes
Thrombocytosis, unspecified
Short Description
Thrombocytosis, unspecified
Same as the full description in the CMS dataset.
Parent Code
D75.83
Thrombocytosis

Code Classification

ChapterD50–D89Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
SectionD70-D77Other disorders of blood and blood-forming organs
CategoryD75Other and unspecified diseases of blood and blood-forming organs
This CodeD75.839Thrombocytosis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Platelet count above reference range
  • Thrombocytosis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Thrombocythemia NOS
  • Thrombocytosis NOS

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.

    • Thrombocythemia(hemorrhagic)
    • Thrombocytosis

Clinical ClassificationClinical

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

CCSR BLD006
Coagulation and hemorrhagic disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Thrombocythemia, Essential

    a clinical syndrome characterized by repeated spontaneous hemorrhages and a remarkable increase in the number of circulating platelets.

  • Thrombocytosis

    increased numbers of platelets in the peripheral blood. (dorland, 27th ed)

Patient EducationClinical

Platelet Disorders

Platelets, also known as thrombocytes, are blood cells. They form in your bone marrow, a sponge-like tissue in your bones. Platelets play a major role in blood clotting. Normally, when one of your blood vessels is injured, you start to bleed.

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement D75.839 replaces the following previously assigned code(s):

  • D75.89 - Other specified diseases of blood and blood-forming organs
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D75.839Overview

Is D75.839 (Thrombocytosis) a billable code?

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

What MS-DRG does D75.839 group to?

When thrombocytosis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 814, 815, 816, with relative weights from 0.6320 to 2.1267 depending on complications. Higher weights mean higher Medicare reimbursement.

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.