Anemia ICD-10 Code: Complete Coding Guide for 2026

Accurate anemia coding starts with clear provider documentation and a correct understanding of the underlying cause. For physicians, hospitals, clinics, and other healthcare providers, selecting the right ICD-10-CM code helps support accurate claims, appropriate reimbursement, and accurate billing. ICD-10-CM includes specific codes for anemia related to iron deficiency, blood loss, chronic kidney disease (CKD), cancer, chemotherapy, and other conditions.

Using an incorrect, incomplete, or unspecified code when more detailed documentation is available can contribute to claim denials, payment issues, and audit concerns.

For 2026, healthcare providers and their billing teams should use the ICD-10-CM code set applicable to the date of service and review current coding guidelines, sequencing requirements, CPT/HCPCS rules, and payer-specific policies. This guide covers the most commonly used anemia ICD-10-CM codes, documentation requirements, and billing considerations to help providers maintain accurate and compliant claims.

What Is the ICD-10 Code for Anemia?

The most frequently used ICD-10-CM code for anemia, unspecified, is D64.9 — Anemia, unspecified. It is only appropriate if the provider documents anemia with no other supported type or cause. D64.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.

Do not automatically assign D64.9 if a patient has low hemoglobin or low hematocrit. The diagnosis must be established and documented by the provider. The FY 2026 Official Guidelines state that abnormal laboratory findings are not automatically coded as diagnoses unless the provider documents their clinical significance.

Common alternatives include:

• D50.0 — Iron deficiency anemia secondary to blood loss (chronic)
• D50.9 — Iron deficiency anemia, unspecified
• D51.9 — Vitamin B12 deficiency anemia, unspecified
• D52.9 — Folate deficiency anemia, unspecified
• D62 — Acute posthemorrhagic anemia
• D63.0 — Anemia in neoplastic disease
• D63.1 — Anemia in chronic kidney disease
• D63.8 — Anemia in other chronic diseases classified elsewhere
• D64.81 — Anemia due to antineoplastic chemotherapy
• D64.89 — Other specified anemias
• D64.9 — Anemia, unspecified

The correct selection depends on the provider’s documented diagnosis and the instructions attached to the specific code.

Which ICD-10-CM Codes Apply in 2026?

The applicable ICD-10-CM version depends on the patient’s encounter date. CMS identifies the FY 2026 ICD-10-CM files for encounters from October 1, 2025 through September 30, 2026, with an additional update effective April 1, 2026.

For a claim with a 2026 date of service, the billing team should therefore confirm:

1. The patient’s date of service.
2. The ICD-10-CM version effective for that date.
3. Whether an April 1, 2026 update applies.
4. The current CPT and HCPCS code sets used by the payer.
5. Any payer-specific medical-necessity or coverage policy.
6. Whether the claim requires additional diagnosis codes.

The official FY 2026 coding guidelines emphasize that ICD-10-CM code selection should reflect the documentation and that the highest level of specificity supported by the medical record should be reported.

Anemia ICD-10 Codes: Master Reference Table

The following are among the most relevant anemia ICD-10-CM codes encountered in physician, hospital, laboratory, oncology, nephrology, hematology, and medical billing workflows.

