ICD-10 Code D59.5 – Paroxysmal nocturnal hemoglobinuria [Marchiafava-Micheli] (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D59.5 – Paroxysmal nocturnal hemoglobinuria [Marchiafava-Micheli]
What it is
D59.5 identifies paroxysmal nocturnal hemoglobinuria, an acquired disorder that causes red blood cells to break down too easily. It is a rare hemolytic condition linked to a defect in blood cell surface protection.
Clinical signs
Typical findings include hemolysis, dark urine, fatigue, and anemia. Clinical features vary; refer to documentation, especially when thrombosis, abdominal pain, or marrow failure are mentioned.
When to use this code
Use D59.5 when the record clearly documents paroxysmal nocturnal hemoglobinuria or Marchiafava-Micheli disease. You may also use it when the provider confirms PNH as the cause of hemolysis, hemoglobinuria, or related complications.
Check documentation if the note only says unexplained anemia, hematuria, or hemolysis without naming PNH. Code the confirmed diagnosis, not a suspected condition.
Do not use for
Do not use this code for other hemolytic anemias, inherited red cell disorders, or isolated hematuria. If the chart does not support PNH, check documentation.
Coding tip
Look for the exact diagnosis name or a provider statement linking hemolysis or thrombosis to PNH before assigning D59.5.