2021 ICD-10-CM Code C91.Z2

Other lymphoid leukemia, in relapse

Version 2021

Valid for Submission

C91.Z2 is a billable diagnosis code used to specify a medical diagnosis of other lymphoid leukemia, in relapse. The code C91.Z2 is valid during the fiscal year 2021 from October 01, 2020 through September 30, 2021 for the submission of HIPAA-covered transactions.

ICD-10:C91.Z2
Short Description:Other lymphoid leukemia, in relapse
Long Description:Other lymphoid leukemia, in relapse

Code Classification

Convert C91.Z2 to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code C91.Z2 its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

Information for Patients


Acute Lymphocytic Leukemia

Also called: ALL, Acute lymphoblastic leukemia

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, however, 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 acute lymphocytic leukemia (ALL), also called acute lymphoblastic leukemia, there are too many of specific types of white blood cells called lymphocytes or lymphoblasts. ALL is the most common type of cancer in children.

Possible risk factors for ALL include being male, being white, previous chemotherapy treatment, exposure to radiation, and for adults, being older than 70.

Symptoms of ALL include:

Tests that examine the blood and bone marrow diagnose ALL. Treatments include chemotherapy, radiation therapy, stem cell transplants, and targeted therapy. Targeted therapy uses substances that attack cancer cells without harming normal cells. Once the leukemia is in remission, you need additional treatment to make sure that it does not come back.

NIH: National Cancer Institute


[Learn More in MedlinePlus]

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)