What is ICD-10 code D55.8?

D55.8 is the ICD-10-CM diagnosis code for Other anemias due to enzyme disorders. A type of anemia caused by various enzyme disorders not specifically classified elsewhere. These enzyme deficiencies affect red blood cell function and survival. D55.8 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. D55.8 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. D55.8 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. D55.8 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for D55.8?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. D55.8 was a payment HCC under V24 (Coagulation Defects and Other Specified Hematological Disorders) but the V28 recalibration removed it from the risk adjustment model. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting D55.8?

Use this code for enzyme-related anemias that don't fit into more specific categories Document the specific enzyme disorder in the medical record even if using this catch-all code Because D55.8 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

D55.8: Other anemias due to enzyme disorders —

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupD55.8Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89) / Hemolytic anemias (D55-D59)

D55.8

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Other anemias due to enzyme disorders

A type of anemia caused by various enzyme disorders not specifically classified elsewhere. These enzyme deficiencies affect red blood cell function and survival.

Buddy Insight

This code captures hemolytic anemias resulting from enzyme disorders that do not fit into the more specific subcategories of glycolytic, glutathione, or nucleotide metabolism defects.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Mapped

HCC 48

Coagulation Defects and Other...

RAF 0.209

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 48

Coagulation Defects and Other...

RAF 0.0

RXHCC

Not risk-adjusted for this model/period.

RAF 0

Code Trumping

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Code Book Path

Official

D55Anemia due to enzyme disorders

D55.8Other anemias due to enzyme disorders

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for D55.8 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for D55.8 in this effective period.

Related Child Codes

Official

D55.0Anemia due to glucose-6-phosphate dehydrogenase [G6PD] deficiency

D55.1Anemia due to other disorders of glutathione metabolism

D55.2Anemia due to disorders of glycolytic enzymes

D55.3Anemia due to disorders of nucleotide metabolism

D55.9Anemia due to enzyme disorder, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for D55.8 in this effective period.

Excludes 1

Official

drug-induced enzyme deficiency anemia (D59.2)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for D55.8 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for D55.8 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for D55.8 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation should describe the enzyme disorder as specifically as possible, including any enzyme assay results, genetic testing, or pathologic findings.

Record hemolysis markers, hemoglobin levels, transfusion history, and complications such as cholelithiasis or iron overload.

The provider should document why a more specific D55 subcategory code does not apply.

MEAT Support

HCC Buddy guidance

Documentation should describe the enzyme disorder as specifically as possible, including any enzyme assay results, genetic testing, or pathologic findings.

Record hemolysis markers, hemoglobin levels, transfusion history, and complications such as cholelithiasis or iron overload.

The provider should document why a more specific D55 subcategory code does not apply.

Audit Caution

HCC Buddy guidance

This code has no V28 HCC mapping. Do not use D55.8 as a convenience code when more specific classification is possible within D55.0-D55.3 or D55.

Query the provider for additional specificity before defaulting to this category. Ensure the condition is documented as enzyme-related and not a membrane disorder (D58) or acquired hemolytic anemia (D59).

Common Mistakes

HCC Buddy guidance

D55.8 vs. D55.9 (Anemia due to enzyme disorder, unspecified) -

use D55.8 when the enzyme disorder is identified but does not fit specific subcategories, vs. D55.9 when the enzyme disorder is completely unidentified. D55.8 vs. D58.8 (Other specified hereditary hemolytic anemias) -

D58.8 covers non-enzyme hereditary causes like membrane disorders. D55.8 vs. D55.0-D55.3 -

use more specific codes when the metabolic pathway is clearly identified.

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 D55.8 an HCC code?

Yes. D55.8 maps to Coagulation Defects and Other Specified Hematological Disorders under the V24 model but is not retained in V28.

HCC Category Mapping

V24HCC 48, Coagulation Defects and Other Specified Hematological Disorders

0.209

ESRDHCC 48, Coagulation Defects and Other Specified Hematological Disorders

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

MEAT Criteria for D55.8

For D55.8to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed D55.8 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

D55.8 is the ICD-10-CM diagnosis code for other anemias due to enzyme disorders. A type of anemia caused by various enzyme disorders not specifically classified elsewhere. These enzyme deficiencies affect red blood cell function and survival. D55.8 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 hemolytic anemias (d55-d59).

Under the older CMS-HCC V24 model, D55.8 maps to Coagulation Defects and Other Specified Hematological Disorders (HCC 48) with a community, non-dual, aged base RAF weight of 0.209. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Use this code for enzyme-related anemias that don't fit into more specific categories. Because D55.8 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for D55.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code for enzyme-related anemias that don't fit into more specific categories
•Document the specific enzyme disorder in the medical record even if using this catch-all code

Clinical Significance

This code captures hemolytic anemias resulting from enzyme disorders that do not fit into the more specific subcategories of glycolytic, glutathione, or nucleotide metabolism defects. These may include disorders of the hexose monophosphate shunt (other than Glucose-6-phosphate dehydrogenase deficiency) or other rare enzymopathies affecting red blood cell viability. While individually rare, they collectively represent important causes of chronic hemolysis that require ongoing clinical management.

Documentation Requirements

✓Documentation should describe the enzyme disorder as specifically as possible, including any enzyme assay results, genetic testing, or pathologic findings.
✓Record hemolysis markers, hemoglobin levels, transfusion history, and complications such as cholelithiasis or iron overload.
✓The provider should document why a more specific D55 subcategory code does not apply.

Commonly Confused Codes

•D55.8 vs. D55.9 (Anemia due to enzyme disorder, unspecified) -
•use D55.8 when the enzyme disorder is identified but does not fit specific subcategories, vs. D55.9 when the enzyme disorder is completely unidentified. D55.8 vs. D58.8 (Other specified hereditary hemolytic anemias) -
•D58.8 covers non-enzyme hereditary causes like membrane disorders. D55.8 vs. D55.0-D55.3 -
•use more specific codes when the metabolic pathway is clearly identified.