2026 ICD-10-CM Diagnosis Code D72.821Monocytosis (symptomatic)

ICD-10-CM Codes›D50–D89›D70-D77›D72

ICD-10-CM D72.821
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D72.821 is a billable ICD-10-CM diagnosis code for monocytosis (symptomatic). 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Diseases of white blood cells.

Code Identity

ICD-10-CM Code
D72.821
Billable Status
Yes — Valid for Submission
Code Describes
Monocytosis (symptomatic)
Short Description
Monocytosis (symptomatic)
Same as the full description in the CMS dataset.
Parent Code
D72.82
Elevated white blood cell count

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
CategoryD72Other disorders of white blood cells
This CodeD72.821Monocytosis (symptomatic)

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Blood monocyte number above reference range
  • Chronic idiopathic monocytosis
  • Monocyte count - finding
  • Monocyte count outside reference range
  • Monocytoid disorder
  • Monocytosis
  • Reactive monocytosis

Tabular List NotesGuidance

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

Type 1 Excludes

  • infectious mononucleosis B27

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.

    • Monocytosis(symptomatic)

Clinical ClassificationClinical

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

CCSR BLD007
Diseases of white blood cells
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Clonal Cytopenia with Monocytosis of Undetermined Significance|CCMUS

    a myelodysplastic/myeloproliferative neoplasm that fulfills the diagnostic criteria of clonal monocytosis of undetermined significance and is associated with cytopenia.

  • Clonal Monocytosis of Undetermined Significance|CMUS

    a myelodysplastic/myeloproliferative neoplasm characterized by the presence of persistent monocytosis, presence of at least one myeloid neoplasm-associated mutation, absence of significant dysplasia or increased blasts in the bone marrow, absence of morphologic findings suggestive of chronic myelomonocytic leukemia in the bone marrow, and absence of history of a reactive condition that would explain the persistent monocytosis.

  • Monocytosis

    abnormally high level of monocytes in the blood.

Patient EducationClinical

Blood Disorders

Your blood is living tissue made up of liquid and solids. The liquid part, called plasma, is made of water, salts and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells and platelets.

Read the full article at MedlinePlus

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

Convert D72.821 to ICD-9-CMHistory

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

ICD-9-CM
288.63 Monocytosis-symptomatic
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 D72.821Overview

Is D72.821 (Elevated white blood cell count) a billable code?

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

What MS-DRG does D72.821 group to?

When monocytosis (symptomatic) 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.

What is the ICD-9 equivalent of D72.821?

Under the General Equivalence Mappings, monocytosis (symptomatic) converts to ICD-9-CM 288.63 (monocytosis-symptomatic). 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.