Condition or Scenario	ICD-10-CM Code	Official Description
Iron deficiency anemia due to chronic blood loss	D50.0	Iron deficiency anemia secondary to blood loss (chronic)
Sideropenic dysphagia	D50.1	Sideropenic dysphagia
Other iron deficiency anemia	D50.8	Other iron deficiency anemias
Unspecified iron deficiency anemia	D50.9	Iron deficiency anemia, unspecified
Vitamin B12 deficiency anemia	D51.9	Vitamin B12 deficiency anemia, unspecified
Dietary folate deficiency anemia	D52.0	Dietary folate deficiency anemia
Drug-induced folate deficiency anemia	D52.1	Drug-induced folate deficiency anemia
Folate deficiency anemia, unspecified	D52.9	Folate deficiency anemia, unspecified
Protein deficiency anemia	D53.0	Protein deficiency anemia
Other megaloblastic anemia	D53.1	Other megaloblastic anemias, not elsewhere classified
Nutritional anemia, unspecified	D53.9	Nutritional anemia, unspecified
G6PD-related anemia	D55.0	Anemia due to glucose-6-phosphate dehydrogenase [G6PD] deficiency
Alpha thalassemia	D56.0	Alpha thalassemia
Beta thalassemia	D56.1	Beta thalassemia
Thalassemia trait	D56.3	Thalassemia minor
Thalassemia, unspecified	D56.9	Thalassemia, unspecified
Sickle-cell disease without crisis	D57.1	Sickle-cell disease without crisis
Acquired hemolytic anemia	D59.9	Acquired hemolytic anemia, unspecified
Aplastic anemia, unspecified	D61.9	Aplastic anemia, unspecified
Acute blood-loss anemia	D62	Acute posthemorrhagic anemia
Anemia in neoplastic disease	D63.0	Anemia in neoplastic disease
Anemia in chronic kidney disease	D63.1	Anemia in chronic kidney disease
Anemia in other chronic disease	D63.8	Anemia in other chronic diseases classified elsewhere
Hereditary sideroblastic anemia	D64.0	Hereditary sideroblastic anemia
Secondary sideroblastic anemia due to disease	D64.1	Secondary sideroblastic anemia due to disease
Secondary sideroblastic anemia due to drugs/toxins	D64.2	Secondary sideroblastic anemia due to drugs and toxins
Other sideroblastic anemia	D64.3	Other sideroblastic anemias
Congenital dyserythropoietic anemia	D64.4	Congenital dyserythropoietic anemia
Chemotherapy-induced anemia	D64.81	Anemia due to antineoplastic chemotherapy
Other specified anemia	D64.89	Other specified anemias
Unspecified anemia	D64.9	Anemia, unspecified

CMS’s FY 2026 code files confirm the principal anemia categories and specific codes, including the D50-D64 range.

Important distinction: D63.1 vs. D64.9

D63.1 is used for anemia in chronic kidney disease when the provider establishes the relationship. It is not interchangeable with unspecified anemia. The ICD-10-CM Tabular instructions require the underlying CKD to be coded first.

For example, a documented case of anemia due to CKD may require:

1. N18.- — Appropriate chronic kidney disease stage
2. D63.1 — Anemia in chronic kidney disease

The exact CKD code depends on the documented stage.

How to Select the Correct Anemia ICD-10 Code

1. Start with the provider’s diagnosis

The first question is not “What does the CBC show?” It is “What diagnosis did the provider establish?”

For example:

Documentation:
“Anemia, unspecified.”

A supported code may be D64.9.

But if the provider documents:

“Iron deficiency anemia due to chronic GI blood loss,”

the coder should investigate the specific documentation and applicable coding instructions rather than defaulting to D64.9.

The FY 2026 guidelines state that the medical record should describe the patient’s condition and that coding should be performed to the highest level of specificity supported by documentation.

2. Identify the type of anemia

Look for documentation specifying:

• Iron deficiency
• Vitamin B12 deficiency
• Folate deficiency
• Acute blood loss
• Chronic blood loss
• Hemolytic anemia
• Aplastic anemia
• Sideroblastic anemia
• Thalassemia
• Sickle-cell disease
• Anemia associated with CKD
• Anemia associated with malignancy
• Chemotherapy-induced anemia
• Other specified anemia

The type often determines the correct ICD-10-CM category.

3. Determine the documented cause

Cause matters because two patients can both have “anemia” but require completely different coding.

For example:

• Chronic blood loss → consider D50.0 when iron deficiency anemia secondary to chronic blood loss is documented.
• CKD-related anemia → D63.1 plus the applicable CKD code.
• Neoplastic disease-associated anemia → D63.0 with the neoplasm coded first.
• Antineoplastic chemotherapy-induced anemia → D64.81, subject to the applicable coding instructions.

4. Do not confuse acute blood loss with chronic blood loss

D62 represents acute posthemorrhagic anemia.

Chronic blood loss associated with iron deficiency is represented differently, including D50.0 when the documented diagnosis supports iron deficiency anemia secondary to chronic blood loss.

That distinction is important because the two conditions may have very different clinical and billing circumstances.

5. Check the underlying disease

Some anemia codes are manifestation codes that require the underlying condition to be reported.

For D63.0, the neoplasm is coded first.

