ICD-10-CM Code C91.1

Chronic lymphocytic leukemia of B-cell type

Version 2021 Non-Billable Code

Not Valid for Submission

C91.1 is a "header" nonspecific and non-billable 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 valid for the year 2021 for the submission of HIPAA-covered transactions.

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

Consider the following ICD-10 codes with a higher level of specificity:

  • C91.10 - Chronic lymphocytic leukemia of B-cell type not having achieved remission
  • C91.11 - Chronic lymphocytic leukemia of B-cell type in remission
  • C91.12 - 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 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.
  • Lymphoplasmacytic leukemia
  • Richter syndrome

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.
  • lymphoplasmacytic lymphoma C83.0

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:


Code Classification

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

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients


Chronic Lymphocytic Leukemia

Also called: CLL

Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, the bone marrow produces abnormal white blood cells. These cells crowd out the healthy blood cells, making it hard for blood to do its work. In chronic lymphocytic leukemia (CLL), there are too many lymphocytes, a type of white blood cell.

CLL is the second most common type of leukemia in adults. It often occurs during or after middle age, and is rare in children.

Usually CLL does not cause any symptoms. If you have symptoms, they may include

  • Painless swelling of the lymph nodes in the neck, underarm, stomach, or groin
  • Fatigue
  • Pain or a feeling of fullness below the ribs
  • Fever and infection
  • Weight loss

Tests that examine the blood, bone marrow, and lymph nodes diagnose CLL. Your doctor may choose to just monitor you until symptoms appear or change. Treatments include radiation therapy, chemotherapy, surgery to remove the spleen, and targeted therapy. Targeted therapy uses substances that attack cancer cells or block the growth and spread of cancer cells.

NIH: National Cancer Institute

  • After chemotherapy - discharge (Medical Encyclopedia)
  • B-cell leukemia/lymphoma panel (Medical Encyclopedia)
  • Bone marrow transplant (Medical Encyclopedia)
  • Bone marrow transplant - discharge (Medical Encyclopedia)
  • Chronic lymphocytic leukemia (CLL) (Medical Encyclopedia)

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