Anemia ICD-10 Codes: Documentation, Sequencing, and Billing Guide

When the documentation only mentions “anemia,” it is quick and easy to assign D64.9, Anemia, unspecified. There are situations where assigning D64.9 is completely appropriate. More commonly, the documentation provides enough information to identify the type of anemia as being caused by iron deficiency, by blood loss, by kidney disease, by a vitamin deficiency, etc.

The reason identifying the type of anemia is so important is that there is not just a single diagnosis of “anemia” and a single code for “anemia” in ICD-10-CM. There are many different codes that relate to “anemia” and each code is selected based on the diagnosis of the provider, the reason the anemia is present, the domain and coding notes for that code, and other factors.

This reference guide provides information on the various families of ICD-10 codes that relate to anemia, the type of documentation that supports each family, common problems with code assignment, and problems that increase the workload for coders.

It is imperative that the most current version of ICD-10-CM is used. The first step in the coding process is to look up the code in the Alphabetic Index. The code must also be found in the Tabular List. Always follow the coding and other instructional notes.

The Quick Answer for Anemia ICD-10

The ICD-10-CM code for unspecified anemia is:

• D64.9 Anemia, unspecified
• Code D64.9 is to be used if the anemia type, cause, and/or associated condition are unreported.
• Code D64.9 should not be used if another, more specific code is reported.
• Anemia associated with iron deficiency will require use of the code from the D50 range.
• Deficiency anemia associated with Vitamin B12 will require use of code D51.
• Deficiency anemia associated with folate will require use of code D52.
• Acute post hemorrhagic anemia will require use of code D62.
• Anemia associated with Chronic renal failure will require use of code D63.1.
• Anemia associated with chemotherapy will require use of code D64.81.

When a more specific code is supported by documentation, the more specific code must be assigned, rather than code D64.9.

Start With the Diagnosis, Not the Lab Result

Clilincal laboratory values often assist the provider in making a diagnosis and creating a plan of action. Values are not diagnostic and should not be used to assign a diagnosis by default.

For instance, a low hemoglobin level does not indicate whether the patient has anemia from chronic kidney disease, from iron deficiency, or from blood loss. A low ferritin level does not allow a coder to assign D50.9.

In order to assign a code for anemia:

• Review the assessment and plan and determine the type of anemia documented.
• Evaluate the reason for the anemia. Is it from chronic blood loss? Malignancy? Poor nutrition?
• Look up the anemia in the Alphabetic Index. This will guide the coder to the correct code.
• Check the Tabular List. Ensure the code has not been sequenced to another code. Verify the terminology and check for any modifiers that are required.
• Determine the context of the encounter. For example, in an oncology encounter, the rule for a code may be different than an inpatient encounter.
• When documentation does not clearly indicate a reason for a condition, ask for clarification. It is not appropriate to assign a code to a condition based on a value, medication, or symptom documented on the problem list.

Following these guidelines allows the coder to maintain the integrity of the documentation while supporting the defense of the coding process.

Common Anemia ICD-10-CM Codes at a Glance

The table below includes common codes used in anemia-related documentation. It is not a complete replacement for the official code set.

Other diagnoses of anemia may also be applicable:

• D55-D59: Other conditions may include other hemolytic disorders, thalassemia, and sickle cell disorders.
• D60-D61: Includes other forms of aplastic anemia and pure red cell aplasia.
• D64: Sideroblastic and other specified anemias.

Other less common anemias may also apply.

Iron Deficiency Anemia: D50 Codes Explained

The D50 family is among the most frequently searched anemia code groups. The correct D50 code depends on the provider’s documented diagnosis and the documented cause.

D50.0: Iron Deficiency Anemia Secondary to Chronic Blood Loss

Use D50.0 when the provider documents iron deficiency anemia due to chronic blood loss.

Documentation may include any of the following:

• Iron deficiency anemia due to chronic gastrointestinal (GI) blood loss
• Iron deficiency anemia due to chronic heavy uterine (menstrual) blood loss
• Iron deficiency anemia due to chronic blood loss

Blood loss does not have to be continual to warrant the diagnosis of iron deficiency anemia. The documentation must demonstrate chronicity of the blood loss.

Iron deficiency anemia can occur even if the patient does not have a low serum ferritin level and/or is not taking iron. In addition, chronic blood loss can occur even if the patient is not anemic. The presence of blood loss does not mean that the patient has iron deficiency anemia. The provider makes the determination.