For D63.1, the underlying CKD is coded first.

For D63.8, the underlying disease is coded first when instructed by the Tabular List.

6. Review Tabular List instructions

Never stop at the Alphabetic Index.

Check for:

• Code first
• Use additional code
• Code also
• Excludes1
• Excludes2
• Additional specificity
• Combination-code instructions

These instructions can change the final claim sequence.

7. Apply setting-specific rules

Outpatient and inpatient coding rules are not identical, particularly when the diagnosis is uncertain.

For inpatient hospital admissions, the FY 2026 guidelines allow certain uncertain diagnoses documented at discharge—such as probable, suspected, likely, possible, or still-to-be-ruled-out conditions—to be coded as though established. This rule applies to qualifying inpatient admissions, not ordinary outpatient encounters.

8. Check payer medical necessity

A technically correct ICD-10 code does not automatically guarantee payment.

The diagnosis must support the service being billed under the applicable payer’s policy.

For example, anemia-related laboratory testing, iron therapy, erythropoiesis-stimulating agents, and infusion services can have separate coverage and documentation requirements.

Anemia Documentation Checklist

Documentation directly affects code specificity, medical necessity, reimbursement, and audit defensibility.

Documentation Item	Why It Matters
✔ Confirmed anemia diagnosis	Establishes the condition being treated or evaluated
✔ Specific anemia type	Supports a more specific ICD-10-CM code
✔ Underlying cause	May determine the code category and sequencing
✔ Acute vs. chronic status	Helps distinguish conditions such as D62 from chronic blood-loss anemia
✔ Relationship to CKD	Supports D63.1 when documented
✔ Relationship to malignancy	Helps distinguish D63.0 from chemotherapy-induced anemia
✔ Relationship to chemotherapy	May support D64.81
✔ Relevant treatment	Helps establish the reason for services
✔ Clinical significance	Helps prevent coding abnormal findings as diagnoses without provider interpretation
✔ Final assessment	Provides the basis for diagnosis-code assignment

Weak documentation

“Low Hgb. Iron low. Anemia?”

This does not clearly establish the final diagnosis or its cause.

Better documentation

“Iron deficiency anemia.”

This establishes a more specific diagnosis than an isolated abnormal laboratory result.

Strong documentation

“Iron deficiency anemia secondary to chronic gastrointestinal blood loss.”

This provides both the anemia type and documented cause, allowing the coder to evaluate the appropriate code and any additional condition that should be reported.

The coder should not independently convert a low hemoglobin, low ferritin, or abnormal MCV into a definitive anemia diagnosis without appropriate provider documentation.

High-Risk Anemia Coding and Sequencing Rules

Anemia in chronic kidney disease

When the provider documents anemia in CKD, D63.1 is the anemia code, while the underlying CKD is also reported.

The Tabular List instruction is to code the underlying CKD first.

Example

A patient has documented CKD stage 4 and anemia due to CKD.

Possible sequence:

1. N18.4 — Chronic kidney disease, stage 4
2. D63.1 — Anemia in chronic kidney disease

The exact sequence and diagnosis combination should be checked against the current Tabular List and payer policy.

For certain Medicare ESA claims, CMS coverage guidance specifically expects dual diagnosis coding for anemia of CKD and the CKD stage.

Anemia in neoplastic disease

D63.0 is used for anemia in neoplastic disease when the anemia is associated with the malignancy.

The underlying neoplasm is coded first.

Example

A patient has a documented malignancy and anemia attributed to the neoplasm.

Possible approach:

1. Appropriate C00-D49 neoplasm code
2. D63.0 — Anemia in neoplastic disease

Do not substitute D63.0 for chemotherapy-induced anemia when the provider documents that chemotherapy caused the anemia.

Anemia due to antineoplastic chemotherapy

D64.81 identifies anemia due to antineoplastic chemotherapy.

This should be distinguished from D63.0, which represents anemia in neoplastic disease. CMS code references identify D64.81 as antineoplastic chemotherapy-induced anemia and distinguish it from anemia in neoplastic disease.

Drug-adverse-effect coding can also involve T36-T50 codes with the appropriate fifth or sixth character when applicable. The FY 2026 guidelines explain that an adverse effect of a correctly administered drug is coded with the nature of the adverse effect followed by the appropriate adverse-effect code.

