ICD-10 Code D51.0 – Vitamin B12 deficiency anemia due to intrinsic factor deficiency (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D51.0 – Vitamin B12 deficiency anemia due to intrinsic factor deficiency
What it is
This code identifies pernicious anemia, a vitamin B12 deficiency caused by lack of intrinsic factor. Use it when the anemia is documented as due to intrinsic factor deficiency, not simply low B12 intake.
Clinical signs
Common findings include macrocytic anemia, fatigue, pallor, and sometimes glossitis or neurologic symptoms such as numbness or gait changes. Clinical features vary; refer to documentation.
When to use this code
Use D51.0 when the provider documents vitamin B12 deficiency anemia caused by intrinsic factor deficiency or pernicious anemia. It also fits when the record clearly links the anemia to impaired intrinsic factor production or absorption. Check documentation if the cause is unclear.
Do not use for
Do not use this code for B12 deficiency from poor diet, malabsorption without intrinsic factor deficiency, or other specified causes. If the note does not identify intrinsic factor deficiency, check documentation.
Coding tip
Look for explicit wording such as “pernicious anemia” or “intrinsic factor deficiency” before assigning D51.0.