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D51.2

D51.2Transcobalamin II deficiency

Billable / specific codeICD-10-CM

D51.2 is a billable, specific ICD-10-CM code for transcobalamin ii deficiency. It is valid for submission on a claim.

Other codes that can never be billed with D51.2

These codes carry an Excludes1 note pointing at D51.2. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading D51.2 alone.

  • E72.1Disorders of sulfur-bearing amino-acid metabolism

Risk adjustment

D51.2 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

D51.2 is named in 4 Medicare coverage policies 4 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56416Billing and Coding: Assays for Vitamins and Metabolic Function
  • A56464Billing and Coding: Flow Cytometry
  • A56675Billing and Coding: Homocysteine Level, Serum
  • A57755Billing and Coding: Vitamin B<sub>12</sub> Injections

How D51.2 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to D51.2.

  • Deficiency, deficienttranscobalamine II(anemia)
  • Anemiadeficiencytranscobalamin II
  • Anemiadue totranscobalamin II deficiency

Related codes at this level

Codes that share D51. If D51.2 is not quite right, the correct code is usually one of these.

Questions about D51.2

Is D51.2 a billable ICD-10-CM code?
Yes. D51.2 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does D51.2 sit in the tabular list?
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89), in the block Nutritional anemias (D50-D53).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.