Secondary sideroblastic anemia

For D64.1, the underlying disease is coded first.

For drug- or toxin-related secondary sideroblastic anemia, D64.2 has specific sequencing instructions involving the responsible drug or toxin and, where applicable, an adverse-effect code.

This is an example of why selecting a generic anemia code without reviewing the Tabular List can produce an incorrect claim.

Acute posthemorrhagic anemia

D62 is used for acute posthemorrhagic anemia.

It should not be used merely because a patient has anemia and a history of bleeding. The documentation needs to support the acute posthemorrhagic condition.

Chronic blood loss and iron deficiency anemia follow different coding pathways.

Anemia Coding Examples

Clinical Documentation	Suggested Code Approach	Main Coding Point
“Anemia, unspecified”	D64.9	Use when no more specific anemia diagnosis is documented
“Iron deficiency anemia”	D50.9 when unspecified as to subtype/cause	Do not automatically use D64.9
“Iron deficiency anemia due to chronic blood loss”	D50.0	Chronic blood-loss relationship is documented
“Acute posthemorrhagic anemia”	D62	Distinguish acute blood loss from chronic blood loss
“Vitamin B12 deficiency anemia”	Appropriate D51.- code	Select the documented B12-related subtype
“Folate deficiency anemia”	Appropriate D52.- code	Select the documented folate-related subtype
“Anemia due to CKD stage 4”	N18.4 + D63.1	Underlying CKD is coded first
“Anemia in neoplastic disease”	Neoplasm code + D63.0	Malignancy is coded first
“Anemia due to antineoplastic chemotherapy”	D64.81 plus applicable additional coding	Do not confuse with D63.0
Low Hgb only, no provider diagnosis	Do not infer anemia	Review documentation/query process

The code choices above are examples of coding approaches, not automatic assignments for every patient. The final code must be based on the complete record and current coding instructions.

Can Anemia Be Coded From Lab Results Alone?

Generally, no. A coder should not independently establish anemia from a low hemoglobin or hematocrit.

The FY 2026 Official Guidelines specifically state that abnormal laboratory, imaging, pathology, and other diagnostic findings are not coded and reported unless the provider indicates their clinical significance. If the abnormal finding is clinically significant and needs to be reported, a provider query may be appropriate.

This distinction matters in anemia billing because laboratory results such as:

• Hemoglobin
• Hematocrit
• MCV
• MCH
• RDW
• Ferritin
• Serum iron
• TIBC
• Transferrin
• Vitamin B12
• Folate

can help clinicians evaluate a patient, but they do not automatically give the coder permission to assign a definitive anemia diagnosis.

When a provider query may be appropriate

A query may be considered when:

• The record contains clinically significant abnormal findings.
• The provider has evaluated the findings.
• The diagnosis is unclear or incomplete.
• A more specific diagnosis would accurately reflect the clinical picture.
• The query can be written in a compliant, non-leading manner.

The purpose is clarification, not to manufacture a more favorable reimbursement diagnosis.

Outpatient vs. Inpatient Anemia Coding

Outpatient Coding

For outpatient encounters, uncertain diagnoses such as “probable,” “suspected,” or “possible” are generally not coded as confirmed conditions. Code the documented confirmed diagnosis, symptoms, or abnormal findings as appropriate.

Inpatient Coding

For qualifying inpatient admissions, diagnoses documented at discharge as probable, suspected, likely, or possible may be coded as established conditions under the applicable ICD-10-CM guidelines.

Common Anemia Coding Mistakes

Using D64.9 when a specific diagnosis is documented

If the provider clearly documents iron deficiency anemia, CKD-related anemia, chemotherapy-induced anemia, or another specific type, automatically using D64.9 loses available specificity.

Correct approach: Review the documentation and Tabular List for the most specific supported code.

Coding anemia from laboratory values alone

A low hemoglobin does not automatically authorize the coder to assign D64.9.

Correct approach: Look for provider documentation establishing the diagnosis.

Confusing D63.1 and D64.9

D63.1 describes anemia in CKD. D64.9 is unspecified anemia.

Correct approach: Determine whether the provider documented a causal relationship between anemia and CKD.

