D51.1 ICD-10-CM Code: Vitamin B12 deficiency anemia due to selective vitamin B12 malabsorption with proteinuria
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FY 2026 Apr update / Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89) / Nutritional anemias (D50-D53)
D51.1
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceVitamin B12 deficiency anemia due to selective vitamin B12 malabsorption with proteinuria
This is a type of anemia (low red blood cell count) caused by the body's inability to properly absorb vitamin B12 from food, which also results in protein being lost in the urine. The malabsorption of B12 leads to insufficient red blood cell production, causing fatigue and weakness.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Imerslund (Gräsbeck) syndrome
- Megaloblastic hereditary anemia
Excludes 2
Official- deficiency of other B group vitamins (E53-)
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for D51.1 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for D51.1 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for D51.1 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for D51.1 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for D51.1 in this effective period.
Buddy Documentation Tip
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is D51.1 an HCC code?
No. D51.1 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
D51.1 is the ICD-10-CM diagnosis code for vitamin b12 deficiency anemia due to selective vitamin b12 malabsorption with proteinuria. This is a type of anemia (low red blood cell count) caused by the body's inability to properly absorb vitamin B12 from food, which also results in protein being lost in the urine. The malabsorption of B12 leads to insufficient red blood cell production, causing fatigue and weakness. D51.1 sits in the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89), within the section covering nutritional anemias (d50-d53).
D51.1 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Verify documentation specifies both the selective B12 malabsorption AND the presence of proteinuria, as both conditions must be present to use this specific code.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for D51.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify documentation specifies both the selective B12 malabsorption AND the presence of proteinuria, as both conditions must be present to use this specific code
- •Do not use this code if the B12 deficiency is due to other causes such as pernicious anemia, dietary deficiency, or post-gastrectomy; each has its own specific ICD-10-CM code