D64.9ICD-10-CM

Anemia, unspecified

BillableUnchanged since 2015Displaced by any documented cause

How the code is built

Chapter

Diseases of the blood and blood-forming organs

What ICD-10 code D64.9 means

D64.9 is the ICD-10-CM code for anemia, unspecified. It applies when a provider documents anemia without identifying the type, the mechanism, or an underlying disease that caused it, which is the ordinary situation at a first visit when a complete blood count returns abnormal, and the workup has not been completed.

The Alphabetic Index sends the unqualified term anemia here, along with several entries a coder might not expect, including low hemoglobin, low hematocrit, and hemoglobin deficiency. Those index entries make D64.9 easy to reach and easy to over-report.

Attribute	Detail
Code	D64.9
Descriptor	Anemia, unspecified
Chapter	Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
Block	Aplastic and other anemias and other bone marrow failure syndromes
Category	D64, other anemias
Billable	Yes
Excludes1	Refractory anemia (D46.-) and refractory anemia with excess blasts in transformation (C92.0-)
Index entries	Anemia NOS, idiopathic, normocytic, progressive, low hemoglobin, low hematocrit, oligocythemia

The descriptor has not changed in any fiscal year since ICD-10-CM took effect in 2015. The exposure on this code is not a stale reference. It is that D64.9 is the easiest anemia code to reach and the hardest to defend once a workup exists in the chart.

2Code structure

The cause axis, and the sequencing question

D64.9 has no subdivisions. Everything that makes an anemia specific sits outside this code, and it sits in two different directions that behave differently on a claim.

The cause axis

a different category entirely

No type or cause stated

D64.9

This code

Iron, B12, folate, or other nutritional deficiency

D50 to D53

Hereditary or acquired hemolysis

D55 to D59

Bone marrow failure or aplasia

D60 to D61

Acute blood loss

D62

A chronic disease classified elsewhere

D63

Sideroblastic, chemotherapy-induced, or other specified

D64.0 to D64.89

The sequencing question

whether the anemia leads or follows

Situation	Order
Anemia stands alone	D64.9 first, nothing to sequence against
Anemia in chronic kidney disease	The CKD code first, then D63.1
Anemia in neoplastic disease	The neoplasm first, then D63.0
Anemia in another chronic disease	The underlying disease first, then D63.8
Type 2 myocardial infarction caused by anemia	The anemia first, then I21.A1

That last row reverses the pattern and catches coders out. A type 2 MI from demand ischemia carries a code-first instruction naming anemia across the full D50.0 to D64.9 range. The anemia is the cause, so the anemia leads and the infarction follows.

3Clinical picture

Clinical findings documented under D64.9

A record supporting this code describes reduced oxygen-carrying capacity, confirmed on a blood count, without identifying which mechanism produced it.

General

Fatigue, weakness, reduced exercise tolerance

Cardiopulmonary

Dyspnea on exertion, palpitations, tachycardia, soft systolic murmur

Neurologic

Dizziness, lightheadedness, headache

Examination

Pallor of skin or mucous membranes, cold intolerance

Laboratory

Reduced hemoglobin and hematocrit on a complete blood count

What keeps an encounter at D64.9 is the absence of a mechanism. Once red cell indices, iron studies, B12 and folate levels, or a reticulocyte count point somewhere and the provider names it, the record has moved past this code.

4Documentation

What the chart must show

A provider-stated diagnosis of anemia in the assessment, not a flagged lab value
The complete blood count values that established it
Red cell indices, since microcytic, normocytic, and macrocytic each point toward different code families
Results of any workup performed, including iron studies, B12, folate, and reticulocyte count
A statement that the type or cause remains undetermined, or that the workup is pending
Any underlying chronic disease, with the causal relationship stated rather than implied
Whether the anemia is acute or chronic, and whether blood loss is suspected
Treatment or monitoring, including iron therapy, transfusion, or repeat testing

The most common defect is not a missing detail. It is a chart containing a full anemia workup in the lab section while the assessment still reads anemia, unspecified.

5Decision guide

When to assign D64.9, and when not to

The record says	Assign
Anemia, no type or cause	D64.9
Iron deficiency anemia	D50.9
Iron deficiency anemia from chronic blood loss	D50.0
Vitamin B12 deficiency anemia	D51.9
Folate deficiency anemia	D52.9
Simple chronic anemia	D53.9, which excludes D64.9
Acute blood loss anemia	D62
Anemia due to chronic kidney disease	The CKD code first, then D63.1
Anemia in a neoplastic disease	The neoplasm first, then D63.0
Anemia from antineoplastic chemotherapy	D64.81, with the neoplasm and the adverse effect code
Anemia complicating pregnancy	The obstetric code from O99.0-, with the trimester character
Refractory anemia	D46.-, which the Excludes1 prohibits pairing with D64.9
Low hemoglobin on labs, no diagnosis stated	Nothing; query the provider

Sequencing follows the etiology and manifestation convention. The D63 codes describe anemia in diseases classified elsewhere, which makes them manifestation codes, so the underlying disease is always sequenced first and the anemia code follows.

Query rather than default when the chart holds iron studies, B12 and folate results, or red cell indices that the assessment never carried forward, and when a chronic disease and an anemia sit in the same note with no stated link between them.

