Version 2024

2024 ICD-10-CM Diagnosis Code C91

Lymphoid leukemia

ICD-10-CM Code:
C91
ICD-10 Code for:
Lymphoid leukemia
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Neoplasms
    (C00–D49)
    • Malignant neoplasms of lymphoid, hematopoietic and related tissue
      (C81-C96)
      • Lymphoid leukemia
        (C91)

C91 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of lymphoid leukemia. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Lymphoid leukemia

Non-specific codes like C91 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for lymphoid leukemia:

  • C91.0 for Acute lymphoblastic leukemia [ALL] - NON-BILLABLE CODE

  • Use C91.00 for Acute lymphoblastic leukemia not having achieved remission - BILLABLE CODE

  • Use C91.01 for Acute lymphoblastic leukemia, in remission - BILLABLE CODE

  • Use C91.02 for Acute lymphoblastic leukemia, in relapse - BILLABLE CODE

  • C91.1 for Chronic lymphocytic leukemia of B-cell type - NON-BILLABLE CODE

  • Use C91.10 for Chronic lymphocytic leukemia of B-cell type not having achieved remission - BILLABLE CODE

  • Use C91.11 for Chronic lymphocytic leukemia of B-cell type in remission - BILLABLE CODE

  • Use C91.12 for Chronic lymphocytic leukemia of B-cell type in relapse - BILLABLE CODE

  • C91.3 for Prolymphocytic leukemia of B-cell type - NON-BILLABLE CODE

  • Use C91.30 for Prolymphocytic leukemia of B-cell type not having achieved remission - BILLABLE CODE

  • Use C91.31 for Prolymphocytic leukemia of B-cell type, in remission - BILLABLE CODE

  • Use C91.32 for Prolymphocytic leukemia of B-cell type, in relapse - BILLABLE CODE

  • C91.4 for Hairy cell leukemia - NON-BILLABLE CODE

  • Use C91.40 for Hairy cell leukemia not having achieved remission - BILLABLE CODE

  • Use C91.41 for Hairy cell leukemia, in remission - BILLABLE CODE

  • Use C91.42 for Hairy cell leukemia, in relapse - BILLABLE CODE

  • C91.5 for Adult T-cell lymphoma/leukemia (HTLV-1-associated) - NON-BILLABLE CODE

  • Use C91.50 for Adult T-cell lymphoma/leukemia (HTLV-1-associated) not having achieved remission - BILLABLE CODE

  • Use C91.51 for Adult T-cell lymphoma/leukemia (HTLV-1-associated), in remission - BILLABLE CODE

  • Use C91.52 for Adult T-cell lymphoma/leukemia (HTLV-1-associated), in relapse - BILLABLE CODE

  • C91.6 for Prolymphocytic leukemia of T-cell type - NON-BILLABLE CODE

  • Use C91.60 for Prolymphocytic leukemia of T-cell type not having achieved remission - BILLABLE CODE

  • Use C91.61 for Prolymphocytic leukemia of T-cell type, in remission - BILLABLE CODE

  • Use C91.62 for Prolymphocytic leukemia of T-cell type, in relapse - BILLABLE CODE

  • C91.9 for Lymphoid leukemia, unspecified - NON-BILLABLE CODE

  • Use C91.90 for Lymphoid leukemia, unspecified not having achieved remission - BILLABLE CODE

  • Use C91.91 for Lymphoid leukemia, unspecified, in remission - BILLABLE CODE

  • Use C91.92 for Lymphoid leukemia, unspecified, in relapse - BILLABLE CODE

  • C91.A for Mature B-cell leukemia Burkitt-type - NON-BILLABLE CODE

  • Use C91.A0 for Mature B-cell leukemia Burkitt-type not having achieved remission - BILLABLE CODE

  • Use C91.A1 for Mature B-cell leukemia Burkitt-type, in remission - BILLABLE CODE

  • Use C91.A2 for Mature B-cell leukemia Burkitt-type, in relapse - BILLABLE CODE

  • C91.Z for Other lymphoid leukemia - NON-BILLABLE CODE

  • Use C91.Z0 for Other lymphoid leukemia not having achieved remission - BILLABLE CODE

  • Use C91.Z1 for Other lymphoid leukemia, in remission - BILLABLE CODE

  • Use C91.Z2 for Other lymphoid leukemia, in relapse - BILLABLE CODE

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • personal history of leukemia Z85.6

Patient Education


Acute Lymphocytic Leukemia

What is leukemia?