D50.9: Iron Deficiency Anemia, Unspecified

Use code D50.9 when the provider indicates that anemia is due to iron deficiency, but does not provide the reason for the iron deficiency.

This may occur during the course of an evaluation. It may also be the case that no documentation provides a more specific reason. An unspecified code does not indicate an error in coding. An unspecified code may represent the best level of detail supported by the documentation.

D50.8: Other Iron Deficiency Anemias

Use D50.8 only when the provider documents iron deficiency anemia that doesn’t fit the definitions of the other codes (i.e. D50.0, D50.1, D50.9). Always check the Index and Tabular List first to see if an “other” code has been assigned.

Iron Deficiency Versus Iron Deficiency Anemia

Iron deficiency and iron deficiency anemia are very similar and frequently confused.

• Iron deficiency is captured by code E61.1.
• Iron deficiency anemia is represented by codes in the D50. area.

It is important to recognize that these conditions are different and have different coding requirements. If an iron deficiency is documented, it does not permit assignment of a D50. code. The reverse, however, is acceptable. If an iron deficiency anemia is documented, it is permissible to assign the D50. code.

It is important to recognize that just because test results show that a patient is deficient in iron or that the patient’s ferritin levels are low, it does not necessarily mean that a D50. code should be assigned.

Acute Blood Loss Anemia: D62

D62 codes for acute post-hemorrhagic anemia. This code is often used to denote anemia that occurs due to acute blood loss.

Examples of common documentation situations may include the following:

• Bleeding that occurs as a result of an injury
• Post-operative bleeding
• Bleeding that occurs in the gastrointestinal tract
• Another situation in which sudden blood loss is documented

The difference between D62 and D50.0 is mainly the documented anemia type and timing:

Do not make this decision from symptoms, estimated blood loss, or lab changes alone. If the record contains blood-loss information but does not clearly identify the anemia type, a provider query may be appropriate.

Vitamin B12 Deficiency Anemia: D51 Codes

Vitamin B12 deficiency anemia is found within the D51- family of codes. The code is assigned based on the reported cause of the deficiency.

Examples of the codes from this family are:

• D51.0 Vitamin B12 deficiency anemia due to intrinsic factor deficiency
• D51.1 Vitamin B12 deficiency anemia due to selective B12 malabsorption with proteinuria
• D51.2 Transcobalamin II deficiency
• D51.3 Other B12 deficiency anemia due to other causes
• D51.8 Other B12 deficiency anemia
• D51.9 B12 deficiency anemia, unspecified

Documentation from the provider should be reviewed to assess the level of detail provided for the diagnosis. If the provider indicates a diagnosis of B12 deficiency anemia and does not provide additional information, an assumption can be made that the provider is unfamiliar with the ICD-10 coding system, and D51.9 would be assigned.

D51.0 should not be assigned, based on the provision of B12 injections, as this does not explain the reason for the B12 deficiency.

Folate Deficiency and Other Nutritional Anemias

The D52.- family covers folate deficiency anemia, while D53.- addresses certain other nutritional anemias.

D52: Folate Deficiency Anemia

Codes in this section include:

• D52.0 Dietary folate deficiency anemia
• D52.1 Drug-induced folate deficiency anemia
• D52.8 Other folate deficiency anemias
• D52.9 Folate deficiency anemia, unspecified

If the clinician reports folate deficiency anemia is drug-related, consider the Tabular List and the description of the drug’s adverse effect. Do not assume that a medication is related to folate deficiency anemia only because it is associated with folate deficiency.

D53: Other Nutritional Anemias

International Classifications of Diseases, 10th Revision (ICD-10) codes:

• D53.0: Protein deficiency anemia
• D53.1: Other megaloblastic anemias, unspecified
• D53.2: Anemia due to scurvy
• D53.8: Other nutritional anemias, unspecified
• D53.9: Nutritional anemia, unspecified

Code D53.9 may be utilized to indicate nutritional anemia has been documented, and the assigning clinician was unable to determine if the anemia was of the protein deficiency, folate deficiency, vitamin B12 deficiency, or other defined types.

Anemia in Chronic Disease, CKD, and Cancer

Anemia associated with an underlying disease often requires more than one diagnosis code. The documentation should show the relationship between the anemia and the underlying condition when needed, and coders should follow the Index and Tabular List carefully.

D63.1: Anemia in Chronic Kidney Disease

D63.1 is for anemia due to chronic kidney disease. If you use D63.1, you must also assign the appropriate code from the N18.- family of codes for chronic kidney disease.

