C91.00 is the authoritative medical code for Acute lymphoblastic leukemia not having achieved remission. This classification is used in medical billing and clinical recording to specify the clinical criteria for acute lymphoblastic leukemia not having achieved remission (ICD-10-CM C91.00), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Official Registry Overview & Definition
Acute lymphoblastic leukemia not having achieved remission is a billable ICD-10-CM diagnosis code C91.00. Inclusion terms: Acute lymphoblastic leukemia with failed remission; Acute lymphoblastic leukemia NOS. Excludes1 (not coded here): personal history of leukemia Z85.6. Excludes2 (not included here): Kaposi's sarcoma of lymph nodes C46.3; secondary and unspecified neoplasm of lymph nodes C77.-; secondary neoplasm of bone marrow C79.52; secondary neoplasm of spleen C78.89.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for C91.00 in the official ICD-10-CM tabular list.
Inclusion Terms
Alternative terms the tabular list files under this code.
- Acute lymphoblastic leukemia with failed remission
- Acute lymphoblastic leukemia NOS
Excludes1 — Not Coded Here
Conditions that can never be reported with this code; the two are mutually exclusive.
- personal history of leukemia Z85.6
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- Kaposi's sarcoma of lymph nodes C46.3
- secondary and unspecified neoplasm of lymph nodes C77.-
- secondary neoplasm of bone marrow C79.52
- secondary neoplasm of spleen C78.89
Frequently Asked Questions (FAQ) & Clinical Guidance
What can't be coded together with C91.00?
Per Excludes1 instructions, C91.00 must not be reported with: personal history of leukemia (Z85.6).
Can C91.00 be reported alongside related conditions?
Per Excludes2 instructions, C91.00 and the following may both be reported when both are present: Kaposi's sarcoma of lymph nodes (C46.3); secondary and unspecified neoplasm of lymph nodes (C77.-); secondary neoplasm of bone marrow (C79.52); secondary neoplasm of spleen (C78.89).
What conditions are included under C91.00?
Acute lymphoblastic leukemia not having achieved remission includes: Acute lymphoblastic leukemia with failed remission; Acute lymphoblastic leukemia NOS.
Codes in This Family (36)
Official ICD-10-CM classifications in the same code family as C91.00, with their registry titles.
- C91 — Lymphoid leukemia
- C91.0 — Acute lymphoblastic leukemia [ALL]
- C91.01 — Acute lymphoblastic leukemia, in remission
- C91.02 — Acute lymphoblastic leukemia, in relapse
- C91.1 — Chronic lymphocytic leukemia of B-cell type
- 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
- C91.3 — Prolymphocytic leukemia of B-cell type
- 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
- C91.4 — Hairy cell leukemia
- C91.40 — Hairy cell leukemia not having achieved remission
- C91.41 — Hairy cell leukemia, in remission
- C91.42 — Hairy cell leukemia, in relapse
- C91.5 — Adult T-cell lymphoma/leukemia (HTLV-1-associated)
- 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
- C91.6 — Prolymphocytic leukemia of T-cell type
- 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
- C91.9 — Lymphoid leukemia, unspecified
- C91.90 — Lymphoid leukemia, unspecified not having achieved remission
- C91.91 — Lymphoid leukemia, unspecified, in remission
- C91.92 — Lymphoid leukemia, unspecified, in relapse
- C91.A — Mature B-cell leukemia Burkitt-type
- 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.Z — Other lymphoid leukemia
- C91.Z0 — Other lymphoid leukemia not having achieved remission
- C91.Z1 — Other lymphoid leukemia, in remission
- C91.Z2 — Other lymphoid leukemia, in relapse
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:
ICD Code C86.00
Extranodal NK/T-cell lymphoma, nasal type not having achieved remission
ICD Code C88.00
Waldenström macroglobulinemia not having achieved remission
ICD Code C93.00
Acute monoblastic/monocytic leukemia, not having achieved remission
ICD Code C95.00
Acute leukemia of unspecified cell type not having achieved remission