Leukemia is a term for cancers of the blood cells. Leukemia starts in blood-forming tissues such as the bone marrow. Your bone marrow makes the cells which will develop into white blood cells, red blood cells, and platelets. Each type of cell has a different job:

  • White blood cells help your body fight infection
  • Red blood cells deliver oxygen from your lungs to your tissues and organs
  • Platelets help form clots to stop bleeding

When you have leukemia, your bone marrow makes large numbers of abnormal cells. This problem most often happens with white blood cells. These abnormal cells build up in your bone marrow and blood. They crowd out the healthy blood cells and make it hard for your cells and blood to do their work.

What is acute lymphocytic leukemia (ALL)?

Acute lymphocytic leukemia is a type of acute leukemia. It's also called ALL and acute lymphoblastic leukemia. "Acute" means that it usually gets worse quickly if it's not treated. ALL is the most common type of cancer in children. It can also affect adults.

In ALL, the bone marrow makes too many lymphocytes, a type of white blood cell. These cells normally help your body fight infection. But in ALL, they are abnormal and cannot fight infection very well. They also crowd out the healthy cells, which can lead to infection, anemia, and easy bleeding. These abnormal cells can also spread to other parts of the body, including the brain and spinal cord.

What causes acute lymphocytic leukemia (ALL)?

ALL happens when there are changes in the genetic material (DNA) in bone marrow cells. The cause of these genetic changes is unknown. However, there are certain factors that raise your risk of ALL.

Who is at risk for acute lymphocytic leukemia (ALL)?

The factors that raise your risk of ALL include:

  • Being male
  • Being white
  • Being over age 70
  • Having had chemotherapy or radiation therapy
  • Having been exposed to high levels of radiation
  • Having certain genetic disorders, such as Down syndrome

What are the symptoms of acute lymphocytic leukemia (ALL)?

The signs and symptoms of ALL include:

  • Weakness or feeling tired
  • Fever or night sweats
  • Easy bruising or bleeding
  • Petechiae, which are tiny red dots under the skin. They are caused by bleeding.
  • Shortness of breath
  • Weight loss or loss of appetite
  • Pain in the bones or stomach
  • Pain or feeling of fullness below the ribs
  • Swollen lymph nodes - you may notice them as painless lumps in the neck, underarm, stomach, or groin
  • Having had many infections

How is acute lymphocytic leukemia (ALL) diagnosed?

Your health care provider may use many tools to diagnose ALL and figure out which subtype you have:

  • A physical exam
  • A medical history
  • Blood tests, such as
    • Complete blood count (CBC) with differential
    • Blood chemistry tests such as a basic metabolic panel (BMP), comprehensive metabolic panel (CMP), kidney function tests, liver function tests, and electrolyte panel
    • Blood smear
  • Bone marrow tests. There are two main types - bone marrow aspiration and bone marrow biopsy. Both tests involve removing a sample of bone marrow and bone. The samples are sent to a lab for testing.
  • Genetic tests to look for gene and chromosome changes

If you are diagnosed with ALL, you may have additional tests to see whether the cancer has spread. These include imaging tests and a lumbar puncture, which is a procedure to collect and test cerebrospinal fluid (CSF).

What are the treatments for acute lymphocytic leukemia (ALL)?

Treatments for ALL include:

  • Chemotherapy
  • Radiation therapy
  • Chemotherapy with stem cell transplant
  • Targeted therapy, which uses drugs or other substances that attack specific cancer cells with less harm to normal cells

Treatment is usually done in two phases:

  • The goal of the first phase is to kill the leukemia cells in the blood and bone marrow. This treatment puts the leukemia into remission. Remission means that the signs and symptoms of cancer are reduced or have disappeared.
  • The second phase is known as post-remission therapy. Its goal is to prevent a relapse (return) of the cancer. It involves killing any remaining leukemia cells that may not be active but could begin to regrow.

Treatment during both phases also usually includes central nervous system (CNS) prophylaxis therapy. This therapy helps prevent the spread of leukemia cells to the brain and spinal cord. It may be high dose chemotherapy or chemotherapy injected into the spinal cord. It also sometimes includes radiation therapy.