Confusing D63.0 and D64.81

Anemia associated with malignancy is not necessarily the same as anemia caused by chemotherapy.

Correct approach: Follow the provider’s documented causal relationship and applicable Tabular List instructions.

Missing the underlying disease

Some anemia codes require the underlying condition to be coded.

Correct approach: Review code-first and related instructions before finalizing the claim.

Using the wrong blood-loss code

Acute posthemorrhagic anemia and chronic blood-loss iron deficiency anemia are not interchangeable.

Correct approach: Determine whether the provider documented acute posthemorrhagic anemia or chronic blood-loss-related iron deficiency anemia.

Ignoring date-of-service code validity

An ICD-10-CM code can change between annual or interim updates.

Correct approach: Validate the code against the version effective on the encounter date. CMS provides separate FY 2026 files and an April 1, 2026 update.

Assuming a payer will reimburse a correct diagnosis code

A valid diagnosis code is only one component of a claim.

Correct approach: Review the payer’s coverage, medical-necessity, authorization, frequency, and documentation requirements.

CPT, HCPCS, and Billing Codes Commonly Associated With Anemia

Anemia claims can involve evaluation and management services, laboratory testing, venipuncture, infusions, injections, medications, and treatment monitoring. There is not one universal CPT code for “anemia.”

The procedure code depends on what was actually performed.

Commonly encountered CPT® categories may include:

Service	Common CPT®/HCPCS Examples	Billing Consideration
Venipuncture	36415	Used when the applicable specimen collection service is separately reportable
CBC with differential	85025	Used when the performed laboratory service meets the code definition
CBC without differential	85027	Appropriate only when the documented test matches the code
Hemoglobin	85018	Depends on the actual laboratory service
Hematocrit	85014	Depends on the actual laboratory service
Iron	83540	Iron studies may be relevant to anemia evaluation
Iron-binding capacity	83550	Used for the applicable laboratory test
Ferritin	82728	Commonly used in iron-status evaluation
Transferrin	84466	May be used as part of iron-status evaluation
Vitamin B12	82607	Used when the corresponding laboratory test is performed
Folate	82746	Used for the applicable folate assay
E/M office or outpatient visit	99202-99205, 99211-99215	Level depends on the documented service and current CPT® rules
Infusion services	Examples include 96365, 96366, when applicable	Must match the actual infusion service and payer rules
Drug administration/injection	Applicable administration codes	Selection depends on drug, route, and service performed

CMS has published coverage guidance identifying 82728, 83540, 83550, and 84466 as laboratory services used in the evaluation of iron deficiency, anemia, and iron overload conditions.

These are not automatically payable simply because D64.9 is on the claim. Medical necessity depends on the clinical circumstances, documentation, payer policy, and applicable coverage requirements.

What about iron infusion and anemia treatment codes?

When anemia treatment involves intravenous iron or another medication, the claim may contain:

• A drug HCPCS code
• Drug administration CPT code
• Appropriate anemia diagnosis code
• Underlying condition code when required
• Applicable modifiers
• Units based on the amount administered
• Documentation supporting medical necessity

The exact HCPCS code depends on the medication actually administered. Drug codes and payer policies can change, so billing teams should verify the current HCPCS file and the payer’s policy rather than maintaining a static list indefinitely.

For ESA therapy, CMS coverage guidance illustrates how diagnosis coding can be particularly important. For certain erythropoiesis-stimulating agents used for anemia of CKD, CMS policies can require D63.1 together with an appropriate CKD diagnosis and may impose additional claim requirements.

Best Practices for Clean Anemia Claims

Build diagnosis-specific documentation prompts

EHR templates can prompt providers to document:

• Type of anemia
• Etiology
• Acute or chronic status
• Relationship to CKD
• Relationship to malignancy
• Relationship to chemotherapy
• Blood-loss source when clinically established
• Treatment being provided
• Clinical significance

The objective is not to force providers toward a particular diagnosis. It is to make clinically relevant documentation easier to capture.

Create targeted coding edits

A claim-scrubbing system can flag situations such as:

• D64.9 used repeatedly when a more specific diagnosis appears elsewhere in the record.
• D63.1 submitted without an appropriate CKD diagnosis.
• D63.0 submitted without the underlying neoplasm.
• Chemotherapy-related anemia coded inconsistently with treatment documentation.
• Laboratory services billed without supporting diagnosis information where payer policy requires it.
• Invalid or outdated diagnosis codes based on the service date.

