C91.1
Non-billableChronic lymphocytic leukemia of B-cell type
C91.1 is the ICD-10-CM code for Chronic lymphocytic leukemia of B-cell type. It is a non-billable category code — use a more specific child code such as C91.10 for billing.
C00-D49 Neoplasms
What this means — in plain language
MedlinePlus · NIHWhat 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: White blood cells help your body fight infection Red blood cells deliver oxygen from your lungs to your tissues and organs Platelets help…
Read more about Chronic Lymphocytic Leukemia at MedlinePlus ↗Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.
Includes
- •Lymphoplasmacytic leukemia
- •Richter syndrome
Excludes1 — not coded here
- •lymphoplasmacytic lymphoma (C83.0-)
Frequently asked questions
- What is ICD-10 code C91.1?
- C91.1 is the ICD-10-CM code for "Chronic lymphocytic leukemia of B-cell type". It falls under C00-D49 Neoplasms.
- Is C91.1 a billable code?
- No — C91.1 is a non-billable header code. Use a more specific child code (such as C91.10) for billing.
- What are the subcodes of C91.1?
- C91.1 has 3 more specific child codes, including C91.10, C91.11, C91.12.
- What is excluded from C91.1?
- Excludes1 (not coded here): lymphoplasmacytic lymphoma (C83.0-).
Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.
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