An example of a good documentation would be:

“Chronic kidney disease Stage 4. Anemia is related to chronic kidney disease and will be managed.”

An example of a poor documentation would be:

“Anemia. Chronic kidney disease.”

You should not use a problem list to help code as there may not be an entry for chronic kidney disease. Also, you should not make inferences about chronic kidney disease based on lab values. Consider the entire document, and the Index entry for D63.1 prior to assigning D63.1.

D63.8: Anemia in Other Chronic Diseases Classified Elsewhere

D63.8 may be used when anemia occurs as a part of another chronic condition that is documented elsewhere.

The other chronic condition should be documented as instructed by its classification. The relationship to anemia should be explained by the provider. If a provider documents a chronic condition and anemia in the same case history and does not explain the relationship, search the ICD-10-CM Index and Tabular List to determine the relationship. If the relationship still cannot be explained by coding conventions, a query should be submitted.

D63.0: Anemia in Neoplastic Disease

Codes from D63 are used to indicate that anemia is documented as being caused by a malignancy.

When anemia associated with the malignancy is the reason for admission, or the malignancy is the reason for the encounter, the malignancy code is assigned first, and D63.0 is assigned second.

Anemia associated with cancer and anemia associated with the effects of cancer treatment are different and should not be coded together.

Chemotherapy-Associated Anemia

D64.81 is the code to use for anemia caused by antineoplastic chemotherapy.

Teams performing Oncology Medical Billing Services must pay special attention to coding sequence. When anemia is caused by an adverse effect of a chemotherapy or biological therapy, the code for the anemia is assigned first, the code for the cancer is assigned next, and the code for the adverse effect is assigned last.

The correct sequence is determined by the reason for the visit, the treatment provided, and the instructions in the latest edition of ICD-10-CM.

Pregnancy, Childbirth, and Postpartum Anemia

Maternal anemia requires additional consideration because codes in Chapter 15 take precedence over other codes.

When anemia occurs during pregnancy, childbirth or the postpartum period and is reported during that specific period, it is assigned an O99.01 series code based on the trimester. Additional codes from Chapter 21 may be assigned to define the type of anemia.

When anemia is documented and is complicating a pregnancy with iron deficiency anemia, the code that defines anemia of pregnancy is assigned, and an additional code defines the type of anemia as iron deficiency.

It is important to note the following:

• Anemia codes are assigned on the maternal record.
• Documentation of trimester should be reviewed.
• A code from the “in childbirth” section should be assigned in appropriate situations.
• Do not assign a general anemia code to replace a specific obstetrical complication code, to determine appropriateness, review the code description.
• Code requirements for gestational age should be reviewed for the encounter in question.

In addition, consider the other components of the postpartum period when anemia is reported. Coding postpartum anemia as an uncomplicated general anemia, (D62) should be reviewed for appropriateness.

Pediatric, Hereditary, Hemolytic, and Aplastic Anemia Coding

Not all anemia coding begins with D50, D63, or D64. Several conditions require their own code families.

Hemolytic and Inherited Disorders

Codes D55-D59 cover disorders because of red blood cell destruction and related conditions because of inheritance and/or acquisition. These conditions include:

• Enzyme disorders
• Thalassemia
• Sickle-cell disorders
• Other inherited hemolytic anemias
• Hemolytic anemias due to other causes

The conditions above should be assigned to conditions other than “anemia” or “low hemoglobin.”

Aplastic Anemia and Pure Red Cell Aplasia

The range D60-D61 encompasses aplastic anemias, including cases of pure red cell aplasia that are the result of an acquired process.

Codes in this range are:

• D61.0 Aplastic anemia, constitutional
• D61.1 Aplastic anemia, drug-induced
• D61.9 Aplastic anemia, unspecified

When there is incomplete or conflicting information, contact the provider for further information as opposed to making an assumption based on a list of the suspected differenial, results of a bone marrow biopsy, or personal judgment.

Anemia of Prematurity

For neonatal records, P61.2, Anemia of prematurity, may apply when documented. Pediatric and newborn coding follows its own chapter-specific rules, so do not automatically apply an adult anemia code family to a neonatal diagnosis.

Documentation Checklist for Providers and Coders

Clear anemia documentation hinges on a thorough clinical narrative. Providing specific assessments and relevant clinical findings will be more helpful than providing a lengthy narrative that does not classify the anemia.

