2026 ICD-10-CM Diagnosis Code D74.0Congenital methemoglobinemia
ICD-10-CM Codes›D50–D89›D70-D77›D74
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Chronic Condition
D74.0 is a billable ICD-10-CM diagnosis code for congenital methemoglobinemia. 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 24 closely related codes. Coders also document this condition as autosomal recessive congenital methemoglobinemia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified hematologic conditions.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Autosomal recessive congenital methemoglobinemia
- Autosomal recessive congenital methemoglobinemia type I
- Autosomal recessive congenital methemoglobinemia type II
- Congenital methemoglobinaema with defective methemoglobin-reducing system
- Congenital methemoglobinemia
- Congenital methemoglobinemia with abnormal methemoglobins
- Hemoglobin M disease
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Congenital NADH-methemoglobin reductase deficiency
- Hemoglobin-M [Hb-M] disease
- Methemoglobinemia, hereditary
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
diaphorase deficiency D74.0
M D74.0
congenital D74.0
enzymatic (congenital) D74.0
Hb M disease D74.0
hereditary D74.0
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Congenital Methemoglobinemia
methemoglobinemia inherited in an autosomal recessive pattern. it is caused by deficiency of the enzyme nadh methemoglobin reductase or the presence of abnormal hemoglobin m. it presents with cyanosis early in life. there is no evidence of cardiopulmonary disease present.
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 D74.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D74.0Overview
What is the ICD-10 code for congenital methemoglobinemia?
The ICD-10-CM code for congenital methemoglobinemia is D74.0 (sometimes written as D740). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is D74.0 (Methemoglobinemia) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report congenital methemoglobinemia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does D74.0 group to?
When congenital methemoglobinemia 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.
Is D74.0 a CC or MCC?
CMS lists D74.0 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 24 closely related codes in its exclusion list.
What is the ICD-9 equivalent of D74.0?
Under the General Equivalence Mappings, congenital methemoglobinemia converts to ICD-9-CM 289.7 (methemoglobinemia). The mapping is approximate, so confirm the match fits the documentation.
