D51.2 Transcobalamin II deficiency

Billable ICD-10-CM code, FY2026.

Applies from D51 Vitamin B12 deficiency anemia

Excludes1 (never code together)

• vitamin B12 deficiency (E53.8)

MS-DRG index

Defines the logic of DRG(s) 811-812 in MDC 16.

Approximate ICD-9-CM (GEMs)

• 281.1 Other vitamin B12 deficiency anemia (approximate)

Code annotations containing back-references to D51.2

Back-references to D51.2

• Type 1 Excludes: E72.1 Disorders of sulfur-bearing amino-acid metabolism ("transcobalamin II deficiency (D51.2)")

Back-references to D51

• Type 1 Excludes: E53.8 Deficiency of other specified B group vitamins ("vitamin B12 deficiency anemia (D51.-)")
• Code First: M90.5 Osteonecrosis in diseases classified elsewhere ("hemoglobinopathy (D50-D64)")
• Type 1 Excludes: R71 Abnormality of red blood cells ("anemias (D50-D64)")

Diagnosis Index entries for D51.2

• Anemia (essential) (general) (hemoglobin deficiency) (infantile) (primary) (profound) › deficiency › transcobalamin II
• Anemia (essential) (general) (hemoglobin deficiency) (infantile) (primary) (profound) › due to (in) (with) › transcobalamin II deficiency
• Deficiency, deficient › transcobalamine II (anemia)

Nearby codes

• D51 Vitamin B12 deficiency anemia
• D51.0 Vitamin B12 deficiency anemia due to intrinsic factor deficiency
• D51.1 Vitamin B12 deficiency anemia due to selective vitamin B12 malabsorption with proteinuria
• D51.2 Transcobalamin II deficiency (this code)
• D51.3 Other dietary vitamin B12 deficiency anemia
• D51.8 Other vitamin B12 deficiency anemias
• D51.9 Vitamin B12 deficiency anemia, unspecified