ICD10Check
CheckerBrowseOpen

C91.1

⚠ Non-billable (Header)

Chronic lymphocytic leukemia of B-cell type

Neoplasms (C00-D49)

⚠️ This is a category header code — not billable. Use a more specific child code below.

Check This Code

Also Known As

Lymphoplasmacytic leukemiaRichter syndrome

❌ Excludes1

direct

Cannot be coded with C91.1

  • • lymphoplasmacytic lymphoma (C83.0-)

❌ Excludes1

inherited from C91

Rules from parent category C91: Lymphoid leukemia

  • • personal history of leukemia (Z85.6)

Child Codes (3)

C91.10Chronic lymphocytic leukemia of B-cell type not having achieved remissionC91.11Chronic lymphocytic leukemia of B-cell type in remissionC91.12Chronic lymphocytic leukemia of B-cell type in relapse

🧪 Validate Combinations

Add C91.1 to the Excludes Checker to validate against your full code list.

Open in Checker →

Code Information

CodeC91.1
BillableNo — Header code
ParentC91
CategoryNeoplasms (C00-D49)
Excludes12 rule(s)
Excludes20 note(s)
Child codes3

Data Source

CMS ICD-10-CM 2026 Tabular List

Updated October 1, 2025 (FY2026)