6Tabular list

Instructional notes at D64 and above

Note	Content
Excludes1 at D64	Refractory anemia (D46.-), refractory anemia with excess blasts in transformation (C92.0-)
Excludes1 at D53.9	Anemia NOS (D64.9), pointing back at this code
Excludes2 at D50 to D89	Conditions originating in the perinatal period (P00 to P96), complications of pregnancy, childbirth and the puerperium (O00 to O9A), endocrine, nutritional and metabolic diseases (E00 to E88), neoplasms (C00 to D49), symptoms and abnormal findings (R00 to R94), and others
Code first at D63.0, D63.1, D63.8	The underlying neoplasm, chronic kidney disease, or other chronic disease
Code first at I21.A1	The underlying cause, including anemia across D50.0 to D64.9

The two note types indicate different things. Excludes1 is a prohibition, so D64.9 and refractory anemia never share a claim, and neither do D64.9 and nutritional anemia NOS. Excludes2 is a permission, which is why the chapter-level list of other chapters does not stop a patient from carrying codes from both.

The D53.9 relationship is the one worth memorizing. Simple chronic anemia classifies to D53.9, and D53.9 carries an Excludes1 pointing straight back at D64.9. A provider who writes chronic anemia has not written unspecified anemia.

7Comparison

Codes frequently confused with D64.9

Code	Descriptor	Use instead when
D50.9	Iron deficiency anemia, unspecified	Iron deficiency is confirmed, but the cause is not stated
D50.0	Iron deficiency anemia secondary to blood loss (chronic)	Chronic blood loss is documented as the source
D51.9	Vitamin B12 deficiency anemia, unspecified	B12 deficiency is documented
D52.9	Folate deficiency anemia, unspecified	Folate deficiency is documented
D53.9	Nutritional anemia, unspecified	The note says simple chronic anemia, which classifies here
D59.9	Acquired hemolytic anemia, unspecified	Hemolysis is documented as the mechanism
D61.9	Aplastic anemia, unspecified	Marrow failure is documented
D62	Acute posthemorrhagic anemia	Sudden blood loss from a specific event caused the anemia
D63.0	Anemia in neoplastic disease	A malignancy is documented as the cause, sequenced first
D63.1	Anemia in chronic kidney disease	CKD is documented as the cause, sequenced first
D63.8	Anemia in other chronic diseases classified elsewhere	Another chronic disease is documented as the cause
D64.81	Anemia due to antineoplastic chemotherapy	Chemotherapy caused the anemia
D64.89	Other specified anemias	The type is named but has no dedicated code
D46.-	Refractory anemia	Refractory anemia is documented, which the Excludes1 prohibits pairing here

8Claim context

Services commonly reported with D64.9

D64.9 supports office and specialty evaluation and management, and it is the diagnosis behind a large volume of diagnostic laboratory work. Complete blood counts, iron studies, B12 and folate levels, reticulocyte counts, and hemoglobin electrophoresis each carry their own medical necessity requirements, and repeat testing on a stable patient is a recurring audit target.

The therapeutic side is where the unspecified code costs money. Erythropoiesis-stimulating agents, intravenous iron, and transfusion services are governed by coverage policies that list the diagnoses supporting each therapy, and unspecified anemia is frequently absent from those lists. A claim for a therapy the payer covers only for a specified anemia will fail on the diagnosis rather than on the drug.

Confirm the applicable local coverage determination before submitting infusion or injectable therapy with this code, since contractor policy on anemia therapies varies more than most diagnosis categories.

9Denials

Coding errors that cause denials

Error	Correction
Defaulting to D64.9 when the workup identifies iron, B12, or folate deficiency	Assign the code matching the confirmed deficiency
Reporting D64.9 alongside D53.9 or a refractory anemia code	Choose one, since the Excludes1 notes prohibit both pairs
Coding D64.9 when the anemia is attributed to chronic kidney disease	Sequence the CKD code first, then D63.1
Sequencing a D63 code ahead of its underlying disease	Reverse the order, since D63 codes are manifestation codes
Assigning D64.9 from a low hemoglobin with no provider diagnosis	Query, since abnormal findings do not establish a diagnosis
Billing an anemia therapy with D64.9	Check the coverage policy, which often requires a specified anemia
Coding D64.9 for anemia complicating pregnancy	Assign the obstetric code with its trimester character
Leaving D64.9 on a problem list across years of specified workups	Update the diagnosis once the type is established

10Sources

Where to verify D64.9

ICD-10-CM Official Guidelines for Coding and Reporting

Etiology and manifestation sequencing, and the rules on coding from abnormal findings

The ICD-10-CM Tabular List at D64, D63, and D53

The Excludes1 notes, the code-first instructions, and the back-reference from D53.9

The CMS ICD-10 code page

Current code files and the annual addenda

AHA Coding Clinic

Published advice on anemia in chronic disease, chemotherapy-induced anemia, and provider queries

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Last reviewed August 2026

This page is a free reference for billing and coding teams and is not coding, legal, or clinical advice. Code selection depends on the documentation in the record and on the policy of the payer being billed. Verify every code, instructional note, and sequencing rule against the current ICD-10-CM files and the Official Guidelines for Coding and Reporting for the applicable date of service. ICD-10-CM is maintained by the CDC's National Center for Health Statistics and published by CMS. CPT is a registered trademark of the American Medical Association. TruCare is not affiliated with CMS, NCHS, the AHA, or the AMA.