ICD-10 Code D51.8 – Other vitamin B12 deficiency anemias (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D51.8 – Other vitamin B12 deficiency anemias
What it is
D51.8 identifies anemia caused by vitamin B12 deficiency when the case does not fit other specific B12 deficiency anemia codes. Use it for documented B12-related anemia with a more specific subtype not stated.
Clinical signs
Typical findings include anemia with symptoms such as fatigue, pallor, and weakness. Clinical features vary; refer to documentation for the exact cause, since B12 deficiency may also involve neurologic or hematologic changes.
When to use this code
Use this code when the record clearly states other vitamin B12 deficiency anemia or a comparable B12 deficiency anemia that is not otherwise classified. It may also apply when the clinician documents B12 deficiency anemia without a more specific subtype.
Do not code from suspicion alone; confirm the diagnosis in the chart. If the documentation names a different B12-related anemia category, choose the more specific ICD-10-CM code instead.
Do not use for
Do not use D51.8 for anemia from folate deficiency, iron deficiency, or unspecified anemia without B12 deficiency. Check documentation if the cause of anemia is unclear.
Coding tip
Look for the exact provider wording; when a more specific B12 deficiency anemia is documented, code that diagnosis instead of D51.8.