C91
ICD-10Non-billable categoryLymphoid leukemia
Official ICD-10-CM descriptor (FY2026)
Lymphoid leukemia
C91 is a category heading, not a billable code. CMS does not accept it on a claim; report one of the more specific codes beneath it.
Excludes1
Not coded here. An Excludes1 code should never be reported at the same time as the code above it.
- personal history of leukemia (Z85.6)
More specific codes under C91
- C91.0Acute lymphoblastic leukemia [ALL]category
- C91.1Chronic lymphocytic leukemia of B-cell typecategory
- C91.3Prolymphocytic leukemia of B-cell typecategory
- C91.4Hairy cell leukemiacategory
- C91.5Adult T-cell lymphoma/leukemia (HTLV-1-associated)category
- C91.6Prolymphocytic leukemia of T-cell typecategory
- C91.AMature B-cell leukemia Burkitt-typecategory
- C91.ZOther lymphoid leukemiacategory
- C91.9Lymphoid leukemia, unspecifiedcategory
Where this code sits
- Chapter
- 2. Neoplasms (C00-D49)
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ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.