ICD-10-CM C91 is the diagnosis code for Lymphoid leukemia. This code falls under the section "Malignant neoplasms of lymphoid, hematopoietic and related tissue" within Chapter 2 — Neoplasms (C00-D49). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions should never be coded at the same time as C91. They are mutually exclusive:
Understanding where C91 sits in the ICD-10-CM classification helps ensure proper coding:
No, C91 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
C91 is the ICD-10-CM diagnosis code for "Lymphoid leukemia". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
C91 is located in Section C81-C96 — "Malignant neoplasms of lymphoid, hematopoietic and related tissue" within Chapter 2 of the ICD-10-CM Tabular List.
C91 has 9 sub-code(s) that provide more specific detail: C91.0, C91.1, C91.3, C91.4, C91.5 and more.
Use C91 when the patients documented diagnosis matches "Lymphoid leukemia" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Lymphoid leukemia is C91.
No, C91 is non-billable. Use a more specific sub-code for primary diagnosis billing.
C91 is in Chapter 2 of the ICD-10-CM Tabular List.
Type 1 Excludes for C91 include: personal history of leukemia (Z85.6).
Yes, C91 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.