2026 ICD-10-CM Diagnosis Code D74.9Methemoglobinemia, unspecified

ICD-10-CM Codes›D50–D89›D70-D77›D74

ICD-10-CM D74.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D74.9 is a billable ICD-10-CM diagnosis code for methemoglobinemia, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 811 through 812. Coders also document this condition as methemoglobinemia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified hematologic conditions.

Code Identity

ICD-10-CM Code
D74.9
Billable Status
Yes — Valid for Submission
Code Describes
Methemoglobinemia, unspecified
Short Description
Methemoglobinemia, unspecified
Same as the full description in the CMS dataset.
Parent Code
D74
Methemoglobinemia

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
CategoryD74Methemoglobinemia
This CodeD74.9Methemoglobinemia, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Methemoglobinemia

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.

    • Methemoglobinemia

Clinical ClassificationClinical

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

CCSR BLD010
Other specified and unspecified hematologic conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Methemoglobinemia

    the presence of methemoglobin in the blood, resulting in cyanosis. a small amount of methemoglobin is present in the blood normally, but injury or toxic agents convert a larger proportion of hemoglobin into methemoglobin, which does not function reversibly as an oxygen carrier. methemoglobinemia may be due to a defect in the enzyme nadh methemoglobin reductase (an autosomal recessive trait) or to an abnormality in hemoglobin m (an autosomal dominant trait). (dorland, 27th ed)

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 D74.9 to ICD-9-CMHistory

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

ICD-9-CM
289.7 Methemoglobinemia
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 D74.9Overview

Is D74.9 (Methemoglobinemia) a billable code?

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

What MS-DRG does D74.9 group to?

When methemoglobinemia, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 811, 812, with relative weights from 0.9182 to 1.4043 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D74.9?

Under the General Equivalence Mappings, methemoglobinemia, unspecified converts to ICD-9-CM 289.7 (methemoglobinemia). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.