Review payer policies before treatment

Medical necessity can differ by payer and service.

This is especially relevant for:

• Iron studies
• IV iron
• ESAs
• Hematology services
• Oncology services
• Transfusions
• Infusion services
• Repeated laboratory monitoring

CMS’s Medicare Coverage Database provides payer-specific billing and coding guidance for particular services, but Medicare policy should not automatically be treated as the rule for every commercial payer.

Audit unspecified-code usage

A high volume of D64.9 claims may be a useful audit signal.

It does not automatically mean the coding is wrong. Some records genuinely support unspecified anemia. However, a pattern of D64.9 usage can justify reviewing whether providers are documenting the anemia type and cause clearly enough.

Query instead of assuming

When the record contains clinically relevant information but the diagnosis or relationship is unclear, a compliant query can help resolve the documentation gap.

The coder should not independently create a causal relationship such as “anemia due to CKD” merely because both diagnoses appear in the chart.

Frequently Asked Questions

What is the ICD-10 code for anemia?

The ICD-10-CM code for anemia, unspecified is D64.9. However, D64.9 should be used only when the provider documents anemia without enough specificity to assign a more specific anemia code. Other codes apply to iron deficiency, vitamin deficiency, blood loss, CKD, malignancy, chemotherapy, and other causes.

What is the ICD-10 code for iron deficiency anemia?

The appropriate code depends on the documented type and cause. D50.9 is iron deficiency anemia, unspecified, while D50.0 identifies iron deficiency anemia secondary to chronic blood loss. Other D50.- codes may apply to specified conditions.

What is the ICD-10 code for anemia in CKD?

D63.1 is the ICD-10-CM code for anemia in chronic kidney disease. The underlying CKD code should also be reported, and the Tabular List instructs coders to code the CKD first.

Can D64.9 be used with a low hemoglobin result?

Not automatically. A coder should not independently establish anemia from a low hemoglobin or hematocrit. The FY 2026 guidelines distinguish abnormal laboratory findings from provider-established diagnoses.

What is the ICD-10 code for acute blood-loss anemia?

The code is D62 — Acute posthemorrhagic anemia. It should be distinguished from chronic blood-loss-related iron deficiency anemia, which may fall under D50.0 when the documentation supports that diagnosis.

What is the difference between D63.0 and D64.81?

D63.0 represents anemia in neoplastic disease, while D64.81 represents anemia due to antineoplastic chemotherapy. The documented relationship and applicable coding instructions determine which code is appropriate.

Can anemia be coded from ferritin or iron results alone?

No. Laboratory results can provide clinical evidence, but they do not automatically establish a diagnosis for coding purposes. The provider must document the diagnosis or its clinical significance according to the applicable coding rules.

What CPT codes are commonly used for anemia testing?

Depending on the actual service, anemia-related claims may include CPT codes such as 85025, 85027, 85018, 85014, 82728, 83540, 83550, 84466, 82607, 82746, and 36415. The correct code depends on the test or service performed, and current CPT guidance and payer policy should be checked before billing.

Does the correct anemia ICD-10 code guarantee payment?

No. Correct diagnosis coding is necessary for accurate billing, but payment can also depend on medical necessity, payer coverage, authorization, frequency limits, documentation, coding combinations, modifiers, and other claim requirements.

When should a provider be queried for anemia?

A query may be appropriate when the record contains clinically significant information but does not clearly establish the diagnosis, cause, or relationship needed for accurate coding. The query should clarify the record rather than lead the provider toward a reimbursement-driven answer.

Conclusion

Accurate Anemia ICD-10 Code selection starts with clear provider documentation and the correct diagnosis. Specific conditions such as iron deficiency anemia, acute blood-loss anemia, and anemia related to CKD or cancer require appropriate ICD-10-CM codes and sequencing.

For accurate claims and fewer denials, billing teams should verify documentation, CPT/HCPCS codes, medical necessity, and payer requirements. Utah Billing Service, a trusted medical billing company in Utah, helps healthcare providers manage accurate billing, coding, and revenue cycle processes.