ICD-10 Code D74.9 – Methemoglobinemia, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D74.9 – Methemoglobinemia, unspecified
What it is
D74.9 identifies methemoglobinemia when the record does not specify a cause or type. It means hemoglobin has been altered so it cannot carry oxygen normally, but the documentation is nonspecific.
Clinical signs
Clinical features vary; refer to documentation. Commonly described findings include cyanosis, shortness of breath, fatigue, headache, or low oxygen saturation that does not improve as expected.
When to use this code
Use D74.9 when the provider documents methemoglobinemia without naming an acquired, congenital, or drug-induced form. It also fits when the chart confirms the disorder but does not identify the underlying cause. Check documentation if the record suggests a more specific subtype.
Do not use for
Do not use this code when the record specifies congenital, hereditary, or drug-induced methemoglobinemia. Also avoid it if the documentation only mentions hypoxemia or cyanosis without a diagnosis of methemoglobinemia.
Coding tip
Code the most specific methemoglobinemia type documented; use D74.9 only when the record remains unspecified.