NIH: National Cancer Institute


[Learn More in MedlinePlus]

Chronic Lymphocytic Leukemia

What is leukemia?

Leukemia is a term for cancers of the blood cells. Leukemia starts in blood-forming tissues such as the bone marrow. Your bone marrow makes the cells which will develop into white blood cells, red blood cells, and platelets. Each type of cell has a different job:

  • White blood cells help your body fight infection
  • Red blood cells deliver oxygen from your lungs to your tissues and organs
  • Platelets help form clots to stop bleeding

When you have leukemia, your bone marrow makes large numbers of abnormal cells. This problem most often happens with white blood cells. These abnormal cells build up in your bone marrow and blood. They crowd out the healthy blood cells and make it hard for your cells and blood to do their work.

What is chronic lymphocytic leukemia (CLL)?

Chronic lymphocytic leukemia (CLL) is a type of chronic leukemia. "Chronic" means that the leukemia usually gets worse slowly. In CLL, the bone marrow makes abnormal lymphocytes (a type of white blood cell). When the abnormal cells crowd out the healthy cells, it can lead to infection, anemia, and easy bleeding. The abnormal cells can also spread outside the blood to other parts of the body. CLL is one of the most common types of leukemia in adults. It often occurs during or after middle age. It is rare in children.

What causes chronic lymphocytic leukemia (CLL)?

CLL happens when there are changes in the genetic material (DNA) in bone marrow cells. The cause of these genetic changes is unknown, so it's hard to predict who might get CLL. There are a few factors that might raise your risk.

Who is at risk for chronic lymphocytic leukemia (CLL)?

It is hard to predict who will get CLL. There are a few factors that could raise your risk:

  • Age - your risk goes up as you get older. Most people who are diagnosed with CLL are over 50.
  • Family history of CLL and other blood and bone marrow diseases
  • Racial/ethnic group - CLL is more common in whites than in people from other racial or ethnic groups
  • Exposure to certain chemicals, including Agent Orange, a chemical that was used in the Vietnam War

What are the symptoms of chronic lymphocytic leukemia (CLL)?

In the beginning, CLL does not cause any symptoms. Later, you can have symptoms such as:

  • Swollen lymph nodes - you may notice them as painless lumps in the neck, underarm, stomach, or groin
  • Weakness or feeling tired
  • Pain or a feeling of fullness below the ribs
  • Fever and infection
  • Easy bruising or bleeding
  • Petechiae, which are tiny red dots under the skin. They are caused by bleeding.
  • Weight loss for no known reason
  • Drenching night sweats

How is chronic lymphocytic leukemia (CLL) diagnosed?

Your health care provider may use many tools to diagnose CLL:

  • A physical exam
  • A medical history
  • Blood tests, such as a complete blood count (CBC) with differential and blood chemistry tests. Blood chemistry tests measure different substances in the blood, including electrolytes, fats, proteins, glucose (sugar), and enzymes. Specific blood chemistry tests include a basic metabolic panel (BMP), a comprehensive metabolic panel (CMP), kidney function tests, liver function tests, and an electrolyte panel.
  • Flow cytometry tests, which check for leukemia cells and identify which type of leukemia it is. The tests can be done on blood, bone marrow, or other tissue.
  • Genetic tests to look for gene and chromosome changes

If you are diagnosed with CLL, you may have additional tests to see whether the cancer has spread. These include imaging tests and bone marrow tests.

What are the treatments for chronic lymphocytic leukemia (CLL)?

Treatments for CLL include:

  • Watchful waiting, which means that you don't get treatment right away. Your health care provider regularly checks to see if your signs or symptoms appear or change.
  • Targeted therapy, which uses drugs or other substances that attack specific cancer cells with less harm to normal cells.
  • Chemotherapy
  • Radiation therapy
  • Immunotherapy
  • Chemotherapy with bone marrow or stem cell transplant

The goals of treatment are to slow the growth of the leukemia cells and to give you long periods of remission. Remission means that the signs and symptoms of cancer are reduced or have disappeared. The CLL may come back after remission, and you may need more treatment.

NIH: National Cancer Institute


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.