C91
Lymphoid leukemia
Choose the additional character
C91 needs more characters to be billable. Pick the specific code below.
- C91.0Acute lymphoblastic leukemia [ALL]More levels
- C91.1Chronic lymphocytic leukemia of B-cell typeMore levels
- C91.3Prolymphocytic leukemia of B-cell typeMore levels
- C91.4Hairy cell leukemiaMore levels
- C91.5Adult T-cell lymphoma/leukemia (HTLV-1-associated)More levels
- C91.6Prolymphocytic leukemia of T-cell typeMore levels
- C91.9Lymphoid leukemia, unspecifiedMore levels
- C91.AMature B-cell leukemia Burkitt-typeMore levels
- C91.ZOther lymphoid leukemiaMore levels
This code does not map to a risk-adjusting HCC in the loaded models.
Coding notes
Excludes 1 never coded together · Excludes 2 may co-exist
personal history of leukemia (Z85.6)
Functional activity All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm. Morphology [Histology] Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes. Primary malignant neoplasms overlapping site boundaries A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned. Malignant neoplasm of ectopic tissue Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9). (C00-C96) Malignant neoplasms (C00-C96) (C00-C75) Malignant neoplasms, stated or presumed to be primary (of specified sites), and certain specified histologies, except neuroendocrine, and of lymphoid, hematopoietic and related tissue (C00-C75)
Official Guidelines for C91
FY 2026 ›Subsections
- I.C.2.aAdmission/Encounter for treatment of primary site
- I.C.2.bAdmission/Encounter for treatment of secondary site
- I.C.2.cCoding and sequencing of complications
- I.C.2.dPrimary malignancy previously excised
- I.C.2.eAdmissions/Encounters involving antineoplastic chemotherapy, immunotherapy and radiation therapy
- I.C.2.fAdmission/encounter to determine extent of malignancy
- I.C.2.gSymptoms, signs, and abnormal findings listed in Chapter 18 associated with neoplasms
- I.C.2.hAdmission/encounter for pain control/management
- I.C.2.iMalignancy in two or more noncontiguous sites
- I.C.2.jDisseminated malignant neoplasm, unspecified
- I.C.2.kMalignant neoplasm without specification of site
- I.C.2.lSequencing of neoplasm codes
- I.C.2.mCurrent malignancy versus personal history of malignancy
- I.C.2.nLeukemia, Multiple Myeloma, and Malignant Plasma Cell
- I.C.2.oAftercare following surgery for neoplasm
- I.C.2.pFollow-up care for completed treatment of a malignancy
- I.C.2.qProphylactic organ removal for prevention of malignancy
- I.C.2.rMalignant neoplasm associated with transplanted organ
- I.C.2.sBreast Implant Associated Anaplastic Large Cell Lymphoma
- I.C.2.tSecondary malignant neoplasm of lymphoid tissue