ICD-10-CM category C91: Lymphoid leukemia
Category C91 is a heading in chapter 2 (Neoplasms (C00-D49)), section Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96). It is not billable; report one of the 27 complete codes below.
Notes that apply to every C91 code
- Excludes1 (never coded together)
- personal history of leukemia (Z85.6)
Billable codes in C91
| Code | Description |
|---|---|
| C91.00 | Acute lymphoblastic leukemia not having achieved remission |
| C91.01 | Acute lymphoblastic leukemia, in remission |
| C91.02 | Acute lymphoblastic leukemia, in relapse |
| C91.10 | Chronic lymphocytic leukemia of B-cell type not having achieved remission |
| C91.11 | Chronic lymphocytic leukemia of B-cell type in remission |
| C91.12 | Chronic lymphocytic leukemia of B-cell type in relapse |
| C91.30 | Prolymphocytic leukemia of B-cell type not having achieved remission |
| C91.31 | Prolymphocytic leukemia of B-cell type, in remission |
| C91.32 | Prolymphocytic leukemia of B-cell type, in relapse |
| C91.40 | Hairy cell leukemia not having achieved remission |
| C91.41 | Hairy cell leukemia, in remission |
| C91.42 | Hairy cell leukemia, in relapse |
| C91.50 | Adult T-cell lymphoma/leukemia (HTLV-1-associated) not having achieved remission |
| C91.51 | Adult T-cell lymphoma/leukemia (HTLV-1-associated), in remission |
| C91.52 | Adult T-cell lymphoma/leukemia (HTLV-1-associated), in relapse |
| C91.60 | Prolymphocytic leukemia of T-cell type not having achieved remission |
| C91.61 | Prolymphocytic leukemia of T-cell type, in remission |
| C91.62 | Prolymphocytic leukemia of T-cell type, in relapse |
| C91.90 | Lymphoid leukemia, unspecified not having achieved remission |
| C91.91 | Lymphoid leukemia, unspecified, in remission |
| C91.92 | Lymphoid leukemia, unspecified, in relapse |
| C91.A0 | Mature B-cell leukemia Burkitt-type not having achieved remission |
| C91.A1 | Mature B-cell leukemia Burkitt-type, in remission |
| C91.A2 | Mature B-cell leukemia Burkitt-type, in relapse |
| C91.Z0 | Other lymphoid leukemia not having achieved remission |
| C91.Z1 | Other lymphoid leukemia, in remission |
| C91.Z2 | Other lymphoid leukemia, in relapse |
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.
- ICD-10-CM FY2027 tabular order file (category titles)Version FY2027 · effective 2026-10-01 · file icd10cm_order_2027.txtSHA-256 38981fb2c1226e2b…
- ICD-10-CM FY2027 tabular list (chapter titles and ranges)Version FY2027 · effective 2026-10-01 · file 2027-code-tables-tabular-index.zipSHA-256 37baa476323714be…
- ICD-10-CM FY2027 code descriptions addenda (codes added, deleted and revised)Version FY2027 · effective 2026-10-01 · file icd10cm_codes_addenda_2027.txtSHA-256 cfba025073235af4…
- ICD-10 MS-DRG Definitions Manual v44 (text)Version v44 · effective 2026-10-01 · file fy2027-fr-icd10-ms-drg-definitions-manual-files-v44.zipSHA-256 ae4f6c11727fe91f…
- IPPS FY2027 Tables 6A-6K: new, invalid and revised ICD-10-CM/PCS codes, CC/MCC list changes and CC exclusionsVersion FY2027 (final rule; not reissued by CN3) · effective 2026-10-01 · file fy2027-ipps-fr-tables-6a-6k.zipSHA-256 ca0af87b0869a405…
- ICD-10-CM FY2027 POA-exempt codes (full list, additions, deletions and revisions)Version FY2027 · effective 2026-10-01 · file 2027-poa-exempt-codes.zipSHA-256 03f55091045024d0…
- ICD-10-CM to CMS-HCC V28 mappings, payment year 2027 initialVersion PY2027 initial ICD-10-CM mappings (dates of service 2026) · effective 2027-01-01 · file 2027 Initial ICD-10-CM Mappings.csvSHA-256 9c260b06d0dd2806…
- Medicare Coverage Database, current Billing and Coding Articles exportVersion MCD release 2026-10-08 · effective 2026-10-04 · file article.csvSHA-256 5e95c4a8ac3664be…
Codes from the FY2027 ICD-10-CM files (all chapters). Report the code that matches the documentation and the Official Guidelines; this list is not coding advice.