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ICD-10-CM · FY 2026 APRIL UPDATE

C91

Lymphoid leukemia

Diagnosis reference

Nonbillable category

This entry is a category or subcategory. Choose the appropriate billable descendant based on the clinical documentation.

Effective periodOctober 1, 2026–September 30, 2027
SourceCMS ICD-10-CM order file
ClassificationDiagnosis · clinical modification

Related entries

Up to 30 descendants in this category

CODEDESCRIPTIONTYPE
C91.0Acute lymphoblastic leukemia [ALL]Category
C91.00Acute lymphoblastic leukemia not having achieved remissionBillable
C91.01Acute lymphoblastic leukemia, in remissionBillable
C91.02Acute lymphoblastic leukemia, in relapseBillable
C91.1Chronic lymphocytic leukemia of B-cell typeCategory
C91.10Chronic lymphocytic leukemia of B-cell type not having achieved remissionBillable
C91.11Chronic lymphocytic leukemia of B-cell type in remissionBillable
C91.12Chronic lymphocytic leukemia of B-cell type in relapseBillable
C91.3Prolymphocytic leukemia of B-cell typeCategory
C91.30Prolymphocytic leukemia of B-cell type not having achieved remissionBillable
C91.31Prolymphocytic leukemia of B-cell type, in remissionBillable
C91.32Prolymphocytic leukemia of B-cell type, in relapseBillable
C91.4Hairy cell leukemiaCategory
C91.40Hairy cell leukemia not having achieved remissionBillable
C91.41Hairy cell leukemia, in remissionBillable
C91.42Hairy cell leukemia, in relapseBillable
C91.5Adult T-cell lymphoma/leukemia (HTLV-1-associated)Category
C91.50Adult T-cell lymphoma/leukemia (HTLV-1-associated) not having achieved remissionBillable
C91.51Adult T-cell lymphoma/leukemia (HTLV-1-associated), in remissionBillable
C91.52Adult T-cell lymphoma/leukemia (HTLV-1-associated), in relapseBillable
C91.6Prolymphocytic leukemia of T-cell typeCategory
C91.60Prolymphocytic leukemia of T-cell type not having achieved remissionBillable
C91.61Prolymphocytic leukemia of T-cell type, in remissionBillable
C91.62Prolymphocytic leukemia of T-cell type, in relapseBillable
C91.AMature B-cell leukemia Burkitt-typeCategory
C91.A0Mature B-cell leukemia Burkitt-type not having achieved remissionBillable
C91.A1Mature B-cell leukemia Burkitt-type, in remissionBillable
C91.A2Mature B-cell leukemia Burkitt-type, in relapseBillable
C91.ZOther lymphoid leukemiaCategory
C91.Z0Other lymphoid leukemia not having achieved remissionBillable

Use the complete reference

This reference does not reproduce the full tabular hierarchy, inclusion notes, Excludes1/2 notes, sequencing instructions, or seventh-character rules. Review the official tables and coding guidelines.

Open official CMS files

ICD-10-CM codes describe diagnoses. They do not have an independent Medicare PFS reimbursement amount, and billability alone does not establish coverage.