If available, the following information should be provided:

• Specific diagnosis (i.e. Iron deficiency, Thalassemia, etc.)
• Condition that is associated with anemia (i.e. GI cancer, chronic kidney disease, etc.)
• Acute, chronic, recurrent, persistent nature of anemia
• Source of blood loss, if determined
• Any underlying condition (i.e. malignancy, chronic kidney disease, nutritional deficiencies, etc.)
• Any pertinent laboratory/radiologic studies that were interpreted by the physician
• Current medical care, including any recent diagnostic studies/referrals, and/or oical evaluations
• Whether the condition impacts the current visit

Documentation Examples

Insufficient Information

Anemia, possibly from iron deficiency, may continue.

The documentation only supports the diagnosis given. Other anemias (i.e. D64.9) are supported only if there is additional information in the record.

More specific documentation

Evaluation: Iron deficiency anemia is due to chronic blood loss. The client has had Iron studies and the goal of management is to address the anemia. The source of blood loss is being investigated. For practices coordinating Chronic Care Management Services, this level of documentation supports the plan of care for the ongoing follow up of the client.

According to the ICD-10-CM Index and Tabular List, this may support code D50.0.

CKD-related documentation

Assessment: Anemia in chronic kidney disease stage 4.
Review anemia and management per the CKD plan.
The specifics of the anemia management plan, along with appropriate CKD coding, is appreciated for D63.1 review.

When a Provider Query Is Appropriate

A query may help clarify a diagnosis when a record contains pertinent clinical data, but the reason for the diagnosis is not clear.

Examples where a query may be appropriate:

• The diagnosis is recorded as “anemia,” but other chart documentation states the diagnosis is something else.
• Bleeding is documented, but the type of anemia is unknown.
• The record states that the patient has kidney disease (CKD), cancer, or another chronic disease and is anemic.
• The documentation states that the patient is assessed as being anemic, but the plan is to order a hemoglobin/hematocrit (Hb/Hct) test.
• The documentation states that the diagnosis is being worked up and the patient is being seen in an outpatient setting.

Queries should be written to include relevant facts from the case and should be as unbiased as possible.

An example of an appropriate query:

The provider has documented that the patient has anemia and has had recent gastrointestinal (GI) bleeding. Of the documented anemia, was it post bleeding anemia, iron deficiency anemia, some other defined anemia, anemia of an unspecified cause, or is it unknown?

The format of this query leaves it up to the documenting provider to decide on the level of specificity of the diagnosis.

Common Anemia Coding Errors to Avoid

Frequently Asked Questions

What is the ICD-10 code for anemia, unspecified?

D64.9 is the ICD-10-CM code for anemia, unspecified. It is appropriate when the provider documents anemia but the record does not support a more specific type or cause.

What is the difference between D50.9 and D64.9?

D50.9 means iron deficiency anemia, unspecified.
D64.9 means anemia, unspecified.

Use D50.9 only when the provider documents iron deficiency anemia. Do not select it solely from low iron or ferritin results.

What is the difference between D50.0 and D62?

D50.0 is iron deficiency anemia secondary to chronic blood loss.
D62 is acute posthemorrhagic anemia.

The provider’s documentation must establish whether the anemia is related to chronic blood loss or an acute hemorrhagic event.

How is anemia in chronic kidney disease coded?

When documentation and the ICD-10-CM classification support the diagnosis, report D63.1 with the appropriate CKD code from N18.-. Follow all code-first and sequencing instructions in the Tabular List.

Is D64.9 a billable code?

Yes. D64.9 is a complete ICD-10-CM code. It may be reported when anemia is documented but the medical record does not support a more specific anemia diagnosis.

How is chemotherapy-related anemia coded?

When anemia is documented as due to antineoplastic chemotherapy, D64.81 may apply. Verify the encounter reason, neoplasm code, and applicable adverse-effect code before finalizing the sequence.

How is anemia coded during pregnancy?

Use the appropriate code from O99.01- for anemia complicating pregnancy, childbirth, or the puerperium. Add a code from the anemia chapter when needed to identify the documented type of anemia.

Final Takeaway

The correct ICD-10-CM code for anemia is determined by the documented diagnosis of the provider, not by a single laboratory result or by an impersonal, generic entry on the problem list.

Code D64.9 is appropriate to code for unspecified anemia in the absence of documentation to describe specific features of the anemia. Code D50-D64 family anemia codes are to be used to code specific types or causes of anemia. Refer to the ICD-10-CM index and the sequencing instructions to determine the appropriate code.

Documentation flows assist coders in accurately capturing the specific condition of the patient and help the healthcare provider describe the patient’s condition in a precise manner. This, in turn, helps achieve better accuracy in processing health claims.