2022 ICD-10-CM Code C91.1

Chronic lymphocytic leukemia of B-cell type

Version 2021

Not Valid for Submission

ICD-10:C91.1
Short Description:Chronic lymphocytic leukemia of B-cell type
Long Description:Chronic lymphocytic leukemia of B-cell type

Code Classification

  • Neoplasms (C00–D48)
    • Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96)
      • Lymphoid leukemia (C91)

C91.1 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of chronic lymphocytic leukemia of b-cell type. The code is not specific and is NOT valid for the year 2022 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 for Chronic lymphocytic leukemia of B-cell type

Non-specific codes like C91.1 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10 codes with a higher level of specificity when coding for chronic lymphocytic leukemia of b-cell type:

  • 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

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code C91.1:


Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.

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.

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code C91.1 are found in the index:

Information for Patients


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:

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:

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

How is chronic lymphocytic leukemia (CLL) diagnosed?

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

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

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 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 (First year ICD-10-CM implemented into the HIPAA code set)