2021 ICD-10-CM Code C91.6

Prolymphocytic leukemia of T-cell type

Version 2021

Not Valid for Submission

C91.6 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of prolymphocytic leukemia of t-cell type. The code is not specific and is NOT valid for the year 2021 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.

ICD-10:C91.6
Short Description:Prolymphocytic leukemia of T-cell type
Long Description:Prolymphocytic leukemia of T-cell type

Code Classification

Specific Coding for Prolymphocytic leukemia of T-cell type

Non-specific codes like C91.6 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 prolymphocytic leukemia of t-cell type:

  • 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

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 C91.6 are found in the index:

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

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


[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)