What is ICD-10 code D55.0?

D55.0 is the ICD-10-CM diagnosis code for Anemia due to glucose-6-phosphate dehydrogenase [G6PD] deficiency. It belongs to the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89). D55.0 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. D55.0 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. D55.0 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. D55.0 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 D55.0?

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. D55.0 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 D55.0?

Specify if hemolytic crisis is present, as this affects severity coding Document any triggering factors (medications, infections, fava bean exposure) in the medical record for complete clinical picture Because D55.0 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.

2026 ICD-10-CM D55.0: Anemia due

ICD-10-CM Code View

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Code lookupD55.0Effective 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)

D55.0

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

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

A type of anemia caused by a deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD), which normally helps protect red blood cells from damage. People with this condition may experience hemolytic crises when exposed to certain medications, infections, or foods like fava beans.

Buddy Insight

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Mapped

HCC 48

Coagulation Defects and Other...

RAF 0.192

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

Mapped

HCC 48

Coagulation Defects and Other...

RAF 0.063

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

D55Anemia due to enzyme disorders

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

Inclusion Terms

Official

Favism
G6PD deficiency anemia

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for D55.0 in this effective period.

Related Child Codes

Official

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

D55.8Other anemias due to enzyme disorders

D55.9Anemia due to enzyme disorder, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for D55.0 in this effective period.

Excludes 1

Official

glucose-6-phosphate dehydrogenase (G6PD) deficiency without anemia (D75.A)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for D55.0 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for D55.0 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for D55.0 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Document the confirmed diagnosis of Glucose-6-phosphate dehydrogenase deficiency with laboratory confirmation (enzyme activity assay), current hemolytic crisis status if applicable, known triggers, and baseline hemoglobin levels.

Record any history of hemolytic episodes, medications to avoid, and ongoing monitoring plan.

If a hemolytic crisis is occurring, document the triggering agent and severity.

MEAT Support

HCC Buddy guidance

Record any history of hemolytic episodes, medications to avoid, and ongoing monitoring plan.

If a hemolytic crisis is occurring, document the triggering agent and severity.

Audit Caution

HCC Buddy guidance

This code does not map to V28 HCC, meaning it will not be captured for risk adjustment under the V28 model -- only V

Ensure documentation clearly distinguishes Glucose-6-phosphate dehydrogenase deficiency from other enzyme deficiencies. Do not code this condition only during acute hemolytic episodes; it is a chronic inherited condition that should be captured at every encounter where clinically relevant and addressed.

Common Mistakes

HCC Buddy guidance

D55.0 vs. D55.1 (Anemia due to other glutathione metabolism disorders) -

Glucose-6-phosphate dehydrogenase deficiency is specifically in the glutathione pathway but has its own code. D55.0 vs. D59.0 (Drug-induced autoimmune hemolytic anemia) -

D59.0 is autoimmune-mediated, not enzyme-deficiency mediated. D55.0 vs. D58.9 (Hereditary hemolytic anemia, unspecified) -

use D55.0 when Glucose-6-phosphate dehydrogenase deficiency is specifically confirmed.

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 D55.0 an HCC code?

Yes. D55.0 maps to Coagulation Defects and Other Specified Hematological Disorders under the V24 model but is not retained in V28.

Code: D55.0
Description: Anemia due to glucose-6-phosphate dehydrogenase [G6PD] deficiency
HCC (V28): No CMS-HCC V28 mapping
RAF: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

V24HCC 48, Coagulation Defects and Other Specified Hematological Disorders

0.192

ESRDHCC 48, Coagulation Defects and Other Specified Hematological Disorders

0.063

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. 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.

Work D55.0 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for D55.0

For D55.0to 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 D55.0 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

D55.0 is the ICD-10-CM diagnosis code for anemia due to glucose-6-phosphate dehydrogenase [g6pd] deficiency. A type of anemia caused by a deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD), which normally helps protect red blood cells from damage. People with this condition may experience hemolytic crises when exposed to certain medications, infections, or foods like fava beans. D55.0 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, D55.0 maps to Coagulation Defects and Other Specified Hematological Disorders (HCC 48) with a community, non-dual, aged base RAF weight of 0.192. 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.

Specify if hemolytic crisis is present, as this affects severity coding. Because D55.0 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 D55.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Specify if hemolytic crisis is present, as this affects severity coding
•Document any triggering factors (medications, infections, fava bean exposure) in the medical record for complete clinical picture

Clinical Significance

Glucose-6-phosphate dehydrogenase deficiency is the most common human enzymopathy, affecting over 400 million people worldwide, predominantly males of African, Mediterranean, and Southeast Asian descent. It causes episodic hemolytic anemia triggered by oxidative stressors including certain medications (sulfonamides, antimalarials, nitrofurantoin), infections, and fava bean ingestion. Between crises, patients may be completely asymptomatic, making documentation of the underlying condition essential for risk capture.

Documentation Requirements

✓Document the confirmed diagnosis of Glucose-6-phosphate dehydrogenase deficiency with laboratory confirmation (enzyme activity assay), current hemolytic crisis status if applicable, known triggers, and baseline hemoglobin levels.
✓Record any history of hemolytic episodes, medications to avoid, and ongoing monitoring plan.
✓If a hemolytic crisis is occurring, document the triggering agent and severity.

Excludes 1, Do NOT code together

glucose-6-phosphate dehydrogenase (G6PD) deficiency without anemia (D75.A)

Commonly Confused Codes

•D55.0 vs. D55.1 (Anemia due to other glutathione metabolism disorders) -
•Glucose-6-phosphate dehydrogenase deficiency is specifically in the glutathione pathway but has its own code. D55.0 vs. D59.0 (Drug-induced autoimmune hemolytic anemia) -
•D59.0 is autoimmune-mediated, not enzyme-deficiency mediated. D55.0 vs. D58.9 (Hereditary hemolytic anemia, unspecified) -
•use D55.0 when Glucose-6-phosphate dehydrogenase deficiency is specifically confirmed.